Speakers
Description
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 ($\mathrm{d}N/\mathrm{d}y$), mean transverse momenta ($\langle {p}_\mathrm{T} \rangle$), and angular distributions for light flavour hadronic resonances in pp, p--Pb, Xe--Xe, and Pb--Pb collisions at LHC energies.
The $\langle {p}_\mathrm{T} \rangle$ 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 $p_\mathrm{T}$ ($>$ 8 GeV/$c$), nuclear modification factor ($R_\mathrm{AA}$) of light flavor hadrons in central Pb--Pb collisions shows strong suppression, whereas the nuclear modification factor in p--Pb collisions, known as $R_{\mathrm{pPb}}$ 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 $K^{∗0}$ and $\phi$ mesons produced at midrapidity in pp and Pb--Pb collisions will be presented.