Comparison of<i>p</i>+<i>A</i>and Si+Au collisions at 14.6 GeV/<i>c</i>

Abstract

The production of ${\mathrm{\ensuremath{\pi}}}^{\ifmmode\pm\else\textpm\fi{}}$,${\mathit{K}}^{\ifmmode\pm\else\textpm\fi{}}$,p has been measured in p+Be and p+Au collisions for comparison with central Si+Au collisions. The inverse slope parameters ${\mathit{T}}_{0}$ obtained by an exponential fit to the invariant cross sections in transverse mass are found to be, ${\mathit{T}}_{0}^{\mathit{p},}$${\mathit{K}}^{+}$,${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{\pi}}}$\ensuremath{\sim}140--160 MeV in p+A collisions, whereas in central Si+Au collisions, ${\mathit{T}}_{0}^{\mathit{p},}$${\mathit{K}}^{+}$\ensuremath{\sim}200--220 MeV &gt;${\mathit{T}}_{0}^{\mathrm{\ensuremath{\pi}}\mathrm{\ensuremath{\pi}}}$\ensuremath{\sim}140--160 MeV at midrapidity. The ${\mathrm{\ensuremath{\pi}}}^{\ifmmode\pm\else\textpm\fi{}}$ and ${\mathit{K}}^{+}$ distributions are shifted backwards in p+Au compared with p+Be. A gradual increase of (dn/dy${)}_{\mathit{K}}^{+}$ per projectile nucleon is observed from p+Be to p+Au to central Si+Au collisions, while pions show no significant increase.