Impact of resonance regeneration and decay on the net-proton   fluctuations in a hadron resonance gas
  We investigate net-proton fluctuations as important observables measured in heavy-ion collisions within the hadron resonance gas (HRG) model. Special emphasis is given to effects which are a priori not inherent in a thermally and chemically equilibrated HRG approach. In particular, we point out the importance of taking into account the successive regeneration and decay of resonances below the chemical freeze-out, which lead to a randomization of the isospin of nucleons and thus to additional fluctuations in the net-proton number. We find good agreement between our model results and the recent STAR measurements of the higher-order moments of the net-proton distribution. 
Marlene Nahrgang, Marcus Bluhm, Paolo Alba, Rene Bellwied, Claudia   Ratti
hep-ph nucl-ex nucl-th