Facility for Rare Isotope Beams

The discovery of the first neutron star merger, GW170817, signaled a wealth of firsts in physics and represents only the tip of the iceberg of the discovery potential we can achieve in multi-messenger astronomy. In this talk, I present X-ray, optical, and radio observations of GW170817 extending until 2 years after the merger. These observations provide deep insight into the geometry of the jet, energetics, and the merger's local environment. I then connect these observations to the existing population of cosmological short GRBs, demonstrating that the primary difference between the two populations is viewing angle. I also present deep Hubble Space Telescope imaging of GW170817, which allow us to place the first direct constraints on the dynamical formation of the neutron star binary progenitor. Finally, I will discuss results from LIGO/Virgo's 3rd Observing Run thus far, and the bright future ahead for multi-messenger astronomy.

In this talk I will report on recent advances in ab-initio coupled-cluster computations of nuclei starting chiral Hamiltonians with two- and three-nucleon forces. Using high precision coupled-cluster methods we addressed the quenching puzzle of [beta]-decays in nuclei. We showed that this quenching can be explained from two-body currents and many-body correlations. In particular, we made predictions for the Gamow-Teller decay of the heavy nucleus ¹⁰⁰Sn [1,2], and our result is consistent with the recent high precision measurement at RIKEN [3]. I will also show very recent results for medium-mass nuclei and nuclear matter using optimized chiral interactions with explicit delta degrees of freedom. Binding energies, radii, and saturation properties in nuclear matter are improved compared to existing chiral Hamiltonians. We have also started computations of deformed nuclei using a coupled-cluster approach starting from a deformed Hartree-Fock reference state with promising results for nuclei up to mass A

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50. Last, but not least, I will present a new method that allows for the computation of bulk properties of an atomic nucleus for a million of different model parameters in less than one hour on a standard laptop. The equivalent set of ab-initio coupled-cluster computations would require about 20 years. This speedup enables statistical computing of the chiral nuclear Hamiltonian, and entirely new ways to use experimental data across the nuclear chart to generate new knowledge about the strong nuclear interaction [4]. [1] T. D. Morris, et al, Phys. Rev. Lett. 120, 152503 (2018) [2] P. Gysbers, et al, Nature Physics 15, 428-431 (2019) [3] D. Lubos et al., Phys. Rev. Lett. 122, 222502 (2019) [4] A. Ekstr

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m and G. Hagen, Phys. Rev. Lett. 123, 252501 (2019)

In November 2019, a firework of articles in scientific publications and non-scientific newspapers announced the possible discovery of a new boson of a mass of about 17 MeV as eventually observed in pair creation in light nuclei that could be related to a fifth force. The indications ("Atomky anomaly"), often quite contradictory, of such a boson have quite a long history going back more than 30 years. The renewed interest was partially motivated by a very recent claim, by the same team, to have observed this boson in the 3H+proton system giving a result compatible with the previous results of the 7Li+proton system. Both results were obtained by only one team and merit closer scrutiny. An experiment is planned in the near future with the pAT-TPC.

Symmetries and conservation laws lie at the foundation of the physical sciences and manifest themselves throughout the natural world. Within the atomic nucleus, an underlying symmetry exists due to the similarity between protons and neutrons. The strong short-range nuclear force that binds these particles together is found to be nearly independent of their electric charge. From the relative invariance of the nuclear interaction, a striking symmetry emerges in the quantum states of mirror nuclei whose proton and neutron numbers are exchanged. This fundamental property is an important predictor of nuclear structure and is described within the formalism of isobaric-spin symmetry, which has proved remarkably accurate since its inception in the early 1930's. Recently, we performed an experiment that has revealed, for the first time, a unique violation of mirror symmetry between the ground states of two mirror nuclei, 73Sr and 73Br. The experiment was conducted at the National Superconducting Cyclotron Laboratory (NSCL) and utilized the Beta-Counting Station (BCS) coupled to the Radio-Frequency Fragment Separator (RFFS) to investigate beta-delayed proton emission along the N=Z line. In this talk I will briefly review the concept of mirror symmetry in nuclei and discuss some of its consequences within nuclear physics. I will then describe details of our recent measurement and discuss our observation of ground-state mirror-symmetry breaking in atomic nuclei. This work is supported by the U.S. Department of Energy, Office of Nuclear Physics, under contract number DE-FG02-94ER40848 (UML).

"Vital Nuclear Processes in Core-collapse Supernovae" and "Measurements of alpha-processes relevant for the weak r-process", respectively

Core-collapse supernovae originate from the gravitational collapse of massive stars. These events are a source of neutrinos and a site of elements synthesis. They also play an important role in the evolution of galaxies. Despite being studied for decades, the explosion mechanism is still uncertain. This is in itself an important question, but it also affects the outcome (successful explosion or collapse to a black hole), the remnant left behind, and the detailed conditions under which explosive nucleosynthesis happens. In this talk, I will discuss the recent progress of my group in core-collapse supernova modeling.

In this talk I will present results from high energy density science and applied physics studies in the ATAP Division at Berkeley Lab (http://atap.lbl.gov/). We have recently expanded science at the BELLA petawatt laser from a focus on electron acceleration to include now also experiments on ion acceleration and laser-matter interactions with solid targets [1]. Here, a unique opportunity is warranted by the 1 Hz repetition rate of BELLA, which allows parametric explorations with thousands of shots. One example are nuclear reactions in plasmas and moderately hot targets where unreasonably high values of apparent electron screening potentials have been observed in studies of light ion fusion that can now be investigated with higher precision [2]. Pulsed ion beams provide access to the time domain of ion-solid interactions and they have been used to drive materials very far from equilibrium. I will report on our efforts to develop intense ion beams and on studies of color center qubit formation and damage accumulation in semiconductor devises with intense, pulsed ion beams [3, 4]. References: [1] J.-H. Bin, et al., Rev. Sci. Instr. 90, 053301 (2019) [2] T. Schenkel, et al., J. Appl. Phys. 126, 203302 (2019); C. P. Berlinguette, et al., Nature 570, 45 (2019) [3] J. Schwartz, et al., J. Appl. Phys. 116, 214107 (2014); J. J. Barnard, T. Schenkel, J. Appl. Phys. 122, 195901 (2017) [4] T Schenkel, et al., LLNL-CONF-758685; B. A. Ludewigt, et al., JRERE 36, 96 (2018) Acknowledgments: This work was supported by the Director, Office of Science, Offices of High Energy Physics and Fusion Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, by ARPA-E, and in part also by LDRD funding at Berkeley Lab, by Sandia National Laboratory, and by Google LLC under CRADA between LBNL and Google LLC.

Type-I X-ray bursts (XRBs) are powered by nuclear burning on the surface of an accreting neutron star and consequently model-observation comparisons are sensitive to the model nuclear input. 22Mg(alpha,p)25Al is among the most important reactions which directly impact the XRB light curve. First direct measurement of this was carried out at NSCL using the AT-TPC. Results from this measurement will be presented and impact on XRB model-observations will be discussed.

My talk consists of two parts. The first is about the development of atomic interferometer for 87Rb Bose-Einstein Condensate (BEC) made on atomic chip by using rf field to capture atoms in ring type potential or to separate it into two separations. We will explain the process of implementing BEC and changing the potential using dimple potential. The second part is about the development of collinear laser spectroscopy system as a user of RAON under construction in Korea. We will describe the Collinear Laser Spectroscopy (CLS) system currently being developed in collaboration with TRIUMF in Canada and further research plans.

Deficit-minded thinking is person-centered, and what we colloquially might call a fix-the-student mentality. Such thinking blames students, their families, communities, and/or culture for their underperformance while holding educational institutions, faculty, inequitable policies and practices faultless. Most recruitment and retention programs for underrepresented students in science and engineering are inadvertently deficit-oriented, focusing on individual students and interventions to fix their perceived deficits through activities such as tutoring, advising, or mentoring. The problem with this approach is that it implies that when we simply support the individual student, we thus solve the issue underlying their underrepresentation. In fact, the reverse is often true; when we assist those students, the inequitable structures that necessitate their support remain uncontested. Likewise, the vast majority of published research on underrepresentation in science and engineering education is either explicitly or implicitly deficit-based. Research often focuses on why underrepresented students either underperform or leave the discipline of science and engineering entirely. We know much less, however, as to why underrepresented students succeed in these fields. Systemic change is necessary to tackle the complexity of recruiting and retaining students marginalized by the education system. In this talk, Dr. Martin calls for research interventions that purposefully employ asset-based approaches and recognize the multiple domains of students lives. Such research and interventions that address systemic inequities, rather than focus on perceived deficits of students, are necessary in order to achieve lasting outcomes. This shift to asset-based perspective is difficult, however, as it necessitates deconstructing practices, beliefs, and policies. In this seminar, we will: (1) explore the idea of deficit thinking in education (2) learn about asset-based frameworks such as community cultural wealth (3) think about how we can begin to transform our educational systems through asset-based approaches to student success and a focus on institutional change.

Classical and quantum chaos - old discussions and new understanding. Classical chaos leads to strong sensitivity of trajectories to initial conditions in all realistic systems. Chaos in quantum systems is frequently claimed to be a remnant of classical chaos. We try to show that the situation is just opposite. Using the nuclear shell model as a testing ground we show the absence of an analog of exponential divergence of trajectories in the exact quantum solution. A quantum system demonstrates the universal way of the evolution of an initial nonstationary state coming to thermal equilibrium.

Stardust grains, which are micrometer-sized particles found in meteorites, formed in the death throes of dying stars and recorded their parent stars nucleosynthetic fingerprint. Analyzing these bona fide stellar condensates allows us to obtain these fingerprints for various stellar events and - in combination with experimental physics, observations, and modeling - allows us to better constrain stellar nucleosynthesis and galactic chemical evolution. In this talk I will present recent isotopic measurements of stardust that inform our understanding of the origin of the elements that formed the solar system, and discuss recent advances and possibilities on exploring galactic chemical evolution. I will also discuss ongoing efforts to experimentally study determine the stellar sites of actinide nucleosynthesis, i.e., the rapid neutron capture process.

The decomposition of the proton mass and spin in terms of the quark and glue components are calculated in lattice QCD. The calculations are carried out with chiral fermions which are needed to addresses the `proton spin crisis'. I will also discuss the status of calculating the hadronic tensor For the neutrino-nucleon scattering in the elastic, resonance, shallow inelastic and deep inelastic scattering regions.

