Mon·Apr 28, 2025Monday·April 28, 2025

1. 01*

   Probing Quantum Phenomena through Photoproduction in Relativistic Heavy-Ion Collisions

   James Daniel Brandenburg🇺🇸 · Spencer R. Klein🇺🇸 · Zhangbu Xu🇺🇸 · Shuai Yang🇨🇳 · Wangmei Zha🇨🇳 · Jian Zhou🇨🇳

   Photoproduction in ultra-peripheral relativistic heavy-ion collisions displays many unique features, often involving quantum mechanical coherence and two-source interference between photon emission from the two ions. We review the recent experimental results from RHIC and the LHC and theoretical studies of coherent vector meson photoproduction, emphasizing the quantum mechanical aspects of the interactions and the entanglement between the final state particles. These studies enrich our understanding of non-local realism, underscore the critical role of the polarization of the photon source, quantum interference and nuclear effect on the gluon distribution. It paves a way for quantitatively probing the quantum nature of these high-energy nuclear collisions.

   nucl-exnucl-thquant-phPPNP(2025)·9 citations
2. 02*

   Horizontal 1 K refrigerator with novel loading mechanism for polarized solid targets

   J. Brock🇺🇸 · C. Carlin🇺🇸 · D. Griffith🇺🇸 · M. Hoegerl · P. Hood · C. Flanagan · T. Kageya🇺🇸 · C.D. Keith🇺🇸 · V. Lagerquist🇺🇸 · J.D. Maxwell🇺🇸 · D.M. Meekins · P. Pandey🇺🇸 · S. Witherspoon

   We describe a helium evaporation refrigerator used to cool dynamically polarized proton and deuteron targets for electron-scattering experiments using the CEBAF Large Acceptance Spectrometer CLAS12 at Jefferson Lab. The geometry of the CLAS12 detector systems places severe design and construction constraints on the refrigerator and its ancillary equipment, resulting in a horizontal cryostat with a length of 4 m. The 16 cm${}^3$ target samples, consisting of frozen ammonia (NH3 or ND3), are loaded at the upstream end of the cryostat and moved to the beam-interaction region using a novel transport mechanism. At this location they are cooled with superfluid helium and polarized via dynamic nuclear polarization at 1 K and 5 T. In this manner samples can be replaced and cooled to 1 K in about 30 minutes without disturbing any elements of the electron beam line or particle detection system. We estimate that this method saved 18 days of valuable beam time over the course of a recent, 88-day long experiment.

   ↳ physics.ins-detnucl-exCryogenics(2025)·0 citations
3. 03*

   Equation of state and Fermi liquid properties of dense matter based on chiral effective field theory interactions

   Faruk Alp🇩🇪 · Yannick Dietz🇩🇪 · Kai Hebeler🇩🇪 · Achim Schwenk🇩🇪

   We present results for the equation of state of symmetric nuclear matter and pure neutron matter obtained in many-body-perturbation theory (MBPT) up to third order, based on various chiral two- and three-nucleon interactions used in ab initio calculations of nuclei. We extract equation of state properties, such as the incompressibility and the symmetry energy, and discuss estimates of the theoretical uncertainties due to neglected higher-order contributions in the MBPT expansion as well as the chiral effective field theory expansion. In addition, we discuss the Fermi liquid approach to nuclear matter. We calculate all two- and three-nucleon contributions to the quasiparticle interaction up to second order in MBPT and present results for the Landau parameters, effective mass, and speed of sound for pure neutron matter.

   ↳ nucl-thastro-ph.HEnucl-exPRC(2025)·24 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.