Kaon femtoscopy in Pb-Pb collisions at sNN=2.76 TeV

Abstract

We present the results of three-dimensional femtoscopic analyses for charged and neutral kaons recorded by ALICE in Pb-Pb collisions at √ s NN = 2.76 TeV. Femtoscopy is used to measure the space-time characteristics of particle production from the effects of quantum statistics and final-state interactions in two-particle correlations. Kaon femtoscopy is an important supplement to that of pions because it allows one to distinguish between different model scenarios working equally well for pions. In particular, we compare the measured three-dimensional kaon radii with a purely hydrodynamical calculation and a model where the hydrodynamic phase is followed by a hadronic rescattering stage. The former predicts an approximate transverse mass (m T ) scaling of source radii obtained from pion and kaon correlations. This m T scaling appears to be broken in our data, which indicates the importance of the hadronic rescattering phase at LHC energies. A k T scaling of pion and kaon source radii is observed instead. The time of maximal emission of the system is estimated by using the three-dimensional femtoscopic analysis for kaons. The measured emission time is larger than that of pions. Our observation is well supported by the hydrokinetic model predictions.

Bulk observables in Pb+Pb collisions at sNN=5.02TeV at the CERN Large Hadron Collider within the integr

“…Comparing kaon and pion points, one can see the approximate k T scaling between two dependencies at k T > 0.4 GeV/c, repeating the behavior observed for the collisions at √ s NN = 2.76 TeV and noticed in iHKM simulations [19] prior to the experimental confirmation in Ref. [20]. In Figs.…”

One-dimensional charged kaon femtoscopy in p -Pb collisions at sNN = 5.02 TeV

“…The EPOS 3 calculations for the radii without the cascade exhibit practically no k T dependence and do not describe the data, while the data are well reproduced by the full EPOS 3 model calculations thereby showing the importance of the hadronic cascade phase at LHC energies. This observation agrees with the conclusion from the threedimensional K ± femtoscopic analysis in Pb-Pb collisions at √ s NN = 2.76 TeV [47] where the hydrokinetic model HKM [56] with the hadronic rescattering phase described the charged kaon femtoscopic radii well. The extracted experimental λ values are about 0.45, whereas the EPOS 3 ones are about 0.65, i.e., apparently larger than the experimental λ values.…”

“…The obtained correlation function C raw was also corrected for purity before the fit [14,47] according to…”

Strangeness S = −2 baryon-baryon interactions and femtoscopic correlation functions in covariant chiral effective field theory*

“…In the last few years, there has been remarkable progress in studies of baryon-baryon interactions, both experimentally and theoretically. In particular, it was demonstrated that the momentum correlations between a pair of hadrons produced in heavy-ion collisions depend on quantum statistical effects and the space-time structure of the emitting source [29][30][31][32][33][34][35][36][37], in addition to being sensitive to the final-state interactions of the emitted hadron pair [38][39][40][41][42]. Because of the abundant hyperons produced in relativistic heavy-ion collisions and the excel-lent capabilities of detectors to identify particles and measure their momenta, the measurements of momentum correlation functions have become invaluable in revealing the precise dynamics of the strong interactions between a pair of hadrons, including meson-meson [43][44][45][46][47], meson-baryon [48][49][50], and (anti)baryon-(anti)baryon [51][52][53][54][55][56][57][58][59][60][61][62][63][64][65] interactions.…”