Backward-angle photoproduction of $\ddot{I}{€}^0$ mesons on the proton at $E_{\hat{I}}^3$ = 1.5--2.4 GeV

Abstract

Differential cross sections and photon beam asymmetries for $\ddot{I}{€}^0$ photoproduction have been measured at $E_{\hat{I}}^3$ = 1.5--2.4 GeV and at the $\ddot{I}{€}^0$ scattering angles, --1 $<$ cos$\hat{I}{˜}_{c.m.}<$ --0.6. The energy-dependent slope of differential cross sections for $u$-channel $\ddot{I}{€}^0$ production has been determined. An enhancement at backward angles is found above $E_{\hat{I}}^3$ = 2.0 GeV. This is inferred to be due to the $u$-channel contribution and/or resonances. Photon beam asymmetries have been obtained for the first time at backward angles. A strong angular dependence has been found at $E_{\hat{I}}^3>$ 2.0 GeV, which may be due to the unknown high-mass resonances.

12 pages, 4 figures, submitted to PLB