(K⁻, K⁺) reaction on nuclear targets at P_K = 1.65 G

Abstract

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 side range K⁺ momentum. The obtained K⁺ momentum spectrum for each target nucleus is characterized by a peak in the high-momentum region (p_K⁺ > 0.95 GeV/c) and a broad bump in the low-momentum region (p_K⁺ < 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 A^α, 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.