K*(892)0andϕ(1020)production in Pb-Pb collisions at

B. I. Abelev¹,

J. Adam²,

D. Adamová³

et al.

Abstract

The yields of the k'*(892)° and 0( 1020) resonances are measured in Pb-Pb collisions at y/sNN = 2.76 TeV through their hadronic decays using the ALICE detector. The measurements are performed in multiple centrality intervals at mid-rapidity (|y| < 0.5) in the transverse-momentum ranges 0.3 < pT < 5 GeV/c for the 7C(892)° and0.5 < pr < 5 GeV/c for the 0(1020). The yields of A/*(892)° are suppressed in central Pb-Pb collisions with respect to pp and peripheral Pb-Pb collisions (perhaps due to rescattering of its decay products in the hadronic medium), while the longer-lived <p( 1020) meson is not suppressed. These particles are also used as probes to study the mechanisms of particle production. The shape of the pT distribution of the 0(1020) meson, but not its yield, is reproduced fairly well by hydrodynamic models for central Pb-Pb collisions. In central Pb-Pb colhsions at low and intermediate p j, the p /0 ( 1020) ratio is flat in p j, while the p /n and 0 (lO2O)/7r ratios show a pronounced increase and have similar shapes to each other. These results indicate that the shapes of the pT distributions of these particles in central Pb-Pb collisions are determined predominantly by the particle masses and radial flow. Finally, 0(1020) production in Pb-Pb collisions is enhanced, with respect to the yield in pp collisions and the yield of charged pions, by an amount similar to the A and S.

Elliptic flow of identified hadrons in Pb-Pb collisions at s N N = 2.76 $$ \sqrt{s_{\mathrm{NN}}}=2.76 $$ TeV

“…For peripheral collisions though, the v 2 values of the φ-meson shift progressively to the band of mesons. This is congruous with the observation that the (p+p)/φ ratio, calculated from the transverse momentum spectra, is almost constant as a function of transverse momentum in central Pb-Pb events, while for peripheral collisions the ratio decreases with increasing p T , as reported in [79].Finally, the multi-strange baryons, i.e. Ξ − +Ξ + and Ω − +Ω + , provide another interesting test of both the mass ordering and the baryon-meson grouping.…”

Centrality dependence of the nuclear modification factor of charged pions, kaons, and protons in Pb-Pb collisions atsNN=2.76TeV

“…In Ref. [68] ALICE showed calculations for such a model [31] and the prediction is that at the LHC energies the particle ratios in central collisions are similar to those measured at the highest RHIC energy. In hard recombination models, jet fragments can recombine with both partons from the medium and other jets.…”

“…As the φ meson has a mass similar to that of a proton, it is crucial in testing these ideas and results at the RHIC indeed seemed to confirm this picture [67], while at LHC the picture appears to be more complicated [68,69]. Some of the models developed to describe results at the RHIC have been extended to the LHC energies.…”

Particle production at energies available at the CERN Large Hadron Collider within an evolutionary model

“…As for the large deviation in the case of the K * /K ch ratio, it can be explained by different definitions of the K * /K ch ratio in the experiment and iHKM from the one side and the thermal model calculations from the other side. As follows from the experimental papers, e.g., [30], the K * 0 (892) resonances are reconstructed via the products of their decay into K + π − pairs with branching ratio 0.66 (while the K * 0 's decaying through a channel K * 0 → K 0 π 0 are excluded from the analysis). The same reconstruction procedure is applied in the iHKM study.…”