Photoproduction of $K^+K^-$ meson pairs on the proton

Abstract

The exclusive reaction $\gamma p \to p K^+ K^-$ was studied in the photon energy range 3.0−3.8 GeV and momentum transfer range $0.6<−t<1.3$ GeV$^2$. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. In this kinematic range the integrated luminosity was approximately 20 pb$^{−1}$. The reaction was isolated by detecting the K$^+$ and the proton in CLAS, and reconstructing the K$^−$ via the missing-mass technique. Moments of the di-kaon decay angular distributions were extracted from the experimental data. Besides the dominant contribution of the ϕ meson in the P-wave, evidence for S−P interference was found. The differential production cross sections dσ/dt for individual waves in the mass range of the ϕ resonance were extracted and compared to predictions of a Regge-inspired model. This is the first time the t-dependent cross section of the S-wave contribution to the elastic $K^+K^-$ photoproduction has been measured.