Speaker
Description
In addition to $\Lambda$ hyperon, new data on $\Sigma$ hyperons production are compared to different Monte-Carlo models and contribute to the understanding of hadron production mechanisms.
The first measurements of the transverse momentum ($p_{\rm{T}}$) spectra of $\Sigma^{0}$ and $\bar{\Sigma}^{0}$ hyperons in pp collisions at $\sqrt{s} = 7$ TeV at the LHC are presented. The $\Sigma^{0}$($\bar{\Sigma}^{0}$) is reconstructed via its electromagnetic decay channel $\Lambda(\bar{\Lambda}) + \gamma$, while the $\Lambda$($\bar{\Lambda}$) baryon is detected via its decay into $p + \pi^{-}$ ($\bar{p}$ + $\pi^{+}$). The low-energy photon is measured via conversion into $e^{+}e^{-}$ pairs in the detector material and in PHOS calorimeter by exploiting the unique capability of the ALICE detector.
The complementary results on the first detection of $\Sigma^{+}$ and $\bar{\Sigma}^-$ hyperon at the LHC with ALICE are shown in pp collisions at $\sqrt{s} = 13$ TeV. The $\Sigma^{+}$($\bar{\Sigma}^-$) is reconstructed via its weak decay into p$(\overline{\rm{p}}) + \pi^0$ with the challenging detection of low-energy photons from $\pi^0$ decay.
Also, the first reconstruction and $p_{\rm{T}}$ spectra of the production of $\bar{\Sigma^{\pm}} \to \bar{\rm{n}} + \pi^{\pm}$ in pp and p-Pb collisions are presented. Antineutron is identified and reconstructed with PHOS by unique signature of the annihilation process.
