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

Abstract

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 L\'evy type source distributions. The L\'evy source parameters are extracted as functions of transverse mass and collision centrality. These source parameters include the correlation strength $\lambda$, the L\'evy stability index $\alpha$, and the L\'evy 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.