Abstract
The photoproduction of -mesic has been investigated using the TAPS calorimeter at the Mainz Microtron accelerator facility MAMI. The total inclusive cross section for the reaction has been measured for photon energies from threshold to 820 MeV. The total and angular differential coherent cross sections have been extracted up to energies of 745 MeV. A resonancelike structure just above the production threshold with an isotropic angular distribution suggests the existence of a resonant quasibound state. This is supported by studies of a competing decay channel of such a quasibound -mesic nucleus into . A binding energy of and a width of ( is deduced for the quasibound -mesic state in .
- Received 11 December 2003
DOI:https://doi.org/10.1103/PhysRevLett.92.252001
©2004 American Physical Society