Baryon emission at target rapidities in Si+Al,Cu,Au collisions at 14.6AGeV/c and Au+Au collisions at 11.7AGeV/c

Abstract

We report measurements of proton emission at target rapidities for minimum bias and central collisions of $14.6A\mathrm{GeV}/c$ ${}^{28}\mathrm{Si}$ with Al, Cu, and Au nuclei as well as minimum bias and central collisions of $11.7A\mathrm{GeV}/c$ ${}^{197}\mathrm{Au}$ with Au nuclei. Results for deuteron emission are also reported for the $\mathrm{S}\mathrm{i}+\mathrm{A}\mathrm{u}$ reaction. The spectra span the laboratory angular range of $50\ifmmode^\circ\else\textdegree\fi{}<~\ensuremath{\theta}<~130\ifmmode^\circ\else\textdegree\fi{}$ and kinetic energy range of $40\mathrm{MeV}<~{E}_{\mathrm{kin}}<~225\mathrm{MeV}.$ Inverse slopes of proton spectra and proton $dN/d\ensuremath{\eta}$ values in the kinetic energy range $50\mathrm{MeV}<~{E}_{\mathrm{kin}}<~110\mathrm{MeV}$ are reported. The inverse slopes are 40--80 MeV for the various systems, generally increasing with increasing pseudorapidity. The $dN/d\ensuremath{\eta}$ values for $A+A$ collisions within the restricted kinetic energy interval are compared to those for protons from $p+\mathrm{Au}$ in the literature. All pseudorapidity distributions have very similar shapes. The experimental results have been compared to the predictions of the nucleon-nucleon collision models ARC and RQMD. The predictions made by these two models for the distribution of protons at target rapidities are very similar to each other. However, there are significant differences between the model predictions and the experimental results in the details of the spectral slopes and the proton yields for different trigger conditions.