High-energy electron cooling is being considered for several accelerator physics projects worldwide, including for the Electron Ion Collider under design at BNL. Since accelerating dc electron beams above few MeV is technologically challenging, rf-acceleration of electron bunches becomes a practical approach for high-energy applications. A world's first electron cooling of ion beams employing such rf-accelerated electron bunches was recently demonstrated at BNL using the Low Energy RHIC electron Cooler (LEReC) [1]. Many challenges associated with such an approach were successfully overcome. The cooling task becomes even more challenging when one attempts to cool ion beams in collisions, requiring careful optimization between the electron cooling process and the ion beam lifetime due to various effects, including the beam-beam interactions. In this presentation, we discuss first successful application of electron cooling technique for colliding ion beams in RHIC. [1] A.V. Fedotov et al., 'Experimental demonstration of hadron beam cooling using radio-frequency accelerated electron bunches', Phys. Rev. Letters 124, 084801 (2020) Work supported by the U.S. Department of Energy.

We calculate the structure of the hypertriton in pionless effective field theory and find a pronounced Lambda-deuteron cluster structure. This motivates our investigation of the hypertriton lifetime as a function of the Lambda separation energy in an effective field theory with Lambda and deuteron degrees of freedom. We also consider the impact of new measurements of the weak decay parameter of the Lambda. While the sensitivity of the total width to B_Lambda is small, the partial widths for decays into individual final states and the experimentally measured ratio R=Gamma_3He/(Gamma_3He+Gamma_pd) show a strong dependence. We comment on recent measurements of hypertriton properties in heavy ion collisions.

Nowadays, computationally efficient many-body methods can be used to perform first-principles calculations for atomic nuclei up to mass A~150. This progress has made it possible to confront modern two- and three-nucleon interactions from Chiral Effective Field Theory with a wealth of experimental data, and provide important guidance in their ongoing refinement. In my talk, I will focus on one such many-body approach, the In-Medium Similarity Renormalization Group (IMSRG). The IMSRG not only offers a means to directly compute certain nuclear properties, but also provides a powerful framework for designing "hybrid" methods that allow us to tackle nuclei with strong collective correlations, e.g., due to intrinsic deformation. I will present IMSRG applications to the first-principles description of (doubly) open-shell nuclei, including candidate nuclei for fundamental symmetry tests. I will also give an overview of new developments that promise to once again increase the capabilities of the IMSRG and related nuclear structure methods in the coming years.

This webinar will highlight the critical role of partnerships in support of nuclear physics research. Representatives from the Department of Energy's Office of Science for Nuclear Physics, Jefferson Lab, and Brookhaven National Laboratory will describe the range of world-class expertise, facilities, and resources available throughout the DOE National Laboratory Network, as well how advances in nuclear physics impact science and society. Looking to the future, we will also discuss the rich scientific program planned for the newly approved Electron Ion Collider (EIC), as well as hear from academic researchers advancing science through partnerships with Argonne National Laboratory, Facility for Rare Isotope Beams, Jefferson Lab, and Lawrence Berkeley National Laboratory.