Latest results of hadronic resonance production with ALICE at the LHC

Abstract

Resonances with very short lifetimes can be used to probe the rescattering and regeneration processes in the hadronic phase of the system produced after a high-energy collisions. These processes are studied by measuring resonance yields as a function of the system size and collision energy and comparing them to model calculations with and without the hadronic cascades. We present measurements of transverse momentum spectra, integrated yields (dN/dy), mean transverse momenta (〈pT〉), and angular distributions for light flavor hadronic resonances in pp, p–Pb, Xe–Xe, and Pb–Pb collisions at LHC energies. The 〈pT〉 of resonances as a function of event multiplicity in central Pb–Pb collisions follow the same mass ordering as for other hadrons, expected from the hydrodynamic expansion of the system. At high pT (> 8 GeV/c), nuclear modification factor (RAA) of light flavor hadrons in central Pb–Pb collisions shows strong suppression, whereas the nuclear modification factor in p–Pb collisions, known as RpPb is consistent with unity. This parton energy loss effect is independent of the particle species. Further, in non-central heavy-ion collisions, the vector mesons can be polarized due to spin-orbital-angular-momentum interaction or hadronization from polarized quarks due to their significant initial angular momentum. Recent measurements of spin alignment for K0 and φ mesons produced at midrapidity in pp and Pb–Pb collisions are discussed.