The production of K *(892)(0) and phi(1020) mesons in proton-proton (pp) and lead-lead (Pb-Pb) collisions at root s(NN) = 5.02 TeV has been measured using the ALICE detector at the Large Hadron Collider (LHC). The transverse momentum (p(T)) distributions of K*(892)(0) and phi(1020) mesons have been measured at midrapidity (vertical bar y vertical bar < 0.5) up to p(T) = 20 GeV/c in inelastic pp collisions and for several Pb-Pb collision centralities. The collision centrality and collision energy dependence of the average transverse momenta agree with the radial flow scenario observed with stable hadrons, showing that the effect is stronger for more central collisions and higher collision energies. The K*(0)/K ratio is found to be suppressed in Pb-Pb collisions relative to pp collisions: this indicates a loss of the measured K *(892)(0) signal due to rescattering of its decay products in the hadronic phase. In contrast, for the longer-lived phi(1020) mesons, no such suppression is observed. The nuclear modification factors (R-AA) of K*(892)(0) and phi(1020) mesons are calculated using pp reference spectra at the same collision energy. In central Pb-Pb collisions for p(T) > 8 GeV/c, the R-AA values of K *(892)(0) and phi(1020) are below unity and observed to be similar to those of pions, kaons, and (anti)protons. The R-AA values at high pT (>8 GeV/c) for K*(892)0 and f(1020) mesons are in agreement within uncertainties for root s(NN) = 5.02 and 2.76 TeV.
Production of and in collisions at
G. Bonomi;R. Lea;D. Pagano;M. Urioni;N. Zurlo
2022-01-01
Abstract
The production of K *(892)(0) and phi(1020) mesons in proton-proton (pp) and lead-lead (Pb-Pb) collisions at root s(NN) = 5.02 TeV has been measured using the ALICE detector at the Large Hadron Collider (LHC). The transverse momentum (p(T)) distributions of K*(892)(0) and phi(1020) mesons have been measured at midrapidity (vertical bar y vertical bar < 0.5) up to p(T) = 20 GeV/c in inelastic pp collisions and for several Pb-Pb collision centralities. The collision centrality and collision energy dependence of the average transverse momenta agree with the radial flow scenario observed with stable hadrons, showing that the effect is stronger for more central collisions and higher collision energies. The K*(0)/K ratio is found to be suppressed in Pb-Pb collisions relative to pp collisions: this indicates a loss of the measured K *(892)(0) signal due to rescattering of its decay products in the hadronic phase. In contrast, for the longer-lived phi(1020) mesons, no such suppression is observed. The nuclear modification factors (R-AA) of K*(892)(0) and phi(1020) mesons are calculated using pp reference spectra at the same collision energy. In central Pb-Pb collisions for p(T) > 8 GeV/c, the R-AA values of K *(892)(0) and phi(1020) are below unity and observed to be similar to those of pions, kaons, and (anti)protons. The R-AA values at high pT (>8 GeV/c) for K*(892)0 and f(1020) mesons are in agreement within uncertainties for root s(NN) = 5.02 and 2.76 TeV.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.