Measurements of $\hat{I}{ž}^{-}$ and $\overline{\hat{I}}{ž}^{+}$ production in proton-proton interactions at $\sqrt{s_{NN}}$ = 17.3 GeV in the NA61/SHINE experiment

Abstract

The production of $\hat{I}ž(1321{)}^{-}$ and $\overline{\hat{I}}ž(1321{)}^{+}$ hyperons in inelastic p+p interactions is studied in a fixed target experiment at a beam momentum of 158 GeV/textit{c}. Double differential distributions in rapidity y and transverse momentum $p_T$ are obtained from a sample of 33M inelastic events. They allow to extrapolate the spectra to full phase space and to determine the mean multiplicity of both $\hat{I}{ž}^{-}$ and $\overline{\hat{I}}{ž}^{+}$. The rapidity and transverse momentum spectra are compared to transport model predictions. The $\hat{I}{ž}^{-}$ mean multiplicity in inelastic p+p interactions at 158~\GeVc is used to quantify the strangeness enhancement in A+A collisions at the same centre-of-mass energy per nucleon pair.