Photoproduction of $\ddot{I}‰$ mesons on nuclei near the production threshold

Abstract

The photoproduction of $\ddot{I}‰$ mesons on LH_2, C and Nb has been studied for incident photon energies from 900 to 1300 MeV using the CB/TAPS detector at ELSA. The $\ddot{I}‰$ line shape does not show any significant difference between the LH_2 and the Nb targets. The data are compared with results of transport calculations that predict a sensitivity of the $\ddot{I}‰$ line shape to in-medium modifications near the production threshold on a free nucleon of $E_γ^{lab}$ = 1109 MeV.}

5 pages, 3 figures