Measurement of $Λ$(1520) production in pp collisions at $\sqrt{s}$ = 7 TeV and p-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV

Abstract

The production of the $Λ$(1520) baryonic resonance has been measured at midrapidity in inelastic pp collisions at $\sqrt{s}$ = 7 TeV and in p-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV for non-single diffractive events and in multiplicity classes. The resonance is reconstructed through its hadronic decay channel $Λ$(1520) $\rightarrow$ pK$^{-}$ and the charge conjugate with the ALICE detector. The integrated yields and mean transverse momenta are calculated from the measured transverse momentum distributions in pp and p-Pb collisions. The mean transverse momenta follow mass ordering as previously observed for other hyperons in the same collision systems. A Blast-Wave function constrained by other light hadrons ($π$, K, K$_{\rm{S}}^0$, p, $Λ$) describes the shape of the $Λ$(1520) transverse momentum distribution up to 3.5 GeV/$c$ in p-Pb collisions. In the framework of this model, this observation suggests that the $Λ(1520)$ resonance participates in the same collective radial flow as other light hadrons. The ratio of the yield of $Λ(1520)$ to the yield of the ground state particle $Λ$ remains constant as a function of charged-particle multiplicity, suggesting that there is no net effect of the hadronic phase in p-Pb collisions on the $Λ$(1520) yield.