Nuclear annihilation by antinucleons

Abstract

We examine the momentum dependence of $\bar{p}$$p$ and $\bar{n}$$p$ annihilation cross sections by considering the transmission through a nuclear potential and the $\bar{p}p$ Coulomb interaction. Compared to the $\bar{n}p$ annihilation cross section, the $\bar{p}p$ annihilation cross section is significantly enhanced by the Coulomb interaction for projectile momenta below $p_{\mathrm{lab}}<$ 500 MeV/$c$, and the two annihilation cross sections approach the Pomeranchuk's equality limit [JETP Lett. {\bb 30}, 423 (1956)] at $p_{\mathrm{lab}}\sim 500$ MeV/$c$. Using these elementary cross sections as the basic input data, the extended Glauber model is employed to evaluate the annihilation cross sections for $\bar{n}$ and $\bar{p}$ interaction with nuclei and the results compare well with experimental data.

Comments: 9 pages, 6 figures