The production of 𝐾*(892)± meson resonance is measured at midrapidity (|𝑦|<0.5) in Pb−Pb collisions at √𝑠𝑁𝑁=5.02 TeV using the ALICE detector at the CERN Large Hadron Collider. The resonance is reconstructed via its hadronic decay channel 𝐾*(892)±→𝐾0 S𝜋±. The transverse momentum distributions are obtained for various centrality intervals in the 𝑝T range of 0.4−16 GeV/𝑐. Measurements of integrated yields, mean transverse momenta, and particle yield ratios are reported and found to be consistent with previous ALICE measurements for 𝐾*(892)0 within uncertainties. The 𝑝T-integrated yield ratio 2𝐾*(892)±/(𝐾++𝐾−) in central Pb−Pb collisions shows a significant suppression at a level of 9.3𝜎 relative to 𝑝𝑝 collisions. Thermal model calculations result in an overprediction of the particle yield ratio. Although both hadron resonance gas in partial chemical equilibrium (HRG-PCE) and music + smash simulations consider the hadronic phase, only HRG-PCE accurately represents the measurements, whereas music + smash simulations tend to overpredict the particle yield ratio. These observations, along with the kinetic freeze-out temperatures extracted from the yields measured for light-flavored hadrons using the HRG-PCE model, indicate a finite hadronic phase lifetime, which decreases with increasing collision centrality percentile. The 𝑝T-differential yield ratios 2𝐾*(892)±/(𝐾++𝐾−) and 2𝐾*(892)±/(𝜋++𝜋−) are presented and compared with measurements in pp collisions at √𝑠=5.02 TeV. Both particle ratios are found to be suppressed by up to a factor of five at 𝑝T<2.0 GeV/𝑐 in central Pb−Pb collisions and are qualitatively consistent with expectations for rescattering effects in the hadronic phase. The nuclear modification factor (𝑅AA) shows a smooth evolution with centrality and is found to be below unity at 𝑝T>8 GeV/𝑐, consistent with measurements for other light-flavored hadrons. The smallest values are observed in most central collisions, indicating larger energy loss of partons traversing the dense medium.
K*(892)± resonance production in Pb-Pb collisions at sNN=5.02 TeV
Barile, F.Membro del Collaboration Group
;Colella, D.Membro del Collaboration Group
;Di Bari, D.Membro del Collaboration Group
;Mazzilli, M.Membro del Collaboration Group
;Volpe, G.Membro del Collaboration Group
;
2024-01-01
Abstract
The production of 𝐾*(892)± meson resonance is measured at midrapidity (|𝑦|<0.5) in Pb−Pb collisions at √𝑠𝑁𝑁=5.02 TeV using the ALICE detector at the CERN Large Hadron Collider. The resonance is reconstructed via its hadronic decay channel 𝐾*(892)±→𝐾0 S𝜋±. The transverse momentum distributions are obtained for various centrality intervals in the 𝑝T range of 0.4−16 GeV/𝑐. Measurements of integrated yields, mean transverse momenta, and particle yield ratios are reported and found to be consistent with previous ALICE measurements for 𝐾*(892)0 within uncertainties. The 𝑝T-integrated yield ratio 2𝐾*(892)±/(𝐾++𝐾−) in central Pb−Pb collisions shows a significant suppression at a level of 9.3𝜎 relative to 𝑝𝑝 collisions. Thermal model calculations result in an overprediction of the particle yield ratio. Although both hadron resonance gas in partial chemical equilibrium (HRG-PCE) and music + smash simulations consider the hadronic phase, only HRG-PCE accurately represents the measurements, whereas music + smash simulations tend to overpredict the particle yield ratio. These observations, along with the kinetic freeze-out temperatures extracted from the yields measured for light-flavored hadrons using the HRG-PCE model, indicate a finite hadronic phase lifetime, which decreases with increasing collision centrality percentile. The 𝑝T-differential yield ratios 2𝐾*(892)±/(𝐾++𝐾−) and 2𝐾*(892)±/(𝜋++𝜋−) are presented and compared with measurements in pp collisions at √𝑠=5.02 TeV. Both particle ratios are found to be suppressed by up to a factor of five at 𝑝T<2.0 GeV/𝑐 in central Pb−Pb collisions and are qualitatively consistent with expectations for rescattering effects in the hadronic phase. The nuclear modification factor (𝑅AA) shows a smooth evolution with centrality and is found to be below unity at 𝑝T>8 GeV/𝑐, consistent with measurements for other light-flavored hadrons. The smallest values are observed in most central collisions, indicating larger energy loss of partons traversing the dense medium.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