Neutron capture and photodissociation reactions are critical to the synthesis of the heavy elements in stellar environments. Experimental constraints, however, make direct measurement of these cross sections nontrivial. Therefore, it is essential to develop reliable methods for predicting (n,y) and (y,x) reaction cross sections over the mass ranges and Gamow windows appropriate to the r-, s-, and p-processes. One alternative to direct measurements of (y,p) and (y,a), reactions characteristic to the p-process, are inverse reaction cross-section measurement using the y-summing technique. Experiments employing the y-summing technique can now be performed at the University of Notre Dame using the High Efficiency Total Absorption Spectrometer (HECTOR). Commissioning of HECTOR via measurement of resonance strengths in 27Al(p,y) will be discussed, as well as new results from (a,y) reactions taken with the array on A=100 nuclei. Indirect measurements of neutron capture cross sections can be conducted using the surrogate method, where the product of the neutron capture reaction of interest is formed using a more experimentally feasible reaction. Competition between the neutron evaporation and y-decay channels in the compound nucleus is then used as a probe of how that nucleus will behave when it is instead formed by neutron capture. Another alternative to direct measurement is to experimentally constrain (n,y) cross sections using the Oslo method to extract statistical properties from a compound nucleus formed by another, readily accessible reaction channel. These statistical properties can then be used in Hauser-Feshbach calculations to determine (n,y) cross sections. Particle-y coincidence data, which acts as the input for both methods, was taken using the Hyperion detector array at Texas A&M University in collaboration with LLNL. Indirect measurements of 145,146Sm(n,y)146,147Sm and 159,160Dy(n,y)160,161Dy were attempted using (p,d) and (p,t) reactions on self-supporting 148Sm and 162Dy targets. Preliminary results from both methods will be presented, as well as future plans for these analyses.

First I briefly overview the motivations of heavy ion collision experiments in general, both at low and high energies: it is mainly about exploring different parts of the phase diagram of nuclear and hadronic matter. Then I continue with the motivations of recent studies of light nuclei production in ultra-relativistic heavy ion collisions: anti-nuclei in space, and search for the critical point of the strongly-interacting matter. After this I focus on a particular recent development --- the possible solution of the "snowballs in hell" puzzle --- why the nuclei with binding energies of few MeV apparently survive at temperatures of around 155 MeV. Recent simulations using a hydrodynamics + hadronic transport approach, where deuterons are produced and destroyed mainly in pi pn -> pi d reactions show that deuterons do not really survive. They are rather created and disintegrated with approximately equal rates during certain period of time.

The first detection of gravitational waves in 2015 by the Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors, created by the merger of black holes more than a billion years ago, was followed by several other signals from black holes. In 2017, the merger of neutron stars was detected by LIGO and Virgo detectors and by gamma-ray telescopes, and was found by many electromagnetic observations too: a new era of gravitational wave astrophysics has started with very bright prospects for the future. In April 2019, LIGO and Virgo started taking data again, and many more merging black holes and neutron stars have been discovered. We will describe the technology involved in the LIGO gravitational wave detectors, details of the latest discoveries and the exciting prospects for more detections in the next years.

To model the composition of the core of a massive star during its collapse, a treatment of the nuclear statistical equilibrium, starting from a single-nucleus approximation equation of state (Lattimer and Swesty, LS), has been built recently. This allows a more realistic description of the nuclear distribution inside the core and, more specifically, to quantify the role of the nuclear masses. The distributions obtained with the original mass functional (LS) and those obtained with HFB-24 and DZ10 mass models have been compared for several thermodynamic conditions of a typical CCSN trajectory. The differences in the composition could lead up to approximately 25% deviations in the electron-capture rate, thus showing the need to identify a proper mass model to use in CCSN simulations. Therefore, new high precision mass measurements in the nuclear mass region of interest, via a double Penning trap at the IGISOL facility (Jyvaskyla, Finland), were performed. Five new mass excess were determined for the following nuclei : 69m,70Co, 74,75Ni and 76mCu. The precision has been improved for five others : 67Fe, 69Co, 76,78Cu and 79mZn. The experimental values of the nuclear gaps for Z=28 and N=50 have been compared with the results predicted by DZ10 and HFB-24. The latter model better reproduces the evolution of these gaps. Despite the different predictions of DZ10 and HFB-24, a moderated impact of the mass model on the composition of the collapsing core was found after implementing the recent statistical treatment in an existing CCSN hydrodynamical simulation. Moreover, those differences in composition have a small effect on the collapse dynamics, which appears to be more sensitive to the electron-capture model. The latter can be better constrained by means of nuclear charge exchange experiments. The upcoming 14O(d,2He)14N charge exchange experiment using the AT-TPC should demonstrate a very promising way of constraining the electron capture rates of the exotic nuclei capturing the most during the CCSN.

Performers Imjeong Choi (cello) Imjeong Choi is a South Korean cellist. She graduated from Hanyang University in Seoul, South Korea, with a bachelor of music degree, in addition to receiving an education of music degree. In South Korea, Choi worked in Boseong Girl's Middle School as a cello teacher, and completed an internship at Muhak Middle School. She received first prize in the Hanyang Chamber Music Competition, and was a member of the Seoul Metropolitan Youth Orchestra. In the United States, Choi earned her master's degree in cello performance at MSU in 2019. She spent a summer working in the Ohio Light Opera, and she participated in MSU Summer Study Abroad in Todi, Italy, where she held a performance. She also toured Hong Kong, China, the Philippines, Taiwan, and Japan as a member of the Asian Youth Orchestra. Since 2018, Choi has been a member of the Midland Symphony Orchestra. Currently, Choi is pursuing her doctor of musical arts degree in cello performance at MSU, where she studies with Suren Bagratuni. Minhae Lee (piano) Pianist Minhae Lee is the winner of the Chicago North Shore Musicians Club scholarship, the Honors Concerto Competition at Michigan State University (MSU), the New Tang Dynasty Television International Piano Competition, the "Golden Classical Music Awards" International Competition, the Taegu Broadcasting Corporation Daegu Broadcasting Corporation Competition, and the Daejin University Piano Competition. Lee completed her bachelor's and master's degrees from Yonsei University in Seoul. She also attended the Chicago College of Performing Arts at Roosevelt University, and the Manhattan School of Music, where she was awarded a full scholarship to study with Dr. Solomon Mikowsky. As a collaborative pianist, she has held a position of collaborative pianist staff at the Jeju International Brass Competition, Manhattan, in the Mountain Summer Festival, Manhattan School of Music, Michigan State University, and the Aspen Music Summer Festival. Minhae Lee is an adjunct faculty member at Alma College, and is a piano faculty member of the Community Music School at Michigan State University, in addition to giving lessons for the Aspen Music Summer Festival Passes and Lessons Scholarship program. She holds a doctoral degree in piano performance from MSU, where she is currently completing her second doctoral degree in collaborative piano, and her second master's degree in piano pedagogy.

"Nova eruptions powered by shocks" and "Search for 511 KeV gamma-rays from Novae and uncertainty in 18F(p,alpha) reaction rate"

Chirality plays a fundamental role in the Standard Model, where the charged weak current is modeled as purely left handed. Models for new physics naturally break this symmetry, so sensitive searches for chirality-flipping interactions could be a powerful tool for discovery. We will discuss a proposal for a sensitive search for chirality-flipping interactions by measuring the beta spectrum of 6He, 19Ne and 14O. We plan to measure beta energies via cyclotron radiation emission spectroscopy (CRES), recently demonstrated by the Project 8 collaboration, extending its use to the broader range of electron energies of the 6He and other nuclear beta decays. In principle, the method allows determination of the beta energy at its creation. We will also discuss other applications of the technique, including experiments that could be carried out at radioactive beam facilities.

Lattice QCD calculations are the most successful tool to access the dynamics of quarks and gluons at low energies. However, these calculations are computationally challenging, because of the large size of the systems that are usually simulated. We present a new procedure that would allow reduced computational resources to calculate quark propagators and hadronic two-point functions on the lattice. The main tools used are machine learning regression algorithms, which are used to relate propagators obtained with the BiCGStab linear solver with different convergence parameters. A mapping between low precision propagator data to high precision propagators is investigated and assessment of the systematic uncertainty over the gauge field configuration ensemble of the procedure is discussed. The validity of the method is assessed based on derived quantities such as effective masses of hadrons, together with the potential gain in computer time. This new approach to the computing quark propagators could lead to faster calculations of hadronic observables in lattice QCD, but also to faster pseudo-fermions calculations in the Markov-Chain Monte Carlo algorithms to generate lattice gauge field configurations.

In this talk, "Leadership in an Engineering Environment," Trudy Kortes, a 30-year NASA veteran and STEM speaker and consultant, will describe the typical characteristics of an industrial engineering organization, the typical characteristics of engineers, and typical situations you might find yourself in within an engineering organization. She will discuss the hard realities you will face as well as manifestations of each of these topics, and then you will learn strategies, approaches, and coping mechanisms to successfully maneuver yourself through your career. Consider this an investment in your future self.

In this journey we will depart from the often-present science-art dichotomy, exploring the complicated, often-unexpected relationship that physics and the arts share. This complex relationship provides opportunities for fresh storytelling, in particular, physics narratives embedded in a wider culture and interdisciplinary explorations. I will also argue that science acting in concert with the arts can deliver benefits beyond science communication: Addressing questions of social justice as influence for a more equitable world

I discuss a scheme for computing weak decay and capture rates for essentially all nuclei, with or without deformation, even or odd. After presenting recent results and their consequences, I show how we plan to include missing nuclear correlations and so make our methods more accurate.

Theoretical nuclear physics research provides rich problems for machine learning research. This talk will introduce and step through machine learning theory, while highlighting theory projects in collaboration with the Thomas Jefferson National Accelerator Facility, looking towards the future Electron-Ion Collider. Specifically, I will discuss using machine learning to build event generators, to predict theoretical parameters from experimental data, and predicting structure functions for given experimental kinematics. I will highlight areas where current machine learning methods can improve for scientific applications, providing a rich environment for the advancement of both physics and machine learning research.

At the University of Kentucky Accelerator Laboratory (UKAL), we have performed [gamma]-ray spectroscopic studies following inelastic neutron scattering from several candidates for neutrinoless double-beta decay, with our most recent measurements focusing on 76Ge [1] , 136Xe [2], and other nuclei in these regions. The experiments, from which a variety of spectroscopic quantities were extracted, employed solid isotopically enriched scattering samples. From these measurements, low-lying excited states were characterized, 0+ states and their decays were identified, level lifetimes were measured with the Doppler-shift attenuation method, multipole mixing ratios were established, and transition probabilities were determined. The rate of [neutrinoless double-beta decay] is approximately the product of three factors: the known phase-space factor for the emission of the two electrons, the effective Majorana mass of the electron neutrino, and a nuclear matrix element (NME) squared. The NMEs cannot be determined experimentally and, therefore, must be calculated from nuclear structure models. A focus of our recent measurements has been on providing detailed nuclear structure data to guide these model calculations, and a procedure for future work, which will lead to meaningful data for constraining calculations of NMEs, is suggested. This material is based upon work supported by the U.S. National Science Foundation under grant no. PHY-1913028. [1] S. Mukhopadhyay, et al., Phys. Rev. C 95, 014327 (2017). [2] E.E. Peters, et al., Phys. Rev. C 98, 034302 (2018).

