1303.3338 (Hirosato Ono et al.)

On the effect of secondary protons on baryon and proton number cumulants
in event-by-event analysis    [PDF]

Hirosato Ono, Masayuki Asakawa, Masakiyo Kitazawa

We investigate the effects of secondary (knockout) protons, which constitute about 20% of the observed protons at STAR, on the higher order cumulants of proton and baryon numbers measured by event-by-event analyses in relativistic heavy ion collisions. We argue that the contribution of this background effect on the cumulants is expressed by a simple formula, and that hence their effects can be removed in the experimental analysis. It is discussed that this background effect has non-negligible contribution to recently observed proton number cumulants at STAR, especially the third-order one, and that the removal of this effect is crucial to investigate the thermodynamical properties of the primordial hot medium appropriately.

View original: http://arxiv.org/abs/1303.3338