Experimental observation of type-B coherent photoproduction of e+e- pairs in a crystal
Avakyan R. O. , Avetisyan A. E., Gyurdzhyan V. A. , Dallakyan K. R. , Danagulyan S. S. , Darbinyan S. M. , Ispiryan K. A. , Kizogyan O. S. , Margaryan A. T. , Sukiasyan Yu. Z. , Taroyan S. P.
The energy dependence of the coherent production of e+e~ pairs in a crystal (diamond, (100)) has been measured for the first time at photon energies of 100-1000 MeV. The results confirm the existence of a type-B effect in this process.