Revealing baryon number fluctuations from proton number fluctuations in   relativistic heavy ion collisions
  Baryon number cumulants are invaluable tools to diagnose the primordial stage of heavy ion collisions if they can be measured. In experiments, however, proton number cumulants have been measured as substitutes. In fact, proton number fluctuations are further modified in the hadron phase and different from those of baryon number. We show that the isospin distribution of nucleons at kinetic freezeout is binomial and factorized. This leads to formulas that express the baryon number cumulants sorely in terms of proron number fluctuations, which are experimentally observable. 
Masakiyo Kitazawa and Masayuki Asakawa
nucl-th hep-ph nucl-ex