Near-threshold $K^*(892)^+$ meson production in the interaction of $π^-$ mesons with nuclei

Abstract

We study the inclusive strange vector meson K * (892) + production in π − A reactions at near-threshold laboratory incident pion momenta of 1.4-2.0 GeV/c within a nuclear spectral function approach. The approach accounts for incoherent primary π − meson-proton π − p → K * (892) + Σ − production processes as well as the influence of the scalar K * (892) +nucleus potential (or the K * (892) + in-medium mass shift) on these processes. We calculate the absolute differential and total cross sections for the production of K * (892) + mesons off carbon and tungsten nuclei at laboratory angles of 0 • -45 • and at these momenta within five scenarios for the above shift. We show that the K * (892) + momentum distributions and their excitation functions (absolute and relative) possess a high sensitivity to changes in the inmedium K * (892) + mass shift in the low-momentum region of 0.1-0.6 GeV/c. Therefore, the measurement of such observables in a dedicated experiment at the GSI pion beam facility in the near-threshold momentum domain will allow to get valuable information on the K * (892) + in-medium properties.