Measurements of neutrons in $11.5A$ $\mathrm{GeV}/c$ $\mathrm{Au}+\mathrm{Pb}$ heavy-ion collisions

We present measurements from Brookhaven AGS Experiment 864 of neutron invariant multiplicity in $11.5A$ GeV/c $\mathrm{Au}+\mathrm{Pb}$ collisions. The measurements span a rapidity range from center of mass to beam rapidity ${(y}_{\mathrm{beam}}=3.2)$ and are presented as a function of event centrality. The results are compared with E864 measurements of proton invariant multiplicity and an average $n/p$ ratio at hadronic freeze-out of $1.19\pm .08$ is determined for the rapidity range $y=1.6\mathrm{}$ to $y=\mathrm{2.4.}\mathrm{}$ We discuss briefly the implications of this ratio within a simple equilibrium model of the collision system.