Recent Results from the Strong Interaction Program of the NA61/SHINE Experiment and Physics Plans Beyond 2020

The NA61 / SHINE experiment at the CERN SPS studies hadron production properties in hadron-nucleus and nucleus-nucleus collisions. The experiment performs unique measurements for physics of strong interactions as well as important measurements for neutrino and cosmic-ray physics. Results from the strong interaction programme indicate a threshold for formation of large clusters interpreted as the onset of fireball. A scaled-factorial-moment analysis of the proton density fluctuations in Ar + Sc collisions at 150 A GeV = c shows an intermittency signal, which may be a first trace of critical behavior. The main objective of the future NA61 / SHINE program is to obtain high-precision data on charm hadron production. This new program is planed to start after 2020 and requires significant upgrades of the NA61 / SHINE detector setup. Besides the construction of a large accectance vertex detector, a 10-fold increase of the event recording rate is foreseen. plasma and the search for the predicted critical point. A scan of the phase diagram of strongly interacting matter was done by changing energy and size of the collision system (from p + p to Pb + Pb in the beam momentum range 13 A (cid:4) 150 A GeV = c ). Various observables, e.g. quantities measuring event-to-event fluctuations of the particle multiplicity, which are expected to reveal the occurrence of a phase transition or of critical behavior are examined. The experimental program has recently been extended by measurements of charm hadron production in nucleus-nucleus collisions, which are expected to provide an additional insight into the phase transition behavior of hadronic matter. For this purpose, a vertex detector was constructed to meet the challenges of open charm measurements.