Thu·Jan 27, 2022Thursday·January 27, 2022

1. 01*

   Nucleon-Nucleon Short-Ranged Correlations, $\beta$ Decay and the Unitarity of the CKM Matrix

   Levi Condren🇺🇸 · Gerald A. Miller🇺🇸

   The influence of nucleon-nucleon short-ranged correlations (SRC) on nuclear super-allowed $\beta$ decay is examined. The need for this is driven by the observed depletion of spectroscopic strength obtained in studies of $(e,e^{\prime })$ and $(d{,}^3\mathrm{He})$ reactions on a wide variety of nuclei. We show that the influence of SRC is model-dependent, but may be very substantial. The ${}^{46}$V nucleus is used as an example. The resulting impact on studies of the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element is discussed.

   ↳ nucl-thhep-phnucl-exPRC(2022)·14 citations
2. 02*

   PANDA Barrel DIRC: From Design to Component Production

   G Schepers🇩🇪 · A Belias🇩🇪 · R Dzhygadlo🇩🇪 · A Gerhardt🇩🇪 · D Lehmann🇩🇪 · K Peters🇩🇪 · C Schwarz🇩🇪 · J Schwiening🇩🇪 · M Traxler🇩🇪 · L Schmitt🇩🇪 · M Böhm🇩🇪 · S Krauss🇩🇪 and 16 other authors

   Excellent particle identification (PID) will be essential for the PANDA experiment at FAIR. The Barrel DIRC will separate kaons and pions with at least 3 s.d. for momenta up to 3.5 GeV/c and polar angles between 22 and 140 deg. After successful validation of the final design in the CERN PS/T9 beam line, the tendering process for the two most time- and cost-intensive items, radiator bars and MCP-PMTs, started in 2018. In Sep. 2019 Nikon was selected to build the fused silica bars and successfully completed the series production of 112 bars in Feb. 2021. Measurements of the mechanical quality of the bars were performed by Nikon and the optical quality was evaluated at GSI. In Dec. 2020, the contract for the fabrication of the MCP-PMTs was awarded to PHOTONIS and the delivery of the first-of-series MCP-PMTs is expected in July 2021. We present the design of the PANDA Barrel DIRC as well as the status of the component series production and the result of the quality assurance measurements.

   ↳ physics.ins-detnucl-exJ.Phys.Conf.Ser.(2022)·1 citation
3. 03*

   Impact of nuclear structure on the CME background in ${}_{44}^{96}$Ru + ${}_{44}^{96}$Ru and ${}_{40}^{96}$Zr + ${}_{40}^{96}$Zr collisions at $\sqrt{s_{NN}}$ = 7.7 $\sim$ 200 GeV from a multiphase transport model

   Fei Li🇨🇳 · Yu-Gang Ma🇨🇳 · Song Zhang🇨🇳 · Guo-Liang Ma🇨🇳 · Qi-Ye Shou🇨🇳

   Impacts of nuclear structure on multiplicity ($N_{ch}$) and anisotropic flows ($v_2$ and $v_3$) in the isobaric collisions of ${}_{44}^{96}$Ru + ${}_{44}^{96}$Ru and ${}_{40}^{96}$Zr + ${}_{40}^{96}$Zr at $\sqrt{s_{NN}}$ = 7.7, 27, 62.4 and 200 GeV are investigated by using the string melting version of A MultiPhase Transport (AMPT) model. In comparison with the experimental data released recently by the STAR collaboration, it is found that the impact of quadrupole deformation ${\beta }_2$ on the $v_2$ difference is mainly manifested in the most central collisions, while the octupole deformation ${\beta }_3$ is in the near-central collisions, and the neutron skin effect dominates in the mid-central collisions. Viewing from the energy dependence, these effects are magnified at lower energies.

   ↳ nucl-thhep-phnucl-exPRC(2022)·17 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.