Thu·Jun 29, 2023Thursday·June 29, 2023

1. 01*

   Intruder configurations in ${}^{29}$Ne at the transition into the island of inversion: Detailed structure study of ${}^{28}$Ne

   H.Wang · M.Yasuda · Y.Kondo · T.Nakamura · J.A. Tostevin · K.Ogata · T.Otsuka · A.Poves · N.Shimizu · K.Yoshida · N.L.Achouri · H.Al Falou and 84 other authors

   Detailed $\gamma$-ray spectroscopy of the exotic neon isotope ${}^{28}$Ne has been performed for the first time using the one-neutron removal reaction from ${}^{29}$Ne on a liquid hydrogen target at 240~MeV/nucleon. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for ${}^{28}$Ne and the negative-parity states are identified for the first time. The measured partial cross sections and momentum distributions reveal a significant intruder $p$-wave strength providing evidence of the breakdown of the $N=20$ and $N=28$ shell gaps. Only a weak, possible $f$-wave strength was observed to bound final states. Large-scale shell-model calculations with different effective interactions do not reproduce the large $p$-wave and small $f$-wave strength observed experimentally, indicating an ongoing challenge for a complete theoretical description of the transition into the island of inversion along the Ne isotopic chain.

   nucl-exnucl-thPLB(2023)·6 citations
2. 02*

   Centrality-dependent Lévy HBT analysis in $\sqrt{s_{{}_{\text{NN}}}}=5.02$ TeV PbPb collisions at CMS

   Balázs Kórodi (for the CMS Collaboration)🇭🇺

   The measurement of two-particle Bose-Einstein momentum correlation functions are presented using $\sqrt{s_{{}_{\text{NN}}}}=5.02$ TeV PbPb collision data, recorded by the CMS experiment in 2018. The measured correlation functions are discussed in terms of Lévy type source distributions. The Lévy source parameters are extracted as functions of transverse mass and collision centrality. These source parameters include the correlation strength $\lambda$, the Lévy stability index $\alpha$, and the Lévy scale parameter $R$. The source shape, characterized by $\alpha$, is found to be neither Gaussian nor Cauchy. A hydrodynamic-like scaling of $R$ is also observed.

   nucl-exhep-exUniverse(2023)·3 citations
3. 03*

   A method for probing the formation of quark matter

   Gao-Chan Yong🇨🇳

   Based on a multi-phase transport model for relativistic heavy-ion collisions, effects of the parton scatterings on the production of strangeness in relativistic heavy-ion collisions are studied. It is found that the distributions of strange quark and strange baryon, especially for the double strangeness ${\Xi }^{-}$, are significantly affected by the parton scatterings in heavy-ion collisions below $\sqrt{s_{NN}}\sim$ 10 GeV. Given parton scatterings as a signal of the formation of quark matter, the transverse momentum distribution of the ratio of single and double strangeness $(\Lambda +{\Sigma }^0)/{\Xi }^{-}$ produced in heavy-ion collisions may serve as a potential probe of the emergence of quark matter, or equivalently, the occurrence of hadron-quark phase transition in relativistic heavy-ion collisions.

   ↳ nucl-thnucl-exPLB(2023)·6 citations
4. 04*

   Phase diagram determination at fivefold nuclear compression

   Gao-Chan Yong🇨🇳

   In the standard model of particle physics, the strong force is characterized by the theory of quantum chromodynamics (QCD). It is commonly understood from QCD properties that hadrons, at sufficiently high temperatures or densities, melt into their constituent quarks, thereby undergoing a deconfinement transition to a new phase of quarks and gluons, often referred to as quark matter or quark-gluon plasma (QGP) \cite{qcd00,qcd01}. Although QGP has been observed in relativistic heavy-ion collisions \cite{qgp1,qgp2}, uncertainties remain about when the onset of deconfinement occurs. After comparing simulations from a reliable hadron and quark relativistic transport model with recent data from the STAR experiment, we determined that the onset of the hadron-quark phase transition occurs at about five times nuclear compression, corresponding to temperature $T\sim$ 112 MeV and baryon chemical potential ${\mu }_B\sim$ 586 MeV, in the nuclear matter phase diagram. This discovery has significant implications for the studies of both the early and present universe \cite{ann2006}, including the fraction of dark matter formed in the early universe \cite{bhd2016,bhf1997,pbh20} and the structure and dynamics of neutron stars and their mergers \cite{nature2020}.

   ↳ nucl-thnucl-exPLB(2024)·10 citations
5. 05*

   Corrections to the Forward Limit Dispersion Relations for $\gamma Z$-Exchange Contributions

   Qian-Qian Guo🇨🇳 · Hai-Qing Zhou🇨🇳

   The weak charge of the proton $Q_{\text{w}}$ is one of the most fundamental quantities in physics. It can be determined by measuring the parity asymmetry $A_{\text{PV}}$ in elastic $ep$ scattering, where the $\gamma Z$-exchange contributions are crucial. For the past fifteen years, dispersion relations (DRs) in the forward limit have been widely used as a model-independent method to estimate these contributions. In this work, we study corrections to these forward-limit DRs. We first estimate these corrections using pointlike interactions as an illustrative example. We then estimate the $\gamma Z$-exchange contributions for the upcoming P2 experiment through both direct calculation and the forward-limit DRs, within the framework of low-energy effective interactions. The results indicate that the correction to the forward-limit DR for ${\square }_{\gamma Z}^V$ is around 47\% for the upcoming P2 experiment, which will significantly modify the extracted value of $Q_{\text{w}}$.

   ↳ hep-phnucl-exnucl-thPRC(2024)·3 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.