The harvesting of rare isotopes at the National Superconducting Cyclotron Laboratory (NSCL) is accomplished by the deposition of heavy ion beams in a water filled beam blocker. With the dissipation of such large amounts of energy, not only a plethora of radionuclides is formed, radiolysis reactions are induced as well. The thereby created various radiolytic products can either react with each other, resulting in mutual annihilation, or escape into the bulk solution. In general, molecular products such as hydrogen peroxide, molecular oxygen and hydrogen exhibit longer life times and could potentially increase to considerable levels in open systems. In order to ensure adequate water conditions for isotope harvesting, knowledge about the behavior of these species is vital. This will become particularly significant when considering the intended utilization of an aqueous beam blocker at the upcoming Facility for Rare Isotope Beams (FRIB). In several experiments at the NSCL the formation of H2O2, H2 and O2 was investigated with 48Ca20+ and 78Kr35+/36+ beams with beam currents from 0.8 to 80 pnA. To mimic the conditions expected at FRIB, the water filled beam blocker was irradiated with a high intensity proton beam (5-50 [microamperes]) for several hours at the Cyclotron Research Laboratory at the University of Wisconsin–Madison. The formation of H2O2, H2 and O2 in the harvesting system’s water was calculated based on the applied beam power; however, the measured levels were considerably lower. Based on these observations, an aqueous phase reaction of hydrogen peroxide and hydrogen is rendered possible. The current model would support the interaction of all radiolytically formed species, even though the volume of irradiated water ([approximately] 35-55 L) was much larger compared to conventional aqueous cyclotron targets.

Coiled finned-tube heat exchangers, also called Collins type heat exchangers, are frequently used in small to medium scale cryogenic systems to improve design packaging (compactness) while maintaining high thermal effectiveness. A typical heat exchanger assembly of this kind consists of an inner cylindrical shell, called the mandrel, with helical finned-tube coils wrapped around it, and then enclosed by an outer shell. The two flow paths are through the helically wrapped tube, and the annular flow around the outside of the tubes. An accurate description of the shell-side thermal-hydraulic flow characteristics is a necessary part of the heat exchanger design. In this paper, these characteristics for cryogenic gaseous nitrogen, between 300 to 100 K, are numerically investigated. A computational fluid dynamics model of the shell-side geometry is developed and validated. Simulations are carried out for a wide range of flow conditions. Data obtained from the numerical simulations are used to form correlations between the shell-side Reynolds number (Re), Fanning friction factor (f), and Chilton-Colburn factor (j). In addition, the effect of geometrical variance on the correlation was investigated. The results from this study show reasonable agreement between the correlations developed numerically and experimental data.

Recent advances in photolithography and micro processing techniques have enabled the emergence of Micro Pattern Gaseous Detectors (MPGDs) such as Gas Electron Multipliers (GEMs) or Micro Mesh Gaseous Structures (Micromegas) or Micro Resistive Well Detectors ([micro]RWELLs). These new technologies combine the gas amplification principle of gaseous detectors with micro-structure printed circuits technologies to provide a wide variety of high rate particle tracking detectors with excellent space and time resolution, high radiation tolerance, low material and large material capabilities. Several technical breakthroughs over the past decade have allowed the possibility for large area MPGDs, making them cost effective and high-performance detector candidates to play pivotal role in current and future nuclear physics (NP) and high energy physics (HEP) experiments. We will give an overview of the state of the art of MPGDs technologies and introduce the RD51 collaboration which is a CERN-based international collaboration dedicated to the development and advancement of the MPGDs technologies for application in current and future large-scale particle physics experiments such as the Electron Ion Collider (EIC) or High Luminosity LHC. Finally, we will conclude with a brief overview of the MPGDs deployed in the various detectors packages of the 12 GeV upgrade of the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson National Lab.

Committee: Hendrik Schatz(Chairperson), Edward Brown, Michael Murillo, Witold Nazarewicz, Artemis Spyrou

The exponential growth of Hilbert space with system size is one of the fundamental challenges in many-body physics. Consequently, existing computational methods rely on making clever approximations to reduce the problem to a more tractable form. The machine learning community often encounters a similar challenge, the so-called "curse of dimensionality," in which data sets become exponentially more sparse as the dimension increases. Overcoming this curse has propelled progress in machine learning for decades and has been made possible by the underlying structure in many real data sets. In this talk, I will share a few different ways machine learning techniques can build upon current many-body methods to improve their flexibility and circumvent exponential scaling. In particular, shallow neural networks are used as trial wave functions for Variational Monte Carlo (VMC) and recurrent neural networks are used to predict the ground state from In-Medium Similarity Renormalization Group (IMSRG) calculations.

The Standard Model of Particle Physics (SM) has been widely successful in describing the measured particle spectrum and composition of matter ranging from quarks and gluons to multi-hadron systems. Such systems constitute approximately 5% of the observable matter-energy within the Universe. Yet the theory alone cannot explain the origins of the remaining 95% of matter and energy, dubbed "Dark Matter" and "Dark Energy", respectively. Further, the Standard Model does not provide the requisite amount of CP violation to account for the observed matter-antimatter asymmetry. Therefore any physical description of such phenomena requires a theory that goes beyond the Standard Model (BSM), while at the same time encompassing the Standard Model and its predictions related to ordinary matter. The electric dipole moments (EDM) of the nucleon is a very sensitive probe of CP violation and the current bound on the neutron EDM strongly constrains many BSM physics scenarios. The considerable challenges presented by the calculation of the nucleon EDM from Lattice QCD can only be addressed combining Exascale computing capacities with the development of new algorithms, and new theoretical and numerical techniques. I will present our Lattice QCD results of the first determination of the theta-term contribution to the nucleon EDM and towards a complete determination of all the CP-violating contributions to the nucleon EDM. I will emphasize the role played by a novel theoretical tool, the Gradient Flow, and by a novel noise reduction technique we recently introduced. I will also present our new algorithmic developments based on Machine Learning techniques and the perspective for lattice QCD calculations using Quantum Computers.

Neutron detectors for fast neutron detection (i.e. in the energy range from tens of MeV to hundreds of MeV) are part of a number of set ups at rare isotope facilities in the world, and MoNA, the modular neutron array is one of them. Since MoNA has seen its first beam in 2003, newer detectors have come online at RIKEN and GSI, but the basic concept stays the same. This research discussion will address the question of how a next generation neutron detector could look like. A brief overview of the neutron detector’s performance parameters, like position and energy resolution, detection efficiency, and size requirements for the specific application of detecting fast breakup neutrons for the invariant mass reconstruction of unbound states, will be given. What new technologies could be utilized for a new neutron detector? Some ideas will be presented.

Direct reactions at energies of a few MeV per nucleon above the Coulomb barrier are a powerful tool for probing nuclear structure. In inverse kinematics, a necessity for such studies with radioactive ion beams, the spectrum of outgoing ions suffers at significant compression at forward center-of-mass angles. The use of a solenoidal spectrometer removes this artifact of the kinematics, allowing for reaction studies with good resolution. This technology was pioneering at Argonne National Laboratory with the development of HELIOS. It inspired the implementation of the ISOLDE Solenoidal Spectrometer (ISS) at CERN and plans for a next-generation device at ReA, called SOLARIS. The advantages of this technique will be discussed along with a physics highlights from HELIOS and the ISS, including the recent work reporting on the exploration of a previously uncharted region of the nuclear landscape beyond the closed neutron shell of N = 126. An overview of plans for the use of SOLARIS in the ReA standalone period, and beyond, will be given.

Tracking charged particles through magnetic fields is often an arduous, time-consuming process in experimental analysis. In a recent Hack-a-Thon, presented by Jefferson Lab as a part of their AI for Nuclear Physics Workshop, this problem was tackled using machine learning. Multiple neural-network based methods for the reconstruction of the path of a charged particle through a drift chamber with varying levels of complexity are presented here.

COMMITTEE: Peter Ostroumov(Chairperson), Thomas R. Bieler, Phillip M. Duxbury, Steven Lidia, Kenji Saito

iThemba LABS has embarked on an extensive renewal program with the ultimate goal to provide the users with competitive and state-of-the air research facilities for nuclear physics experiments. In particular, significant developments on the high-energy neutron beam facility, the K600 magnetic spectrometer and the ALBA (large-volume LaBr3:Ce detectors) and AFRODITE (HPGe Clover+BGO detectors) gamma-ray arrays have taken place. These are anticipated to greatly improve and make possible new measurements of nuclear properties which are of relevance to nucleosynthesis. For instance, the development of the inverse-Oslo method [1] at iThemba LABS to extract the photon strength function (PSF) and nuclear level density (NLD) from inverse kinematic reactions provides a complementary tool to the beta-Oslo Method [2] to study statistical properties for a wide range of nuclei, which were previously inaccessible at stable or radioactive ion beam facilities. Several such inverse kinematic PSF and NLD measurements have already been performed at iThemba LABS and HIE-ISOLDE at CERN. Furthermore, measurements of the PSF and NLD at the University of Oslo have recently provided new constraints on the production of the p-nuclei 138La [3] and 180Ta [4]. In this presentation, I will provide a brief overview of our experimental capabilities at iThemba LABS, in particular in the context of ongoing and future measurements to obtain PSF, NLD and resonance data which are of importance to nucleosynthesis studies. I will further introduce the concept of PSF and highlight its relevance to nuclear structure and astrophysics before discussing our work on PSFs of the 138La and 180Ta p-nuclei and how these are used to constrain reaction rates at p- and s-process temperatures. [1] VW Ingeberg et al., Eur. Phys. J. A 56, 68 (2020). [2] A Spyrou et al., Phys. Rev. Lett. 113, 232502 (2014). [3] BV Kheswa et al., Phys. Lett. B 744, 268 (2015). [4] KL Malatji et al., Phys. Lett. B 791, 403 (2019). This work is supported by the National Research Foundation of South Africa under grant number 118840 and the IAEA under contract 20454.

