$K^{\pm}$ p elastic scattering at 5 GeV/c evidence for a $K^{-}p$ backward peak

The elastic scattering of K/sup +or-/ mesons on protons has been studied at 5 GeV/c. A total of about 500000 events have been measured in the c.m. angular range 17 degrees < theta /sub cm/<165 degrees corresponding to 0.2<-t<(GeV/c)/sup 2/. The authors observe a K/sup - /p backward peak which they have parametrized as d sigma /du= (0.6+or-0.2) exp ((3.3+or-0.6)u) mu b/GeV/c)/sup 2/, while for the K /sup +/p backward peak they find d sigma /du=(17.5+or-1)exp ((3.6+or-0.2)u) mu b/(GeV/c)/sup 2/. The K/sup -/p cross-section falls into about 0.03 mu b/(GeV/c)/sup 2/ around -t=5 (GeV/c)/sup 2/, while the K/sup +/p cross-section stays in the vicinity of 0.2 mu b(GeV/c) /sup 2/ in the same t-region. The K/sup +/p and K/sup -/p differential cross-sections have cross-over points at -t=0.2, 1.1 and about 3.5 (Ge V/c)/sup 2/. (11 refs)