Evidence for a parity doublet Delta(1920)P33 and Delta(1940)D33 from gammap-->ppi;{0}eta

Phys Rev Lett. 2008 Nov 14;101(20):202002. doi: 10.1103/PhysRevLett.101.202002. Epub 2008 Nov 12.

Abstract

Evidence is reported for the existence of a parity doublet of Delta resonances with total angular momentum J=3/2 from photoproduction of the ppi;{0}eta final state. The two parity partners Delta(1920)P33 and Delta(1940)D33 make significant contributions to the reaction. Cascades of resonances into Delta(1232)eta, N(1535)pi, and Na0(980) are clearly observed.