Nuclear Stopping in $\mathrm{A}\mathrm{u}+\mathrm{A}\mathrm{u}$ Collisions at $\sqrt{s_{NN}}=200\mathrm{G}\mathrm{e}\mathrm{V}$

Transverse momentum spectra and rapidity densities, $dN/dy$, of protons, antiprotons, and net protons ($p-\overline{p}$) from central (0%–5%) $\mathrm{A}\mathrm{u}+\mathrm{A}\mathrm{u}$ collisions at $\sqrt{s_{NN}}=200\mathrm{G}\mathrm{e}\mathrm{V}$ were measured with the BRAHMS experiment within the rapidity range $0\le y\le 3$. The proton and antiproton $dN/dy$ decrease from midrapidity to $y=3$. The net-proton yield is roughly constant for $y<1$ at $dN/dy\sim 7$, and increases to $dN/dy\sim 12$ at $y\sim 3$. The data show that collisions at this energy exhibit a high degree of transparency and that the linear scaling of rapidity loss with rapidity observed at lower energies is broken. The energy loss per participant nucleon is estimated to be $73\pm 6\mathrm{G}\mathrm{e}\mathrm{V}$.