Uncertainty Quantification (UQ) is an instrumental tool in assessing how accurately a mathematical model describes a true physical process. The statistical tools of UQ have been effective in enhancing the quality of models in many ways. First, they can be used to understand a model's structure through parameter estimation, correlation analysis, and model reduction. Second, they can improve predictive capability and asses the information content of models with respect to measured observables. In this talk, I will demonstrate the opportunities in nuclear theory offered by various statistical methods and diagnostic tools, including Bayesian calibration, Bayesian model averaging, chi-square correlation analysis, principal component analysis, and empirical coverage probability. These tools will be illustrated on the 4-parameter Liquid Drop Model informed by measured masses of even-even nuclei over discrepant mass domains. Finally, I will show how principal component analysis can lead to quite a significant parameter reduction of the 14-parameter realistic Skyrme energy density functional.

Committee: Luke Roberts (Chairperson), Sean Couch Brian O’Shea, Jaideep Singh, Heiko Hergert

COMMITTEE: Alexandra Gade (Chairperson),Daniel Bazin, B. Alex Brown, Wade Fisher, Sean Liddick. Thesis is available at https://pa.msu.edu/academics/graduate-program/current-graduate-students/ - select student name

Committee: Peter Ostroumov (Co-chairperson), Sergey Baryshev (Co-chairperson), Prem Cahahal, Timothy Grotjohn, Yue Hao, John Verboncoeur

NICER, the Neutron Star Interior Composition Explorer, is an X-ray telescope that was installed on the International Space Station in 2017. Its mission is to study the nature of the densest matter in the Universe, found in the cores of neutron stars. NICER uses Pulse Profile Modeling, a technique that exploits relativistic effects on X-rays emitted from the hot magnetic polar caps of millisecond pulsars. The technique also lets us map the hot emitting regions, which form as magnetospheric particles slam into the stellar surface. I will present NICER's first results and discuss the implications for our understanding of ultradense matter, pulsar emission, and stellar magnetic fields. I will also discuss how NICER is paving the way for the next generation of large-area X-ray timing missions like eXTP and STROBE-X.

Committee: Heiko Hergert (Chairperson), Alexei Bazavov, Scott Bogner, Matthew Hirn, Jaideep Singh

The search for sterile neutrinos is among the brightest possibilities in our quest for understanding the microscopic nature of dark matter in our universe. Sterile neutrinos - unlike the active neutrinos in the Standard Model (SM) - do not interact with normal matter as they move through space, and are thus best observed via their mass-generated effects that result from momentum conservation with SM particles. One way to observe these momentum recoil effects experimentally is through high-precision measurements of electron-capture (EC) nuclear decay, where the final state only contains the neutrino and a recoiling atom. This approach is a powerful method for neutrino mass studies since it relies only on the existence of a heavy neutrino admixture to the active neutrinos, which is a generic feature of neutrino mass mechanisms, and not on the model-dependent details of their interactions. In this talk, I will discuss our first measurements in the Beryllium EC STJ (BeEST) experimental program, which uses the decay-momentum reconstruction technique to precisely measure the 7Li recoil spectrum following the EC decay of 7Be implanted into sensitive superconducting tunnel junction (STJ) radiation detectors.

Committee: Filomena Nunes(Chairperson), B.Alex Brown, Laura Chomiuk, Pawel Danielewicz, Remco Zegers

Quantum computers have the capability of manipulating the state of a quantum system by applying some general unitary transformations. In what is currently accepted universal scheme these transformations are reconstructed exploiting the Solovay-Kitaev theorem, that is using a small set of transformations (the so-called quantum gates). There is an alternative strategy, though. It considers the possibility of exactly implementing a generic unitary transformation by explicit construction. This is the so-called optimal control approach. In this talk I will show how optimal control can be effectively used on Circuit-QED based machines. Moreover, I will present an application to the study of the spin dynamics of two neutrons interacting with a simple EFT potential at LO. This study opens the door to a direct computational implementation of the time evolution of quantum states, which has a potential immediate application in the realistic simulation of generic nuclear reactions.

Committee: Steven Lund (Chairperson), Yue Hao, Dean Lee, Steven Lidia, Chong-Yu Ruan

Parton distribution functions (PDFs) encode the non-perturbative structure of hadrons and their knowledge is essential for our ability to predict experimentally measured cross sections. They play an important role in discovering new physics at high energy collider experiments as well as in our understanding of the internal structure of hadrons. However, up until recently, PDFs could only be determined from experimental data while first principles theoretical computations were not possible. Novel ideas that came along have opened new avenues for ab initio parton distribution function computations. In this talk, I am presenting the basic ideas that are underlying these computations and review recent numerical results. Furthermore, I am discussing the future of such computations and their potential impact to phenomenology.

The ISOLDE Facility at CERN is the worlds leading facility for the production of radioactive ion beams using the ISOL (Isotope Separation On-Line) method. Over 1000 isotopes and isomers of more than 70 elements have been produced by the impact of a 1.4 GeV proton beam on a variety of targets and using different ion sources for providing beams at 40-50 keV energy. Beam purification is achieved through the use of the selective resonance laser ionization process in more than half of the experiments and by mass separation using one of two mass separators. The isotope/isomer beams can be further accelerated to about 10 MeV/u using the HIE-ISOLDE post-accelerator. The low-energy and accelerated beams are used for a wide variety of experiments in nuclear structure research, but also for studying astrophysical processes, for materials properties research, for biochemical and biomedical research and for fundamental interaction studies. This presentation will give an overview of the many physics questions addressed by the wide variety of ISOLDE experimental set-up, with recent examples in different fields of research.

Committee: Jaideep Singh (Chairperson), Tyler Cocker, Yue Hao, Heiko Hergert, Kei Minamisono

Committee: Filomena Nunes (Chairperson), Scott Bogner, Kaitlin Cook, Pawel Danielewicz, Kendall Mahn

The TALENT initiative, Training in Advanced Low Energy Nuclear Theory, aims at providing advanced and comprehensive training to graduate students and young researchers in all aspects of low-energy nuclear theory. TALENT offers intensive three-week courses on a rotating set of topics. General information on TALENT and past courses can be found at http://www.nucleartalent.org. This year, due to the COVID-19 pandemic we offer a fully online variant of the course on: Machine Learning and Data Analysis for Nuclear Physics It will be held via the ECT* in Trento, Italy, from June 22 to July 3, 2020. The principal instructors will be 1. Daniel Bazin (MSU/NSCL/FRIB), 2. Morten Hjorth-Jensen (MSU/NSCL/FRIB), 3. Michelle Kuchera (Davidson College), 4. Sean Liddick (MSU/NSCL/FRIB), and 5. Raghuram Ramanujan (Davidson College). Videos of the learning material, programs, and all digital learning material will be made available to participants before the lectures start in a dedicated Classroom on Microsoft Teams. During the week of June 22-26 and June 29 to July 3, we will have online live lecture sessions from 2 pm to 4 pm Central European Time (CET), with questions and answers sessions from 5 pm to 6 pm CET. The standard variant of this course, with in-person attendance, is postponed to the summer of 2021. For applications and more information for the online TALENT course, please go to the website of the European Center for Theoretical Studies in Nuclear Physics and Related Areas, ECT*. The link with more information and registration is at https://www.ectstar.eu/node/4472 All material with schedule etc. will be available at https://github.com/NuclearTalent/MachineLearningECT For more information: Contact: Morten Hjorth-Jensen (hjensen@msu.edu)

Hosts: Jutta Escher, Kristina Launey and Filomena Nunes Panelists: Cedric Simenel and Kaitlin Cook

A significant fraction of stars between 7 and 11 solar masses are thought to become supernovae, but the explosion mechanism is unclear. Does the star collapse to a neutron star, or is it disrupted by a thermonuclear explosion? As it turns out, the answer depends critically on a small number of electron-capture reactions that take place in the star's degenerate oxygen-neon core. Of particular interest are the electron captures on 20Ne, which trigger the explosive burning of oxygen. In this webinar, I will review our current understanding of the final evolution of intermediate-mass stars, focusing on the important role played by the electron-capture reactions. I will discuss recent progress made in constraining the all-important electron-capture rate on 20Ne, clarify the astrophysical implications, and identify remaining gaps in our knowledge.

The school will focus on dense matter in astrophysics, such as the matter in the interior of neutron stars and the one created in supernova explosions and neutron star mergers, along with comparisons with the matter created in laboratories. There will be lectures from the following experts, together with interactive activities.

Carbon burning powers the final millennia of a massive star's life. Type Ia supernovae, the thermonuclear explosions of white dwarf stars and cosmology's standard candles, are ignited by thermally unstable carbon burning. In the deep ocean of accreting neutron stars, unstable carbon burning powers rare, energetic superbursts that take the neutron star's core temperature. This introductory talk will present these three phenomena and their dependence on the carbon burning cross section at low energies.

A new direct measurement of the 12C+12C fusion reaction has been performed down to the energy regime relevant to carbon burning in massive stars by the STELLA collaboration [1]. Specificities of the STELLA setup will be presented as well as the analysis techniques and the results down to astrophysical energies. Results span over eight orders of magnitude and support the fusion-hindrance model, which will be discussed in the light of deep sub-barrier fusion measurements for other systems and general behavior of the nuclear matter.

A new measurement of 12C+12C reaction has been performed at the University of Notre Dame using particle-[gamma] coincidence techniques with SAND (a silicon detector array) at the high-intensity 5U Pelletron accelerator. A differential thick target approach was applied to obtain reliable carbon fusion cross sections down to astrophysical energies. Our new results show strong disagreement with a recent measurement using the indirect Trojan Horse method.

Committee: Dean Lee (Chairperson), Morten Hjorth-Jensen, Mohammad Maghrebi, Andrea Shindler, Andreas von Manteuffel

Please join us on July 8th 2020 from 1:00-3:00 EDT for an online symposium to honor the late pioneer Eleanor Margaret Burbidge. This event will celebrate her life and science through short talks from her colleagues and collaborators as well as researchers who have benefited from her trailblazing and scientific insights.

Fission studies using multi-nucleon transfer (MNT) reactions [1,2] at the tandem facility of Japan Atomic Energy Agency (JAEA) in Tokai, Japan, will be presented. The MNT reaction allows us to produce neutron-rich actinide nuclei, which cannot be populated by particle capture reactions. Taking advantage of many MNT channels opened in the 18O induced reactions, fission fragment mass distributions (FFMDs) for various actinide nuclei can be obtained in one reaction. Many data were accumulated using various actinide-targets nucleus, including 232Th, 238U, 237Np, 243Am, and 248Cm. The FFMDs at higher excitation energies are explained only by invoking a concept of multichance fission, i.e. neutron-evaporation before fission [3]. Also, fission barrier height was derived by finding the excitation energy of the compound nucleus that fission probability starts to appear [4]. The obtained data set was used to improve the Langevin model to describe low-energy fissions,which resulted in a clear explanation of the transition from the mass-asymmetric ssion to the sharp symmetric ssion observed in the fermium isotopes [5]. Recently, we obtained the 254Es target material from Oak Ridge National Laboratory, US, to promote experiments on low-energy ssions in the neutron-rich fermium region. The results will be presented. [1] R. Leguillon et al., Phys. Lett. B 761, 125 (2016). [2] K. Hirose et al., Phys. Rev. Lett. 119, 222501 (2017). [3] S. Tanaka et al., Phys. Rev. C 100, 064604 (2019). [4] K.R. Kean et al., 100, 014611 (2019). [5] Y. Miyamoto et al., Phys. Rev. C 99, 051601(R) (2019).

