${\text{K}}_{\text{S}}^0-{\text{K}}_{\text{S}}^0$ femtoscopy in Pb$-$Pb collisions at $\sqrt{{\text{s}}_{\mathrm{NN}}}=5.02$ TeV at the LHC

Abstract

Results from a one-dimensional femtoscopic analysis of ${\mathrm{K}}_{\mathrm{S}}^0-{\mathrm{K}}_{\mathrm{S}}^0$ correlations in Pb$-$Pb collisions at the center-of-mass energy $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV using data collected by the ALICE experiment at the LHC are presented. The source radius $R$ and correlation strength $\lambda$ are studied as a function of centrality and pair-transverse momentum ($k_{\mathrm{T}}$) to provide insight into the space-time structure and composition of the particle-emitting source. The observed trends of radii as a function of $k_{\mathrm{T}}$ and centrality are consistent with the collective expansion of the system. Comparisons with measurements at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV by the ALICE Collaboration show agreement across multiplicities and $k_{\mathrm{T}}$. Hydrokinetic model predictions match the most central collision results but deviate in peripheral events, potentially reflecting limitations in the model's description of peripheral collisions. A comparison with recent measurements at the same energy by the CMS Collaboration shows compatibility in both $R$ and $\lambda$ within 1.3$\sigma$. These results extend previous ${\mathrm{K}}_{\mathrm{S}}^0-{\mathrm{K}}_{\mathrm{S}}^0$ femtoscopy to a higher energy, providing a consistent baseline for future comparisons.

Comments: 25 pages, 8 captioned figures, 3 tables, authors from page 20, submitted to PLB, figures at http://alice-publications.web.cern.ch/node/13245