Hadron Production in the Trans-fragmentation Region in Heavy-Ion Collisions

Abstract

We study the production of hadrons in Au+Au collisions in the region $0.6<x_F<1.2$, which we refer to as the trans-fragmentation region (TFR), since it corresponds roughly to ${\eta }^{\prime }>0$, where ${\eta }^{\prime }=\eta -y_{\mathrm{beam}}$, depending on $p_T$. We show how hadrons can be produced in that region when the hadronization process is parton recombination. The inclusive $x$-distributions for proton and pion production are calculated with momentum degradation taken into account. The results show that the proton yield is significantly higher than that of the pions in the TFR. Without particle identification the existing data cannot be used for comparison with our result on the $p/\pi$ ratio. Without $p_T$ determination it is not feasible to relate the $x$ distribution to the experimental ${\eta }^{\prime }$ distribution. Nevertheless, on theoretical grounds we have shown why the production of hadrons in the TFR is not forbidden by momentum conservation.

Comments: 23 pages in LaTeX + 6 figures in eps