Measurement of the p-Σ+ correlation function in pp collisions at √s=13 TeV

Abstract

In this letter, the first measurement of the femtoscopic correlation of protons and Sigma(+) hyperons is presented and used to study the p-Sigma(+) interaction. The measurement is performed with the ALICE detector in high-multiplicity triggered pp collisions at root s = 13 TeV. The Sigma(+) hyperons are reconstructed using a missing-mass approach in the decay channel to p + pi(0) with pi(0) -> gamma gamma, while both Sigma(+) and protons are identified using a machine learning approach. These techniques result in a high reconstruction efficiency and purity, which allows the measurement of the p-Sigma(+) correlation function for the first time. Thanks to the high significance achieved in the p-Sigma(+) correlation signal, it is possible to discriminate between the predictions of different models of the N-Sigma interaction and to accomplish a first determination of the p-Sigma(+) scattering parameters.