Mon·Sep 19, 2022Monday·September 19, 2022

1. 01*

   Results on system size dependence of strangeness production in the CERN SPS energy range from NA61/SHINE

   Piotr Podlaski🇵🇱

   NA61/SHINE is a multipurpose fixed-target facility at the CERN Super Proton Synchrotron. The main goals of the NA61/SHINE strong interactions program are to discover the critical point of strongly interacting matter and study the properties of the onset of deconfinement. To reach these goals, hadron production measurements are performed in the form of a two-dimensional scan by varying collision energy and system size. The Collaboration has recently finished data acquisition for its original program on strong interactions, accumulating broad data samples on hadron production in various systems in the SPS energy range.\\ In this contribution, the NA61/SHINE results on identified charged kaon and pion production in p+p, Be+Be and Ar+Sc collisions at the SPS energy range ($\sqrt{s_{NN}}$=5.1--17.3 GeV) are presented. The NA61/SHINE measurements of small and intermediate-mass ion collisions establish an interesting system size dependence, showing a rapid change of hadron production properties that starts when moving from Be+Be to Ar+Sc system. In particular, Ar+Sc is the smallest system for which a significant enhancement of $K^{+}/{\pi }^{+}$ ratio with respect to $p$+$p$ collisions is observed. Obtained energy and system size dependence of the measured charged hadron multiplicities are compared with available world data and various theoretical models.

   nucl-exEPJ Web Conf.(2023)·2 citations
2. 02*

   Beam Energy Dependence of Triton Production and Yield Ratio (${\mathrm{N}}_t\times {\mathrm{N}}_p/{\mathrm{N}}_d^2$) in Au+Au Collisions at RHIC

   STAR Collaboration: M. I. Abdulhamid🇪🇬 · B. E. Aboona🇺🇸 · J. Adam🇨🇿 · J. R. Adams🇺🇸 · G. Agakishiev🇷🇺 · I. Aggarwal🇮🇳 · M. M. Aggarwal🇮🇳 · Z. Ahammed🇮🇳 · A. Aitbaev🇷🇺 · I. Alekseev🇷🇺 · D. M. Anderson🇺🇸 · A. Aparin🇷🇺 and 345 other authors

   We report the triton ($t$) production in mid-rapidity ($|y|<$ 0.5) Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$= 7.7--200 GeV measured by the STAR experiment from the first phase of the beam energy scan at the Relativistic Heavy Ion Collider (RHIC). The nuclear compound yield ratio (${\mathrm{N}}_t\times {\mathrm{N}}_p/{\mathrm{N}}_d^2$), which is predicted to be sensitive to the fluctuation of local neutron density, is observed to decrease monotonically with increasing charged-particle multiplicity ($d{N}_{ch}/d\eta$) and follows a scaling behavior. The $d{N}_{ch}/d\eta$ dependence of the yield ratio is compared to calculations from coalescence and thermal models. Enhancements in the yield ratios relative to the coalescence baseline are observed in the 0\%-10\% most central collisions at 19.6 and 27 GeV, with a significance of 2.3$\sigma$ and 3.4$\sigma$, respectively, giving a combined significance of 4.1$\sigma$. The enhancements are not observed in peripheral collisions or model calculations without critical fluctuation, and decreases with a smaller $p_T$ acceptance. The physics implications of these results on the QCD phase structure and the production mechanism of light nuclei in heavy-ion collisions are discussed.

   nucl-exhep-exhep-phhep-th+1PRL(2023)·92 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.