Committee: Witold Nazarewicz(Chairperson), H. Metin Aktulga, Morten Hjorth-Jensen, Hironori Iwasaki, Filomena Nunes, Brian O'Shea

Hosts: Baha Balantekin and Vincenzo Cirigliano

Committee: Witold Nazarewicz (Chairperson), Scott Bogner, Sean Couch, Kendall Mahn, Jaideep Singh. Thesis is available at https://pa.msu.edu/academics/graduate-program/current-graduate-students/ - Select student name

In this seminar I will present some of our later results on the 213Pb neutron-rich nucleus studied using the unique availability of a primary 1 GeV A 238U beam and of the FRS-RISING setup at GSI. The products of the uranium fragmentation were separated in mass and atomic number and then implanted for isomer decay [gamma]-ray spectroscopy. A level scheme from the decay of the spin and parity 21/2+ isomer, based on [gamma] intensities, [gamma]-[gamma] coincidences and state lifetimes was built up and the E2 transition probabilities from the spin and parity 21/2+ isomer to two low-lying spin and parity17/2+ levels were also deduced. This experimental data has evidenced one of the best examples of a semi-magic nucleus with a half-filled isolated single-j shell where seniority selection rules are obeyed to a very good approximation. In the most simple shell-model approach 213Pb can be described as five neutrons in the orbital g9/2 on top of the 208Pb core. Large scale shell-model calculations in the full valence space beyond 208Pb confirm that although the orbital g9/2 is not isolated in energy, it is found to carry the dominant component in the wave function of the low-energy states. The experimental level scheme and the reduced transition probabilities are in good agreement with the theoretical description that predicts the existence of two spin and parity 17/2+ levels of a very different nature: one with seniority 3, while the other with seniority 5. The absence of mixing between the two spin and parity 17/2+ states follows from the self-conjugate character of 213Pb, where the particle-hole transformation defines an observable Berry phase that leads to the conservation of seniority for most but not all states in this nucleus. The Berry phase [1], which is a gauge-invariant geometrical phase accumulated by the wavefunction along a closed path, is a class of observables that are not associated with any operator. It is a key feature in quantum-mechanical systems, that has far reaching consequences, and has been found in many fields of physics since its postulation in the eighties. In the atomic self-conjugate nucleus 213Pb, the quantized Berry phase is evidenced by the conservation of seniority under the particle-hole conjugation transformation. In atomic nuclei no experimental signature of the Berry phase was reported up to now. [1] M. V. Berry, Proc. Roy. Soc. A392, 45 (1984).

Committee: Pawel Danielewicz (Chairperson), Morten Hjorth-Jensen, Filomena Nunes, Carlo Piermarocchi, Man-Yee Betty Tsang, Gary Westfall. Thesis is available for review at https://pa.msu.edu/academics/graduate-program/current-graduate-students/ - Select student name

Quantum computing is an emerging computational paradigm that has the potential to solve the quantum many-body problem more successfully than classical computing does. However, many quantum algorithms that attempt to reconstruct wave functions have low fidelity and are not robust against noise. To this end, the projected cooling algorithm has emerged as a promising algorithm that reconstructs the localized ground state of any Hamiltonian with a translationally-invariant kinetic energy and interactions that vanish at large distances. Projected cooling yields a significant improvement over previous quantum algorithms such as quantum adiabatic evolution. However, the projected cooling algorithm has been limited to Hamiltonians whose ground state is localized, which reduces its applicability in many-body systems. We introduce a new form of the projected cooling algorithm that is able to reconstruct the ground state of any general Hamiltonian while maintaining the accuracy of the original projected cooling algorithm. The generalized projected cooling algorithm can be applied to a wide range of many-body systems, particularly in nuclear physics.

One of the major issues in modern astrophysics concerns the analysis and understanding of the present composition of the Universe and its various constituting objects. Nucleosynthesis models aim to explain the origin of the different nuclei observed in nature by identifying the possible processes able to synthesize them. Though the origin of most of the nuclides lighter than iron through the various hydrostatic and explosive burning stages in stars is now quite well understood, the synthesis of the heavy elements (i.e. heavier than iron) remains obscure in many respects. In particular, the rapid neutron-capture process, or r-process, is known to be of fundamental importance for explaining the origin of approximately half of the A>60 stable nuclei observed in nature. The r-process was believed for long to develop during the explosion of a star as a type II supernova but recent observations tend to favour the merging of two compact objects. The recent observation of the binary neutron star (NS) merger GW170817 and its corresponding optical kilonova counterpart suggest that neutron star mergers are the dominant source of r-process production in the Universe. Comprehensive nucleosynthesis calculations based on sophisticated multidimensional relativistic simulations show that the combined contributions from both the dynamical (prompt) ejecta expelled during NS-NS or NS-black hole (BH) mergers, and the neutrino and viscously driven outflows generated during the post-merger remnant evolution of relic neutron stars or BH-torus systems can lead to the production of r-process elements from Zr (A > 90) up to thorium and uranium with an abundance distribution that reproduces extremely well the solar distribution, as well as the elemental distribution observed in low-metallicity stars. The stellar nucleosynthesis requires a detailed knowledge not only of the astrophysical sites and physical conditions in which the processes take place, but also the nuclear structure and interaction properties for all the nuclei involved. Both the astrophysical and nuclear physics aspects of the r-process nucleosynthesis in neutron star mergers will be discussed with a special attention paid to major open questions affecting our understanding of the r-process nucleosynthesis.

Abstract: The chemical composition of the Universe is continuously evolving. Since the Big Bang nucleosynthesis, which only produced hydrogen, helium, and lithium, countless number of astrophysical events such as supernova explosions and neutron star mergers have enriched galaxies with heavier elements. Studying the chemical evolution of galaxies represents a significant challenge because of the wide range of physical processes that occur from nuclear to galactic scales. My expertise lies in the field of galaxy simulations, but my research program lives at the interface between nuclear physics, nucleosynthesis, stellar evolution, and galaxy evolution, and connects to the era of multi-messenger astronomy by combining constraints from gravitational waves, stellar spectroscopy, and meteorites. How can we use this framework to better understand the origin of the elements and isotopes in the Universe? What are the different astrophysical sites that contributed to the chemical composition we see today? In this online seminar, I will explain why multi-disciplinary connections are necessary to answer these questions, and show the importance of nuclear astrophysics when interpreting astronomical observations.

Committee: Dean Lee (Chairperson), Morten Hjorth-Jensen, Mohammad Maghrebi, Kei Minamisono, Daniel Stump

Hosts: Alex Gade, Charlotte Elster, Sanjay Reddy, Jorge Piekarewicz

A long sought-for goal using chemical abundance patterns derived from metal-poor stars is to understand the chemical evolution of the Galaxy and to pin down the nature of the First Stars (POP III). Metal-poor, old, unevolved stars are excellent tracers as they preserve the abundance pattern of the gas they were born from, and hence they are frequently targeted in chemical tagging studies. Here we use a sample of 14 metal-poor stars observed with the high-resolution spectrograph PEPSI at the Large Binocular Telescope (LBT), to derive abundances of 32 elements (34 including upper limits). In this talk I present well-sampled abundance patterns for all stars obtained using local thermodynamic equilibrium (LTE) radiative transfer codes and one-dimensional (1D) hydrostatic model atmospheres. However, it is currently well-known that the assumptions of 1D and LTE may hide several issues, thereby introducing biases in our interpretation in the nature of the first stars and the chemical evolution of the Galaxy. Hence, we use non-LTE (NLTE) and correct the abundances using three-dimensional (3D) model atmospheres to present a physically more reliable pattern. In order to infer the nature of the First Stars, we compare unevolved cool stars, which have been enriched by a single event (``mono-enriched''), with a set of yield predictions to pin down the mass and energy of the POP III progenitor. To date only few bona fide second generation stars that are mono-enriched are known. A simple chi^2-fit may bias our inferred mass and energy just as much as the simple 1D LTE abundance pattern, and we therefore pursue with an improved fitting technique considering dilution and mixing. Our sample presents Carbon Enhanced Metal-Poor (CEMP) stars some of which are promising bona fide second generation (mono-enriched) stars. Finally, we explore the predominant donor and formation site of the rapid and slow neutron-capture elements.

Committee: William Lynch (Chairperson), Man-Yee Betty Tsang, Pawel Danielewicz, Wade Fisher, Vladimir Zelevinsky

Scientific discoveries have historically been rooted in the desire for some to take on a quest to tackle the unknown, often with relentless commitments and efforts. Failures along the way become learning outcomes that eventually shape the directions of the processes leading to solutions. We learn early on that the two camps in science, theorists and experimentalists, not only work in teams but also interact with each other to discuss and brainstorm ideas and pathways to establish meaningful information for the scientific community and the public at large. This relationship/collaboration can only occur if both sides listen carefully, process, and understand the information shared, and then implement the appropriate actions. My journey in becoming a physicist was mirrored after many similar statements while enduring yet unknown but interesting challenges within and outside the physics community. This talk will provide some personal perspectives in becoming a physicist while belonging to an untapped and hidden pool of talented individuals.

Committee: Yoshishige Yamazaki (Co-Chairperson), Guillaume Machicoane (Co-Chairperson), Kirsten Tollefson, Steven Lidia, John Verboncoeur.

