Experimental determination of elastic and topological cross sections in 48.9-GeV/cp¯pinteractions

The elastic and topological $\overline{p}p$ cross sections have been measured at 48.9 GeV/c in the Fermilab proportional-wire-chamber-30-in.-bubble-chamber hybrid spectrometer. The elastic cross section is 7.81±0.24 mb and the slope of the elastic differential cross section at $t=0\mathrm{}$ is 13.4±0.8 ${\mathrm{GeV}}^{-2\mathrm{}}$. Further, the moments of the inelastic topological-cross-section distribution are $〈n_c〉=5.69\mathrm{}\pm 0.03$, $\frac{〈n_c〉}{D}=2.10\mathrm{}\pm 0.02$, and $f_2^{\mathrm{cc}}=1.67\mathrm{}\pm 0.12$.