Orateur
Description
Short-lived resonances are ideal probes to study the properties of the hadron gas phase created in heavy-ion collisions in the post-hadronization phase. Since the resonance lifetime is comparable to that of the hadron gas phase, their yields are affected by the competing rescattering and regeneration effects. These can be studied experimentally by measuring the yield ratios of resonances to the corresponding long-lived hadrons as a function of the charged-particle multiplicity, which is a proxy of the system volume. In this context, the $\rho^{0}(770)$ resonance is particularly interesting due to its very short lifetime of about 1.3 fm/$c$. The measurement of the $\rho^{0}(770)$ production yield in low-multiplicity collisions, corresponding to a very short duration of the hadron gas phase, serves as a fundamental reference for measurements in heavy-ion collisions.
In this poster, recent measurements of the $\rho(770)^{0}$ production in pp collisions with the ALICE detector as a function of multiplicity are presented. The results are discussed together with existing measurements in other collision systems in the context of the state-of-the-art phenomenological models used to describe particle production at LHC energy.
