Hadronic resonances in pp, p–Pb and Pb–Pb in ALICE

• Main Author: Bellini Francesca
• Format: Article
• Language: English
• Published: EDP Sciences 2015-01-01
• Series: EPJ Web of Conferences
• Online Access: http://dx.doi.org/10.1051/epjconf/20159700004

The production of hadronic resonances has been measured by the ALICE experiment at mid-rapidity in different collision systems (pp, p–Pb, and Pb–Pb). The measurements of K(892)*0 and ø(1020) production in Pb–Pb collisions at √sNN = 2.76 TeV and in pp at √s = 2.76 and 7 TeV are complemented by the more recent measurement in p–Pb collisions at √sNN = 5.02 TeV. The ratios of resonance to long lived hadron production in the three collision systems are compared in order to investigate re-scattering effects, which appear to be relevant for K*0 in the most central Pb–Pb collisions, while ø behaves instead like a long-lived particle. Resonance observables contribute to draw the picture of central Pb–Pb collisions as a hydrodynamics-driven system. The comparison of the ø/p and p/π ratios as a function of transverse momentum (pT) indicates that the mass of the particle determines the spectral shapes at low and intermediate pT in central Pb–Pb collisions. The mean transverse momentum, 〈pT〉, of K*0 and ø in central Pb–Pb collisions is consistent with that of the proton, which has similar mass. In pp and p–Pb collisions the 〈pT〉 of resonances does not follow mass ordering. The nuclear modification factors (RAA, RpA) of the ø meson are also discussed in comparison with those of the stable hadrons.