Measurement of the in-medium phi-meson width in proton-nucleus collisions

nucl-ex

/ Authors

A. Polyanskiy, M. Hartmann, Yu. T. Kiselev, E. Ya. Paryev, M. Buescher, D. Chiladze, S. Dymov, A. Dzyuba, R. Gebel, V. Hejny

and 18 more authors

B. Kaempfer, I. Keshelashvili, V. Koptev, B. Lorentz, Y. Maeda, S. Merzliakov, S. Mikirtytchiants, M. Nekipelov, H. Ohm, H. Schade, V. Serdyuk, A. Sibirtsev

/ Abstract

The production of phi mesons in the collisions of 2.83 GeV protons with C, Cu, Ag, and Au at forward angles has been measured via the phi -> K+K- decay using the COSY-ANKE magnetic spectrometer. The phi meson production cross section follows a target mass dependence of A^0.56+/-0.02 in the momentum region of 0.6-1.6 GeV/c. The comparison of the data with model calculations suggests that the in-medium phi width is about an order of magnitude larger than its free value.