Committee: Kenji Saito (Chairperson), Steven Lund, Johannes Pollanen, Jie Wei, Yoshishige Yamazaki

Committee: Remco Zegers (Chairperson), B. Alex Brown, Daniel Hayden, Artemis Syprou, Nathan Whitehorn

Hosts: Dean Lee and Thomas Papenbrock, Panelists: Gaute Hagen and Saori Pastore

Committee: Remco Zeger (Chairperson), Marcos Caballero, Tyce DeYoung, Paul Gueye, Filomena Nunes

Hosts: Dick Furnstahl and Augusto Macchiavelli Panelists: Scott Bogner, Alex Gade

Zoom Link: https://msu.zoom.us/j/93420487130 Ab initio nuclear structure calculations that compute nuclear static properties based on underlying NN interactions and three-nucleon forces have now progressed to studying medium-mass nuclei. However, first-principle calculations for nuclear scattering/reactions are still limited to light systems. A method suitable for heavier nuclei would be very valuable in studying scattering/reactions with astrophysical relevance and for the success of the coming FRIB program that will focus on unstable nuclei near drip lines. In this talk, I will present my recent development of such a method (2004.13575 and 1905.05275). It is similar in spirit to the so-called Luscher method, used in Lattice QCD for computing hadronic scattering. The key idea is a computational experiment: realizing the trapping of nucleus-nucleus or nucleus-nucleon systems in harmonic potential well within the ab initio spectrum calculations, and then extracting scattering information from the output. I will discuss the formalism and report encouraging results from my collaboration with ab initio groups on computing neutron--alpha and neutron--Oxygen-24 scattering phase shifts. I will also discuss ways to generalize this approach to the case of inelastic reactions and three-cluster systems, including the one opened up by our recently developed emulator (2007.03635) for scattering.

Ab initio theoretical nuclear structure calculations including chiral two- and three-nucleon interactions have been very successful in predicting nuclear properties measured at radioactive ion beam facilities. The in-medium similarity renormalization group (IMSRG) is one of these ab initio methods. In the valence-space (VS) formulation, the VS-IMSRG provides from first principles effective Hamiltonians that can be handled with standard nuclear shell model techniques. This framework, therefore, is ideal to cover a wide range of medium-mass to heavy nuclei that can be studied with the shell model. In this seminar I will present recent VS-IMSRG developments leading to calculations for exotic argon, titanium, nickel and tin isotopes, as well as electromagnetic transitions. I will confront theoretical predictions with recent experiments performed at NSCL, RIBF, GANIL and ISOLDE. In addition, the VS-IMSRG can be extended to weak decays. I will discuss VS-IMSRG beta-decay calculations, where recent work shows that the "quenching" needed by conventional approaches to reproduce experimental Gamow-Teller half-lives is mostly avoided when complex nuclear correlations and meson-exchange currents are taken into account. Finally, I will also present some results on the very rare double-beta decays, including a possible connection to electromagnetic transitions.

Nb3Sn, currently the second most-widely used superconductor (second only to NbTi), has important applications in the building of high-field magnets (typically above 10 T) for nuclear magnetic resonance (NMR) devices, particle accelerators, experimental thermonuclear fusion reactors, and other research-use magnets. Nb3Sn is the superconductor of choice to build accelerator magnets for the planned Future Circular Collider (FCC), as the successor to the Large Hadron Collider (LHC). However, the critical current density (Jc - the most important performance index of superconductors - of the state-of-the-art Nb3Sn, which has been at a plateau for nearly two decades, is significantly below that required by the FCC specification at 16 T. On the other hand, a new type of Nb3Sn superconductor we are developing based on the internal oxidation technology, which introduces oxide nanoprecipitates as artificial pinning centers (APC) to Nb3Sn, has demonstrated significantly superior performance to state-of-the-art Nb3Sn, including doubling the Jc at high fields (16 T and above) while significantly reducing the undesirable magnetization at low fields (3 T and below). This talk will discuss the applications of Nb3Sn superconductors in accelerator magnets, their current status, the prospect for a new generation of Nb3Sn superconductors based on the APC technology, and why such conductors, if successful, can be a game changer for future energy-frontier circular colliders.

Hosts: Dick Furnstahl, Augusto Macchiavelli Panelists: Stefanos Paschalis, Wim Dickhoff

The proton radius puzzle continues to be controversially discussed despite recent new developments. It has intersections with the nucleon form factor program and aspects of the electromagnetic probe itself, such as two-photon exchange and lepton universality. I will review the current status and some explicit experimental efforts to expand the full picture and its implications, as a prerequisite for a possible resolution.

Detection of fast neutrons using plastic scintillator provides a valuable tool for the study of neutron- unbound nuclear states at or beyond the dripline. The upcoming FRIB facility will enable experiments to explore neutron-unbound states much farther up the neutron dripline, and to explore multi-neutron decay systems in higher mass regions. Two current goals for the MoNA Collaboration are 1) to design and ultimately construct the next generation neutron detector array for use in the upcoming FRIB HRS hall, and 2) to improve our ability to detect and filter multi-neutron decay events with high efficiency. To this end we conducted an experiment at the LANSCE facility at Los Alamos National Lab using 16 MoNA detector bars to observe in better detail how neutrons scatter in the scintillator volume. Results revealed some disparities in Monte Carlo predictions, especially at higher FRIB energies. Along with recent measurements of detector waveform non-linearities, these observations provide helpful input into the design of the next generation HRS array. We have also developed, based in part on these observations, a neutron hit-pattern algorithm to optimize our multi-neutron detection capability. Results from these studies, and a few ideas for next generation designs, will be presented.

I will talk about the wide range of accelerator R&D going on at Argonne National Laboratory. The main activity is the design and construction of a new 6 GeV electron storage ring that will replace the existing Advanced Photon Source (APS) storage ring. When commissioning finishes, planned for 2023, the APS Upgrade will be the world's brightest storage ring light source. We are currently engaged in several studies to understand the challenges of very low emittance electron beams. Argonne is also deeply engaged in physics and technology of future light sources. I will touch on activities such as superconducting undulators, low emittance electron sources, x-ray free electron laser oscillators as well a future beam wakefield driven accelerators.

Abstract: Astronomical observations of neutron stars inform our understanding of matter at the highest densities. Already, we have used the gravitational-wave data of GW170817 - the first signal from merging neutron stars - to constrain the equation of state of dense matter in neutron stars. More recently, the new heavy neutron-star merger GW190425 has indicated that the gravitational-wave population may include heavier stars not previously observed as galactic binaries. As the mass of the components increases, higher densities of neutron-star matter play a role in the orbital dynamics. I will discuss current methods being used to explore the effect of tidal interactions on the neutron-star coalescence and then translating tidal information from the signal into matter properties in the component stars. I will discuss how these results fit with other neutron-star observations, outline prospects of learning about matter in the current Advanced-detector era, and extrapolate to the potential next-generation gravitational-wave observatories have to map the phase diagram of dense neutron-rich matter. Webinar ID 94652806680 (Fission20)

Besides being Canada's particle accelerator centre with emphasis on nuclear, particle and accelerator physics, TRIUMF has a long history of medical isotope production and radiotherapy. Cancer treatment with different particles has been a long-standing commitment at TRIUMF, first with pion therapy and then with proton therapy, for many years operating Canada's only proton therapy facility. To improve treatment further, we are researching and establishing FLASH radiotherapy, where the total treatment dose is delivered in less than a second. In addition, we are investigating using alpha and auger emitters for targeted radioisotope therapy. Both have the potential to revolutionize cancer treatment by increasing the therapeutic index.

Committee: Man-Yee Betty Tsang (chairperson), Pawel Danielewicz, Mark Dykman, Morten Hjorth-Jesen, William G. Lynch

About half of the heavy elements in our Universe are synthesized by one process, the rapid neutron capture process (r-process). This process requires extreme and violent environments that achieve the necessary neutron-rich conditions. Neutron star mergers and magneto rotational driven supernovae are promising candidates to host the r-process. We investigate the r-process from an observational as well as a nucleosynthesis point of view. Our ultimate goal is to find out indications in favor of, or against neutron star mergers being the proposed only source of r-process elements. Therefore, we are particularly interested in the chemical evolution of heavy elements. Stars that are embedded in the environment of dwarf galaxies provide a perfect stellar laboratory, since they are usually well separated and shielded from external pollution and each galaxy has its own chemical history. We study 380 stars from 13 dwarf galaxies and derive abundances for 12 elements. To learn about the enrichment in heavy elements of dwarf galaxies, we first examine their individual chemical histories to ultimately learn about the heavy element enrichment of dwarf galaxies. Events that may fulfill all found abundance trends are magneto rotational driven supernovae. We use a modern state of the art hydrodynamical simulation to investigate the synthesis of elements in this type of event. In total, we calculate the nucleosynthesis of four models with different magnetic field strengths and rotation rates. We find elements up to xenon (second r-process peak) for the model with weakest magnetic field strength, which is caused by a late change of the proto-neutron star morphology. For the model with the strongest magnetic field strength, we find a fully operating r-process. Having a detailed abundance pattern of this event calculated, we discuss possible observables.

As part of the Nova upgrades in 2012, the Recycler was repurposed as a proton stacker for the Main Injector with the aim to deliver 700 kW. Since January 2017, this design power has been run routinely. Looking towards PIP-II, the Recycler and Main Injector will be required to stack and accelerate 50% more beam in order to deliver 1.2 MW beam power for LBNF/DUNE. This intensity increase poses serious challenges of which some will be discussed, such as space charge tune shifts during slip-stacking, transition crossing in the Main Injector and instabilities in both machines. Different schemes to mitigate these issues, such as resonance compensation and a gamma-t jump system will be discussed.

Studying nature directly from fundamental degrees of freedom is often computationally limited by physical characteristics of exponentially growing configuration (Hilbert) spaces with particle number and signal-to-noise problems. This leaves many systems of interest to nuclear and particle physics intractable for known algorithms with current and foreseeable classical computational resources. By leveraging their natural capacity to describe entangled many-body states, the use of quantum systems themselves to form a computational framework is envisioned to be advantageous. In this talk, I will share a developing perspective on the entanglement structure of quantum fields and discuss implications for their efficient simulation on quantum computational architectures. Webinar ID 94652806680 (Fission20)

In this talk I will describe social science research findings regarding the experiences of White women and underrepresented racial/ethnic minority (URM) people in Science, Technology, Engineering, and Mathematics (STEM) fields. Experimental research on implicit bias and stereotype threat has revealed the powerful influence of negative stereotypes on women and URM people in STEM. This work reveals differential evaluation of women vs. men and majority vs. URM groups, and also shows the influence of a more 'chilly' or negative climate for members of groups targeted by stereotypes purporting they are less suitable for STEM. I will also discuss some recommendations for institutional change that can help create a more inclusive and equitable environment for all.

