Scale dependence of mean transverse momentum fluctuations at 158 AGeV

Non-statistical event-by-event fluctuations of mean transverse momentum, pT , have been proposed as a possible signature for the QCD phase transition, in particular for the critical point. A surprising finding was that a small but practically beam energy independent value was found for the broad energy range of 40 AGeV SPS beam up to top RHIC energy [1]. On the other hand, the fluctuations seem to be a non-monotonic function of centrality [2].