Anomalous J/ψ suppression in In-In collisions at 158 GeV/nucleon

J/psi suppression has been studied by the NA60 experiment in Indium-Indium collisions. A new analysis technique, based only on the J/psi sample, allows to accurately study the centrality dependence of J/psi production. The observed pattern indicates that a suppression is already present in In-In collisions, setting in at similar to 90 participant nucleons. A comparison with the available theoretical models is also presented.