Production of \(\Sigma\) Baryons in p–Pb and pp Collisions at the LHC with ALICE

Abstract

During the LHC Run 2 several methods to identify charged \(\Sigma\) have been developed by ALICE. The main challenge of \(\Sigma\) measurements is the reconstruction of (anti-)neutrons, neutral mesons and soft photons produced in the decays using the electromagnetic calorimeter and photon conversion method. A novel method to detect anti-neutrons in the Photon Spectrometer (PHOS) was proposed, allowing the \(\bar{\Sigma}^{\pm}\rightarrow\bar{n}\pi^{\pm}\) decays to be reconstructed. We present the transverse momentum spectra of \(\bar{\Sigma}^{\pm}\) in minimum bias pp and p–Pb collisions at \(\sqrt{s}=5.02\) TeV compared with predictions from state-of-the-art Monte Carlo models. Also, results related to \(\Sigma^{+}\rightarrow p\pi^{0}\) and \(\Sigma^{0}\rightarrow\gamma\Lambda\) spectra and integrated yields measurements in Run 2 are presented.