Thu·Mar 10, 2022Thursday·March 10, 2022

1. 01*

   Signatures of shape phase transitions in krypton isotopes based on relativistic energy density functionals

   K.E. Karakatsanis🇬🇷 · K. Nomura🇭🇷

   Spectroscopic properties that characterize the shape phase transitions in krypton isotopes with the mass $A\approx 80$ region are investigated within the framework of the nuclear density functional theory. Triaxial quadrupole constrained self-consistent mean-field calculations that employ relativistic energy density functionals and a pairing interaction are carried out for the even-even nuclei ${}^{76-86}$Kr. The spectroscopic properties are computed by solving the triaxial quadrupole collective Hamiltonian, with the ingredients, i.e., the deformation-dependent moments of inertia and mass parameters, and the collective potential, determined by using the SCMF solutions as microscopic inputs. Systematic behaviors of the SCMF potential energy surfaces, the corresponding low-energy spectra, electric quadrupole and monopole transition probabilities, and the fluctuations in the triaxial quadrupole deformations indicate evolution of the underlying nuclear structure as functions of the neutron number, that is characterized by a considerable degree of shape mixing. A special attention is paid to the transitional nucleus ${}^{82}$Kr, which has been recently identified experimentally as an empirical realization of the E(5) critical-point symmetry.

   ↳ nucl-thnucl-exPRC(2022)·7 citations
2. 02*

   Longitudinal dynamics and particle production in relativistic nuclear collisions

   Chun Shen🇺🇸 · Björn Schenke🇺🇸

   This work presents a three-dimensional dynamical initialization model for relativistic heavy-ion collisions, implementing local energy-momentum conservation and baryon charge fluctuations at string junctions. Constraining parameters using experimental data from p+p collisions at various collision energies, the model provides a very good description of the charged hadron and net proton rapidity distributions in Au+Au collisions from 7.7 to 200 GeV and Pb+Pb collisions at 8.77 and 17.3 GeV. We demonstrate the importance of fluctuations of baryon densities to string junctions for describing net-proton distributions at collision energies of 62.4 and 200 GeV. Including this improved baryon stopping description along with the requirement of strangeness neutrality also yields a good description of identified particle yields as functions of the collision energy above 7.7 GeV. We further study asymmetric p+Al and (p, d, ${}^3$He)+Au collisions at the top RHIC energy and p+Pb, Xe+Xe, and Pb+Pb collisions at LHC energies. We identify the produced particle rapidity distributions in asymmetric collision systems as particularly useful for constraining models of the early-time longitudinal dynamics.

   ↳ nucl-thhep-phnucl-exPRC(2022)·80 citations
3. 03*

   Special Issue on Advances in Chiral Quark Models

   Jorge Segovia🇪🇸

   The number of exotic candidates in both light- and heavy-quark hadron sectors has increased dramatically since the discovery by the Belle Collaboration of the so-called $X(3872)$ in 2003. It is clear that the simple quark model picture needs an extension and thus the last twenty years have witnessed an explosion of related theoretical and experimental activity. The ultimate goal of theory is to describe the properties of exotic states from the first principles of Quantum Chromodynamics (QCD), which is the non-Abelian Quantum Field Theory that describes the strong interaction. However, since this task is quite challenging, a more modest goal to start with is the development of QCD-motivated phenomenological models that specify the colored constituents, how they are clustered, and the forces between them. This Special Issue invited contributions reporting recent advances of phenomenological quark models in the study of hadron's spectrocopy, structure, and interactions, paying special attention to the exotic candidates but without losing sight of the conventional states. In response to the call for papers, and after a comprehensive peer review process, 8 articles qualified for acceptance in the final edition of the Special Issue. The authors are from geographically distributed countries such as Spain, South Africa, Ghana, China, Brazil, Argentina. This reflects the impact of the proposed topic and the effective organization of the guest editorial team of this Special Issue.

   ↳ hep-phhep-exhep-latnucl-ex+1Symmetry(2021)·0 citations
4. 04*

   A backing detector for order-keV neutrons

   A. Biekert🇺🇸 · L. Chaplinsky🇺🇸 · C.W. Fink🇺🇸 · M. Garcia-Sciveres🇺🇸 · W. C. Gillis🇺🇸 · W. Guo🇨🇳 · S.A. Hertel🇺🇸 · G. Heuermann🇺🇸 · X. Li🇨🇳 · J. Lin🇺🇸 · R. Mahapatra🇺🇸 · D.N. McKinsey🇺🇸 and 14 other authors

   We have designed and tested a large-area (0.15~m${}^2$) neutron detector based on neutron capture on \ce{^{6}Li}. The neutron detector design has been optimized for the purpose of tagging the scattering angle of keV-scale neutrons. These neutron detectors would be employed to calibrate the low-energy ($<$100 eV) nuclear recoil in detectors for dark matter and coherent elastic neutrino nucleus scattering (CE$\nu$NS). We describe the design, construction, and characterization of a prototype. The prototype is designed to have a tagging efficiency of $\sim$25\% at the relevant $\mathcal{O}$(keV) neutron energies, and with a mean capture time of $\sim$17$\mu$s. The prototype was characterized using a \ce{^{252}Cf} neutron source and agreement with the simulation was observed within a few percent level.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2022)·6 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.