$\overline{\Sigma }^{\pm }$ production in $\text {pp}$ and $\text {p}{-}\text {Pb}$ collisions at $\sqrt{s_{\textrm{NN}}} = 5.02$ TeV with ALICE

The transverse momentum spectra and integrated yields of anti- $$\Sigma $$ Σ hyperons ( $$\overline{\Sigma }^{\pm } $$ Σ ¯ ± ) have been measured in $$\text {pp}$$ pp and $$\text {p}{-}\text {Pb}$$ p - Pb collisions at $$\sqrt{s_{\textrm{NN}}}=5.02$$ s NN = 5.02 TeV with the ALICE experiment. Measurements are performed via the newly accessed decay channel $$\overline{\Sigma }^{\pm } \!\!\rightarrow \mathrm{\overline{n}} \pi ^{\pm }$$ Σ ¯ ± → n ¯ π ± . A new method of antineutron reconstruction with the PHOS electromagnetic spectrometer is developed and applied to this analysis. The $$p_{\textrm{T}}$$ p T spectra of $$\overline{\Sigma }^{\pm } $$ Σ ¯ ± are measured in the range $$0.5<p_{\textrm{T}} <3$$ 0.5 < p T < 3 GeV/ $$c$$ c and compared to predictions of the PYTHIA 8, DPMJET, PHOJET, EPOS LHC and EPOS4 models. The EPOS LHC and EPOS4 models provide the best descriptions of the measured spectra both in $$\text {pp}$$ pp and $$\text {p}{-}\text {Pb}$$ p - Pb collisions, while models which do not account for multiparton interactions provide a considerably worse description at high $$p_{\textrm{T}}$$ p T . The total yields of $$\overline{\Sigma }^{\pm } $$ Σ ¯ ± in both $$\text {pp}$$ pp and $$\text {p}{-}\text {Pb}$$ p - Pb collisions are compared to predictions of the Thermal-FIST model and dynamical models PYTHIA 8, DPMJET, PHOJET, EPOS LHC and EPOS4. All models reproduce the total yields in both colliding systems within uncertainties. The nuclear modification factors $$R_\textrm{pPb}$$ R pPb for both $$\overline{\Sigma }^{+} $$ Σ ¯ + and $$\overline{\Sigma }^{-} $$ Σ ¯ - are evaluated and compared to those of protons, $$\Lambda $$ Λ and $$\Xi $$ Ξ hyperons, and predictions of EPOS LHC and EPOS4 models. No deviations of $$R_\textrm{pPb}$$ R pPb for $$\overline{\Sigma }^{\pm } $$ Σ ¯ ± from the model predictions or measurements for other hadrons are found within uncertainties.