K−−pandK−−nCross Sections in the Momentum Range 1-4 Bev/c

Abstract

The energy dependence of the ${K}^{\ensuremath{-}}$-nucleon total cross sections has been measured over the ${K}^{\ensuremath{-}}$ momentum range 0.98-3.98 Bev/c. ${K}^{\ensuremath{-}}\ensuremath{-}n$ cross sections were obtained by deuterium-hydrogen subtraction, with a correction for screening effects. There is evidence for structure in the $T=0$ ${K}^{\ensuremath{-}}$-nucleon state in the momentum range 0.98-2.0 Bev/c. This structure is absent in the $T=1$ state. In addition, a measurement was made at 1.95 Bev/c of the angular distribution of the ${K}^{\ensuremath{-}}\ensuremath{-}p$ elastic scattering at small angles. The forward-scattering amplitude obtained from the data gives a ratio of real part to imaginary part 0.5\ifmmode\pm\else\textpm\fi{}0.2 at ${0}^{0}$. The corresponding ratio for ${\ensuremath{\pi}}^{\ensuremath{-}}$ mesons at this momentum was found to be ${0.4}_{\ensuremath{-}0.4}^{+0.2}$.Measurements of the ${K}^{\ensuremath{-}}\ensuremath{-}p$ "elastic" charge exchange gives a cross section which falls from about 10 mb at 1 Bev/c to at most a few mb at 4 Bev/c.