Search for structure in the low-energyp¯pannihilation cross section

Abstract

Relative cross sections have been measured for $\overline{p}p$ annihilation by a new technique in the invariant-mass range 1920-1960 MeV. The 90%-confidence upper limit on simple Breit-Wigner enhancements in the $S$ region (between 1930 and 1942 MeV) of width 4 MeV or narrower is 12 mb MeV, assuming a simple dependence with momentum of the nonresonant cross section.