Nuclear [beta] decay has a long-standing history of shaping and testing the standard model of particle physics, and it continues to this day with elegant, ultra-precise low-energy nuclear measurements. Experiments observing the angular correlations between the electron, neutrino and recoil momenta following the [beta] decay of (un)polarized nuclei can be used to search for exotic currents contributing to the dominant V – A structure of the weak interaction. Precision measurements of the correlation parameters to 0.1% would be sensitive to (or meaningfully constrain) new physics, complementing other searches at large-scale facilities such as the LHC. Ion and atom traps provide an ideal source of very cold, short-lived radioactive nuclei in an extremely clean and open environment. As such, they are invaluable tools for precision measurements of [beta]-decay parameters which are sensitive to physics beyond the standard model. This talk will outline three such efforts. At TRIUMF in Vancouver, Canada, the TRINAT collaboration has demonstrated the ability to highly polarize (>99%) 37K atoms and measure the [beta] asymmetry parameter, A_β, to 0.3%. The TAMUTRAP facility at the Cyclotron Institute, Texas A&M University, will utilize a unique cylindrical Penning trap – by far the world’s largest ion trap with an inner diameter of 180 mm – to measure the [beta]-delayed proton decays of neutron-deficient nuclei. The 6He b collaboration is adapting the exquisitely precise cyclotron radiation emission spectroscopy (CRES) technique developed by Project 8 to search for evidence of tensor interactions in the energy spectrum from the [beta] decay of 6He. The status and goals of these projects will be described.

The 2020 Fall Meeting of the Division of Nuclear Physics of the American Physical Society will be held Oct. 29 - Nov. 1, 2020 https://indico.frib.msu.edu/e/DNP2020Fall

The National Synchrotron Light Source II (NSLS-II) is a 3 GeV , low emittance (H: 1 nm-rad and V: 8 pm-rad), high brightness third generation synchrotron light source at Brookhaven National Lab. It is to deliver a broad range of light to 60-70 beamlines at full built-out. The storage ring was commissioned in 2014 and began its routine operations in the December of the same year. Since then, we have been continuously installing and commissioning new insertion devices and beamlines. At this point the facility hosts 28 beamlines to deliver light from Infrared to hard x-ray. Over the past five years, the storage ring performance continuously improved, including 500 mA demonstration and 400 mA routine top off operation. In FY20, we delivered 5400 hrs beam time with 97% operation reliability. Towards the future, a program to explore upgrade paths for the NSLS-II was initiated in 2019, with the goal of dramatically increasing its brightness and flux, which requires significantly lower emittance. Instead of following the Multi-Bend Achromat (MBA) lattice approach, recently we proposed an alternative way to reach low emittance by use of a lattice element that we call 'Complex Bend'. The Complex Bend is a new concept of bending magnet consisting of a number of dipole poles with strong alternate focusing to maintain the beta-function and dispersion oscillating at very low values, thus reach low emittance. Candidate lattices have achieved ~30 pm-rad emittance with 5 mm on-momentum dynamic aperture to allow off-axis injection.

The advent of high precision measurements of neutrinos and their oscillations calls for accurate predictions of their interactions with nuclear targets utilized in the detectors. Achieving a comprehensive description of the different reaction mechanisms active in the broad range of energy relevant for oscillation experiments is a formidable challenge for both particle and nuclear Physics. I will present an overview of recent developments in the description of electroweak interactions within nuclear many-body approaches and discuss the future perspectives to support the experimental effort in this new precision era.

Committee: Remco Zegers (Chairperson), B. Alex Brown, Daniel Hayden, Artemis Spyrou, Nathan Whitehorn

Neutrinos are absurdly abundant, unfathomably light, and elusively shy: though trillions pass through your body every second, only a handful of them will interact over the course of a lifetime. The properties of these fundamental particles make their study difficult, but enlightening: neutrinos may even be able to explain how we came to exist in the first place. The phenomenon of neutrino oscillation, first observed in 2001, is the process by which a neutrino changes between three flavours (electron, muon, and tau) while travelling. Neutrino oscillation measurements hope to answer a number of fundamental questions, most importantly: Is there enough Charge-Parity violation in the lepton sector to explain the deficit of anti-matter in the observable universe? The Tokai-to-Kamioka (T2K) experiment, which has been taking data since 2010, measures neutrino flavour change between the east and west coasts of Japan. In the latest data we see an indication of significant differences in how neutrinos and anti-neutrinos oscillate---i.e. lepton-sector CP violation. This talk will introduce long-baseline neutrino oscillation measurements, present what we are learning from T2K data about fundamental symmetries, and what the near-future holds for this exciting field of research.

Committee: Jaideep Singh (Chairperson), Hendrik Schatz, Artemis Spyrou, Kirsten Tollefson, Vladimir Zelevinsky

Big bang nucleosynthesis provides a window to the physics of the universe just seconds after the big bang. Its predictions of the light element abundances of D, He-4, and Li-7 can be compared with observational determinations. Over the last several years, significant progress has been made in the determinations of deuterium and helium abundances and most importantly results from Planck measurements of the microwave background have provided precise values for the baryon density of the universe, a key input used in abundance predictions. Planck data is combined with BBN to test the consistency of the Standard Model. These predictions are also sensitive to the conditions when the temperature of the universe was ~ 1 MeV or ~ 10^10 K. Using inputs from the standard model of cosmology and particle physics yields excellent agreement between theory and experiment. Thus deviations from the standard model such as the number of particle degrees of freedom (often parametrized as the number of neutrino flavors) can be tested.

Committee: Greg Severin (Chairperson), Dave Morrissey, Sean Liddick, Greg Swain

Committee: Steven Lund (Chairperson), Tim Grotjohn, Felix Marti, Chong-Yu Ruan, John Verboncoeur

This presentation will overview the superconducting radio frequency devices required for the future Electron Ion Collider and ongoing work at Brookhaven National Laboratory addressing related technical challenges. One of the challenges of operating superconducting resonant cavities in hadron synchrotrons is the need to operate with large frequency sweeps, greater than 1% in some cases during beam acceleration. A physical example of these challenges is found in the refurbished 56 MHz superconducting accelerator system to be installed in the Relativistic Heavy Ion Collider in 2022. The 56 MHz superconducting system addresses synchrotron acceleration via a novel coupler and tuner which damp and detune the resonator during beam acceleration. A full review of the 56 MHz system upgrades and conclusions on how these results may impact plans for the Electron Ion Collider will be discussed.

Committee: Steven Lund (Chairperson), Selin Aviyente, Scott Bogner, Steven Lidia, Peter Ostroumov

Hosts: Alex Gade and Sanjay Reddy and Panelists: Andrew Cumming and Zach Meisel

Committee: Christopher Wrede (Chairperson), Saiprasad Ravishankar, Edward Brown, Kaitlin Cook, Darren Grant

We have recently measured the nuclear magnetic octupole moment of 45Sc. With a single valence proton outside of a magic calcium core, this isotope is ideally suited for an in-depth study of the many intriguing nuclear structure phenomena observed within the neighboring isotopes of calcium. We compare the nuclear magnetic octupole moment to shell-model calculations, and find that they cannot reproduce the experimental value of the nuclear magnetic octupole moment for scandium-45. We furthermore explore the use of Density Functional Theory for evaluating the nuclear magnetic octupole moment, and obtain values in line with the shell-model calculations. This work provides a crucial step in guiding future measurements of this fundamental quantity on radioactive scandium isotopes and will hopefully motivate a renewed experimental and theoretical interest.

Committee: William Lynch (Chairperson), Pawel Danielewicz, Morten Hjorth-Jensen, Kirsten Tollefson, Man-Yee Betty Tsang

Committee: Jaideep Singh (Chairperson), Oscar Naviliat-Cuncic, Wolfgang Mittig, Chong-Yu Ruan, Vladimir Zelevinsky

A complete description of the interplay between equilibration, dissipation, and fluctuation mechanisms in interacting quantum many-body systems is an open problem in physics at every scale [1]. In nuclear physics, equilibration of mass and neutron-to-proton asymmetries is studied in collisions of atomic nuclei in which nucleons can be transferred between initially isolated nuclei [2]. Nucleon transfer is also expected to be a source of dissipation by transforming kinetic energy into internal excitation [3]. However, since we are dealing with quantum systems there are quantal effects that influence the equilibration process. Among these are the shell effects and deformations. For low-energy collisions time-dependent Hartree-Fock (TDHF) [4] theory and its extensions provide a microscopic approach to study these effects and processes. In this presentation, we shall first discuss the collision dynamics to demonstrate some of these effects. After that we shall propose a universal measure to investigate the timescales of equilibration, dissipation, and fluctuation mechanisms [5]. Despite direct comparisons between wildly different systems spanning light and heavy nuclei at a range of collision energies, common timescales were found for each of the studied quantities. The longest process by far is mass equilibration, with a general equilibration time of 2x10-20s. Timescales for neutron-to-proton equilibration, mass fluctuation build up, kinetic energy dissipation, and angular momentum dissipation however are found to be on the order of 10-21s, an order of magnitude faster than that of mass equilibration. This vast separation implies the relative independence of dissipation mechanisms on mass equilibration, and that the primary generator of dissipative effects is fast nucleon exchange between interacting fragments. *This work has been supported by the U.S. DOE under grant No. DE SC0013847 with Vanderbilt University. [1] Eisert, M. Friesdorf, and C. Gogolin, Quantum many-body systems out of equilibrium, Nat. Phys. 11, 124 (2015). [2] A. Jedele, A. B. McIntosh, K. Hagel et al., Characterizing Neutron-Proton Equilibration in Nuclear Reactions with Subzeptosecond Resolution, Phys. Rev. Lett. 118, 062501 (2017). [3] Randrup, Mass transport in nuclear collisions, Nucl. Phys. A 307, 319?348 (1978). [4] C. Simenel and A. S. Umar, Heavy-ion collisions and fission dynamics with the time-dependent Hartree-Fock theory and its extensions, Prog. Part. Nucl. Phys. 103, 19?66 (2018). [5] C. Simenel, K. Godbey, and A. S. Umar, Phys. Rev. Lett. 124, 212504 (2020).

The Binding Block collaboration started in 2015 and since then has worked hard to develop material to explain nuclear physics to A-level students. In particular, we have created a simple activity based on the liquid-drop model which allows secondary school students to explore the uses of mathematical models and gain an intuitive understanding of the concept of binding energy, and in particular the significance of positive binding energy. Using simple computational tools (Excel files), students can perform simple manipulations on the different coefficients of the model to understand the role of each of its five terms. Students can use the spreadsheets to determine model parameters by optimising the agreement with real atomic mass data. This will subsequently be used to predict the limit of existence of the Segre chart and to find the minimum mass of a neutron star. In this talk, I'll present the material/activities we have created so far and I'll discuss my personal experience in the world of outreach.

