https://doi.org/10.1140/epjc/s2005-02326-6
Experimental Physics
Can
mesons give an answer to the baryon puzzle at RHIC?
Received:
11
March
2005
Revised:
13
May
2005
Published online:
8
July
2005
The PHENIX experiment at RHIC has observed a large enhancement of baryon and anti-baryon production at 2-5 GeV/c, compared to expectations from jet fragmentation. While a number of theoretical interpretations of the data are available, there is not yet a definitive answer to the "baryon puzzle". We investigate the centrality dependence of
-meson production at mid-rapidity in Au + Au collisions with
GeV. Comparison with the proton and anti-proton spectra reveal similar shapes, as expected for soft production described by hydrodynamics. However, the absolute yields show a different centrality dependence. The nuclear modification factors for
are similar to those of pions, rather than (anti)protons that have similar mass. At intermediate , baryon/meson effects seem to be more important than the mass effects, in support of recombination models.
© Springer-Verlag, 2005