Mon·Jun 19, 2023Monday·June 19, 2023

1. 01*

   Skin values and matter radii of ${}^{208}$Pb and ${}^{58,60,64}$Ni based on reaction cross section of ${}^{3,4}$He scattering (published in Results in Physics)

   Shingo Tagami🇯🇵 · Tomotsugu Wakasa🇯🇵 · Masanobu Yahiro🇯🇵

   The PREX group reported a new skin value, $r_{\mathrm{skin}}^{208}(PREX2)=0.283\pm 0.071\mathrm{fm}$. Using the chiral (Kyushu) $g$-matrix folding model with the proton and neutron densities determined with D1S+GHFB+AMP, we determined neutron skin thickness $r_{\mathrm{skin}}^{208}(\exp )$ from reaction cross sections ${\sigma }_{\mathrm{R}}(\exp )$ of p+${}^{208}$Pb scattering. The method also yielded $r_{\mathrm{skin}}^{208}(\exp )$ from ${\sigma }_{\mathrm{R}}(\exp )$ of ${}^4$He+${}^{208}$Pb scattering. We accumulated the 206 EoSs and determined a sloop parameter from the 206 EoSs. The value yields $r_{\mathrm{skin}}^{208}=0.102\sim 0.354\mathrm{fm}$. As the first aim, we first determine $r_{\mathrm{skin}}^{208}(\exp )$ from ${\sigma }_{\mathrm{R}}(\exp )$ of ${}^3$He scattering on ${}^{208}$Pb target and take the weighted mean and its error for $r_{\mathrm{skin}}^{208}(PREX2)$, three skin values of p+${}^{208}$Pb, ${}^{3,4}$He+${}^{208}$Pb scattering and the $r_{\mathrm{skin}}^{208}$ based on the 206 EoSs. As the second aim, we determine matter radii $r_m(\exp )$ of ${}^{58,60,64}$Ni from ${\sigma }_{\mathrm{R}}(\exp )$ of ${}^{3,4}$He scattering on ${}^{58,60,64}$Ni targets. Our result is $r_{\mathrm{skin}}^{208}(\exp )=0.512\pm 0.268\mathrm{fm}$ for ${}^3$He+${}^{208}$Pb scattering. Our conclusion is $r_{\mathrm{skin}}^{208}=0.285\pm 0.030\mathrm{fm}$. It is determined from the 5 skin values mentioned above.

   nucl-exnucl-th1 citation
2. 02*

   Kaon femtoscopy with Lévy-stable sources from $\sqrt{s_{{}_{\mathrm{NN}}}}=200$ GeV $\mathrm{Au}+\mathrm{Au}$ collisions at RHIC

   Ayon Mukherjee🇭🇺

   Femtoscopy has the capacity to probe the space-time geometry of the particle-emitting source in heavy-ion collisions. In particular, femtoscopy of like-sign kaon-pairs may shed light on the origin of non-Gaussianity of the spatial emission probability density. The momentum-correlations between like-sign kaon-pairs are, hence, measured in data recorded by the STAR experiment, from $\sqrt{s_{{}_{\mathrm{NN}}}}=200$ GeV $\mathrm{Au}+\mathrm{Au}$ collisions at RHIC, BNL. Preliminary results hint at the, possible, existence of non-Gaussian, Lévy-stable sources; and signal the, likely, presence of an anomalous diffusion process; for the identically-charged kaon-pairs so produced. More statistically significant studies, at lower centre-of-mass energies, may contribute to the search for the critical end point of QCD as well.

   nucl-exhep-exUniverse(2023)·8 citations
3. 03*

   Early-times Yang-Mills dynamics and the characterization of strongly interacting matter with statistical learning

   Matthew R. Heffernan🇨🇦 · Charles Gale🇨🇦 · Sangyong Jeon🇨🇦 · Jean-François Paquet🇺🇸

   In ultrarelativistic heavy-ion collisions, a plasma of deconfined quarks and gluons is formed within $1$ fm/c of the nuclei's impact. The complex dynamics of the collision before $\approx 1$ fm/c is often described with parametric models, which affect the predictivity of calculations. In this work, we perform a systematic analysis of LHC measurements from Pb-Pb collisions, by combining an \emph{ab-initio} model of the early stage of the collisions with a hydrodynamic model of the plasma. We obtain state-of-the-art constraints on the shear and bulk viscosity of quark-gluon plasma. We mitigate the additional cost of the ab-initio initial conditions by combining Bayesian model averaging with transfer learning, allowing us to account for important theoretical uncertainties in the hydrodynamics-to-hadron transition. We show that, despite the apparent strong constraints on the shear viscosity, metrics that balance the model's predictivity with its degree of agreement with data do not prefer a temperature-dependent specific shear viscosity over a constant value. We validate the model by comparing with discriminating observables not used in the calibration, finding excellent agreement.

   ↳ nucl-thhep-phnucl-exPRL(2024)·41 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.