One central paradigm in contemporary nuclear theory is to predict nuclear phenomena starting from nucleon interactions rooted in quantum chromodynamics. An array of many-body methods, combined with growing computational capabilities, have pushed such structure calculations to compute medium-mass nuclei. However, the calculations for scattering and reactions are much more limited, and their synergy with experimental measurements has rarely been discussed. A method that works for heavier nuclei and can efficiently incorporate outside information will be valuable for nuclear astrophysics and the coming FRIB program. In this talk, I will present my research program on developing such a method by using a computer-experiment strategy. I will highlight recent encouraging results on neutron-alpha and neutron--Oxygen-24 scattering. I will then discuss two essential components of the method: cluster-level theories and data analysis tools, their applications within and outside my ab initio method, and their ongoing developments in my research. They will demonstrate the organic synergy of the ab initio calculations and experimental measurements and point out future steps to generalize the ab initio method for reactions and three-cluster systems.

Nuclear short-range correlations (SRCs), i.e. the probability of finding few nucleons close to each other inside the nucleus, are an integral part of the description of nuclear systems, important also for neutrino studies, neutron-star structure and for the bound nucleon structure function. High-energy electron scattering is the main experimental technique to probe SRCs, while ab-initio calculations are mostly limited to nuclear distributions of light nuclei. To study the properties of SRCs and bridge the gap between experimental and ab-initio studies, we developed a new theory, called the generalized contact formalism. In this talk I will present the original contact formalism, designed for atomic systems, and our generalization for nuclear systems. Using this formalism, we have been able to obtain a comprehensive picture of two-body SRCs, identifying and quantifying their effects on various nuclear quantities, including momentum distributions, two-body densities, the spectral function, the Coulomb sum-rule, photo absorption rates and electron scattering cross sections. Describing all these quantities in a single framework allows confronting electron scattering SRC data with ab-initio nuclear structure calculations and different models of the nucleon-nucleon interaction. The contact formalism has also become an important tool used directly by leading experimental groups to simulate their experiments and analyze their data, leading to new insights based on more detailed and more accurate experimental data.

Supernovae and neutron star binary mergers are fascinating astrophysical sites, home to some of the most extreme phenomena observed in nature, and major sites for the production of heavy elements. Neutrinos, which lie at the center of the explosion mechanism, dictate the composition of nuclear matter responsible for nucleosynthesis, and provide a unique view into properties of dense matter, beyond standard model physics, and fundamental symmetries. In this talk, to underscore their key role in nuclear astrophysics, I will cover various intriguing aspects of their interactions with nuclear matter.

Precise knowledge of the interaction between the atomic nucleus and the surrounding electrons offers a complementary insight into the atomic nucleus and the fundamental particles and forces of nature. Exotic atoms and molecules - those containing nuclei with extreme proton-to-neutron ratios - can be tailored to investigate particular details of electron-nucleon interactions and enhanced their symmetry-violating properties. Thereby offering high sensitivity to access to unexplored nuclear phenomena, to study the violation of fundamental symmetries, and to search for new physics. In this talk, I will present recent results from laser spectroscopy experiments of these exotic species. The relevance of these results to some of the main questions of nuclear science will be discussed.

Nucleon removal (p, pN) reactions at intermediate energies have proven to be a strong tool to extract spectroscopic information from atomic nuclei. The development in recent years of high-density proton targets within radioactive beam facilities has allowed for the study of exotic asymmetric nuclei. Beyond their spectroscopic potency of (p, pN) reactions, they have received special interest as they may allow to clarify the current open question of the asymmetry dependence of the reduction factors (ratios between experimental and theoretical cross sections),which was found to be different for nucleon transfer [1] and nucleon knockout reactions with heavy targets (9Be and 12C) [2]. In this talk, I will present results for (p, pn) and (p, 2p) reactions using the Transfer to the Continuum formalism [3], focusing on the study of the reduction factors for different isotopes of oxygen and nitrogen recently measured by the R3B collaboration at GSI, Germany [4]. I will also present an extension of the Transfer to the Continuum formalism to study (p, pn) reactions applied to Borromean nuclei, in particular 11Li and 14Be. In order to further exploit the high-quality proton targets, (p, 3p) reactions appear as a promising probe to populate and study very neutron-rich nuclei, as the population of the second 2+ state in 78Ni from 80Zn(p, 3p) has shown [5]. Unfortunately, the mechanism through which (p, 3p) reactions take place is still unclear. As a first step to understand them, I will present a simple kinematical study of (p, 3p) reactions for recently measured cross sections and angular distributions for medium-mass nuclei. Finally, in a rather tangential topic I will present some results obtained in the application of non-locality to continuum-discretized coupled-channel (CDCC) calculations of (d, p) reactions, whose main result is the reduction of the dependence on the nucleon-nucleon interaction which was found for more approximate adiabatic calculations. [1] F. Flavigny et al, Phys. Rev. Lett. 110, 122503 (2013) [2] J. A. Tostevin and A. Gade, Phys. Rev. C 90, 057602 (2014) [3] A.M. Moro, Phys. Rev. C 92, 044605 (2015) [4] L. Atar et al, Phys. Rev. Lett. 120, 052501 (2018) [5] R. Taniuchi et al, Nature 569, 53 (2019)

The heaviest elements observed in nature are understood to be synthesized by the rapid neutron capture process (r process), but which astrophysical site(s) host the conditions capable of reaching these species remains an open question. Although the electromagnetic emission from the merger of binary neutron stars has been able to provide observational evidence for the synthesis of lanthanides, whether such events produce heavier elements such as gold, platinum, and the actinides remains uncertain. We will review recent work aiming to identify signatures of fission in the electromagnetic counterparts of events which, if observed, would reveal that neutron star mergers can synthesize not only the fissioning actinides but lighter elements such as platinum. The impact of nuclear physics uncertainties on our ability to interpret multi-messenger observables will be highlighted. The next generation of nuclear physics experiments play a key role in progressing our understanding of astrophysical outcomes, with experimental facilities such as FRIB producing hundreds of neutron-rich species for the first time. We will explore the opportunities for future experimental efforts to refine our knowledge of actinide and lanthanide production in the r process. For instance, an enhancement in lanthanide production seen in solar data, the r-process rare-earth abundance peak, could be intimately linked to nuclear structure features which may be able to be probed at upcoming experimental facilities. We will examine this possibility in the context of a statistical approach utilizing Markov Chain Monte Carlo which seeks to find conditions capable of producing a rare-earth peak consistent with both observational and experimental data. Since the nucleosynthetic outcome depends on the properties of the exotic nuclei populated in astrophysical events, studying the r-process signatures of actinide and lanthanide species permits theory, experiment, and observation to inform one another.

Committee: Luke Roberts (Chairperson), Scott Bogner, Sean Couch, William Lynch, Brain O'Shea

In modern accelerators, the ability to increase or maintain beam density and lifetime is essential. Historically, this has required the development and application of a variety of beam-cooling concepts and technologies to facilitate particle accumulation, higher luminosity and to counteract diffusive (heating) effects, such as intrabeam scattering (IBS), Touschek scattering and residual-gas scattering. One of the greatest conceptual and technological triumphs in this area was van der Meer’s Nobel-Prize-winning Stochastic Cooling (SC), which was vital in the accumulation of antiprotons and in the delivery of the beam quality required for the discovery of the W and Z bosons. Extension of the SC principle to optical frequencies and bandwidths ([delta]f~10^13 Hz) was first suggested in the early 1990s by Zolotorev, Zholents and Mikhailichenko and could increase achievable cooling rates by three to four orders of magnitude. In this talk, we will review the basic concepts of Optical Stochastic Cooling (OSC) and describe the experimental OSC program underway at Fermilab’s Integrable Optics Test Accelerator (IOTA) ring. We will also discuss development efforts focused on high-gain optical amplification for OSC and the use of OSC concepts and technology as a more general tool for phase-space control and measurement.

Due to the spread of COVID-19, the ISNET Local Organizing Committee will postpone the in-person conference for 2021. Virtual pre-conference December 14-18 2020, updates will follow. Thank you for your understanding. The Virtual pre-conference will be held from December 14 to 18 2020; in the format of 30-40 min. talk with 20-30 min. for discussions led by a panel and the speaker. A few ideas for lectures are: 1. Bayesian Basics 2. Model Emulation 3. Model Mixing 4. ML techniques for statistical analysis 5. Advanced Statistics Techniques for Analyzing Experimental Data 6. Resampling Techniques (e.g. bootstrap) Please contact us should you have any questions or ideas at isnet@frib.msu.edu

Nuclear scattering experiments are the window into the atomic nucleus. Particle distributions, many-body correlations, binding energies, and even properties of nuclear matter (NM) can be linked with scattering data in a consistent way using a nonlocal dispersive optical model (DOM). Both scattering and structure data are used to constrain the DOM self-energies of 12C, 40Ca, 48Ca, and 208Pb by enforcing a dispersion relation connecting the real and imaginary parts of these self-energies over all energy domains. Certain properties of finite nuclei, such as the neutron skin, can in turn help to determine the nuclear equation of state (EOS). I will present neutron skin predictions for 48Ca and 208Pb (the prediction of the 208Pb skin is in good agreement with the recent PREX-II result). To investigate how this connects to the EOS, I will present binding-energy densities calculated using the DOM self-energies. These densities reveal that the core of the nucleus (where the density is NM-lik e) minimally contributes to the total binding energy. With this in mind, the canonical method of extrapolating the saturation energy of NM from the empirical mass formula (E0 = -aV = -16 MeV) is suspect. In addition to NM properties, I will discuss how DOM self-energies can provide insight into the quenching of spectroscopic factors. Finally, I will conclude by discussing steps toward ab initio self-energies (optical potentials).

Studying interactions of photons and leptons with nuclei not only helps us find answers to some of the most important questions in atomic physics, astrophysics, cosmology and neutrino physics, but also serves as a probe of several interesting short- and long-range phenomena in nuclei. This feature can be best exploited by looking at nuclei through the different lenses---appropriate for the length scale of the problem at hand---provided by a hierarchy of nuclear effective field theories. I will discuss chiral and pionless effective-field-theory studies of electroweak reactions of the deuteron, calculations of electric dipole transition strength of halo nuclei in halo effective field theory as well as electromagnetic responses of Helium-4, Oxygen-16 and Calcium-40 in coupled-cluster theory. Connections to radioactive ion beam experiments will be emphasized.

Committee: Hendrik Schatz (Chairperson), James Linnemann, Wolfgang Mittig, Fernando Montes, Carl Schmidt

Committee: Sean Liddick (Chairperson), Paul Mantica, Dave Morrissey, Artemis Spyrou

Committee: Alexandra Gade (Physics PhD Chairperson), Matthew Hill (Dual PhD CMSE Chairperson), Morten Hjorth-Jensen, Claudio Kopper, Artemis Spyrou

Committee: Artemis Spyrou (Chairperson), Sean Liddick, Christopher Wrede, Vladimir Zelevinsky, Stephen Zepf