Charge-Exchange Cross Section of 175- to 250-MevK+in Carbon, Copper, Tungsten, and Nuclear Emulsion

Abstract

The disappearance and presumed charge exchange of $K^{+}$ mesons has previously been observed in nuclear emulsions. We have measured the charge-exchange cross section for $K^{+}$ energies between 150 and 250 Mev in C, Cu, W, and, as a check, in nuclear emulsion. In addition, a scintillation-counter array was used to detect the charged decay mode of the short-lived ${K_1}^0$ produced in the charge-exchange reaction. The measured mean free path in nuclear emulsion is 195±25 cm at 200 Mev. The average corrected free-neutron cross section deduced from the pure elements is 5.9±0.4 mb.