Measuring the $\varphi$ meson width in the medium from $p$ induced $\varphi$ production in nuclei

Abstract

We study the $A$ dependence of the $\varphi$ meson production cross section in proton nucleus reactios at energies just above threshold, which are accessible in an experimental facility like COSY. This $A$ dependence has two sources: the distortion of the incident proton and the absorption of the $\varphi$ in its way out of the nucleus. This second process reduces the cross section in about a factor two in heavy nuclei. Thus we show that the $A$ dependence of the cross section contains valuable information on the $\varphi$ width in the nuclear medium.

Comments: 4 pages, 2 figures, Talk presented at the 10th International Conference on the Structure of Baryons "Baryons 2004", Ecole Polytechnique, Palaiseau, France, October 25 - 29, 2004