Combined Description of N‾N\bf{\overline{N}N} Scattering and Annihilation With A Hadronic Model

A model for the nucleon-antinucleon interaction is presented which is based on meson-baryon dynamics. The elastic part is the $G$-parity transform of the Bonn $NN$ potential. Annihilation into two mesons is described in terms of microscopic baryon-exchange processes including all possible combinations of $\pi,\eta,\rho,\omega,a_0,f_0,a_1,f_1,a_2,f_2,K,K^*$. The remaining annihilation part is taken into account by a phenomenological energy- and state independent optical potential of Gaussian form. The model enables a simultaneous description of nucleon-antinucleon scattering and annihilation phenomena with fair quality.Comment: revised version, REVTEX, 9 pages, 10 figures available from this URL ftp://ikp113.ikp.kfa-juelich.de/pub/kph140/nucl-th.9411014.u

Measurement of the n̄-Fe absorption cross section between 125 and 780 MeV/c

The n\u304-Fe absorption cross section sigma(nbarFe) has been measured at LEAR (the Low Energy Antiproton Ring at CERN) using tagged n\u304's produced in the p\u304p \u2192 n\u304n charge-exchange reaction. With incident p\u304 momenta of 875 and 545 MeV/c sigma(nbarFe) has been measured in the momentum interval between 125 and 780 MeV/c, in a region where only a few measurements presently exist. The overall statistical and systematic errors range from 20 to 5%; the normalisation error is less than 3%. The measured cross sections are well reproduced by a parametrisation a+b/p, with a = 0.680 \ub1 0.051 barn and b = 0.228 \ub1 0.024 barn\ub7GeV/c