Energy scan of correlations in p+p and Be+Be from NA61/SHINE

TL;DR

This paper reports on the NA61/SHINE experiment's energy scan of correlations in p+p and Be+Be collisions, aiming to explore the QCD phase diagram and search for the critical point through two-particle and long-range correlation studies.

Contribution

It presents new correlation measurements in p+p and Be+Be collisions at SPS energies, including the first results on multiplicity and transverse momentum correlations in Be+Be interactions.

Findings

Energy dependence of two-particle correlations in p+p collisions analyzed.

First measurements of multiplicity and mean transverse momentum correlations in Be+Be collisions.

Comparison of experimental data with EPOS 1.99 model predictions.

Abstract

The existence of the critical point (CP) of strongly interacting matter is still an open problem. An extensive strong interactions program including a search of the CP and the study of the onset of deconfinement was started by the NA61/SHINE experiment at the CERN SPS. A two dimensional scan of the phase diagram scan is performed to search for the CP and to shed light on the phase transition region. This program includes studies of hadron production in proton-proton, proton-nucleus and nucleus-nucleus interactions measured in a wide range of colliding energy and system size. Correlations between various observables measured at midrapidity as well as in separated rapidity intervals are considered as additional and sensitive tools of this phase diagram scan. We present NA61/SHINE results of studies of energy dependence of two-particle correlations of pseudo-rapidity and azimuthal angle in p+p collisions at the SPS and the first results on correlations between multiplicity and mean transverse momentum in 7Be+9Be collisions at 150A GeV/c obtained for separated pseudo-rapidity intervals (so called long-range correlations). Comparison with data calculations using the EPOS 1.99 model are also discussed.