Statistical Power-Law Spectra due to Reservoir Fluctuations
  LHC ALICE data are interpreted in terms of statistical power-law tailed pT spectra. As explanation we derive such statistical distributions for particular particle number fluctuation patterns in a finite heat bath exactly, and for general thermodynamical systems in the subleading canonical expansion approximately. Our general result, $q = 1 - 1/C + \Delta T^2 / T^2$, demonstrates how the heat capacity and the temperature fluctuation effects compete, and cancel only in the standard Gaussian approximation. 
T.S. Bir\'o, G.G. Barnaf\"oldi, P. V\'an, K. \"Urm\"ossy
hep-ph cond-mat.stat-mech math.ST stat.TH