Netprotonnumber kurtosis and skewness in nuclear collisions: Influence of deuteron formation
Abstract
We explore the influence of deuteron formation in the late stage of nucleusnucleus reactions on the fluctuations observed in the final netproton yields around midrapidity. At each investigated energy, the produced (anti)proton yield at chemical freezeout is assumed to fluctuate according to a Poisson distribution and in each event the probability for deuteron formation by coalescence is proportional to (d^{Nproton/d y ) 2}. The protons that are then clustered in deuterons are usually not included in the experimental measurement of the netproton fluctuations, therefore, we subtract these clustered protons from the final state proton number for the calculation of the netproton fluctuations (the same is done in the antiproton sector). Due to the nonlinear deuteron formation probability the resulting distribution is not a Skellam distribution, but shows the interesting feature of a decrease in the kurtosis κ σ^{2} and a local maximum in the skewness S σ observables as the collision energy decreases.
 Publication:

Physical Review C
 Pub Date:
 December 2015
 DOI:
 10.1103/PhysRevC.92.064908
 arXiv:
 arXiv:1510.05519
 Bibcode:
 2015PhRvC..92f4908F
 Keywords:

 25.75.q;
 24.60.k;
 Relativistic heavyion collisions;
 Statistical theory and fluctuations;
 Nuclear Theory;
 Nuclear Experiment
 EPrint:
 5 pages, 5 figures