Remark on statistical model fits to particle ratios in relativistic heavy ion collisions

Abstract

In order to determine the chemical freeze-out parameters of the hadron-emitting source in relativistic heavy ion collisions some studies in literature perform fits by using as data input a subsample of ratios calculated out of experimentally measured hadron yields instead of yields themselves. We show that this is a statistically incorrect method fit, implying a bias in the extracted parameters.

Comments: 6 pages, 2 figures. Few changes in the text