(K-,K+) reaction on nuclear targets at PK = 1.65 GeV/c

The forward-angle cross sections of the (K-, K+) reaction on nuclear targets of C, Al, Cu, Ag and Pb have been measured at the K- incident momentum of 1.65 GeV/c in a wide range of K+ momentum. The obtained K+ momentum spectrum for each target nucleus is characterized by a peak in the high-momentum region (pK+ > 0.95 GeV/c) and a broad bump in the low-momentum region (pK+ < 0.95 GeV/c). A comparison of the measured spectrum with a DWIA calculation indicates that the quasifree process, K-(p)→ K+Ξ-, is dominant in the high-momentum region. The target mass-number dependence of the cross section is well fitted with Aα, where α is 0.38 ± 0.03 for the high-momentum region and 0.56 ± 0.02 for the low-momentum region. The result indicates that the quasifree process takes place at the peripheral of the target nucleus, whereas the two-step processes are dominant in the low-momentum region. (orig.)