The Search for a π1(1400) Exotic Meson in the γp → Δ++ηπ- System with CLAS

Several experiments have reported evidence for the pi(1)(1400) using pion production but the results have been controversial and its existence has yet to be seen in photoproduction. Theoretical works have implied that the production amplitude will be greatly increased in photoproduction in comparison to the pion production. The reaction gamma p -> Delta X++ -> p pi(+)pi(-)(eta) is being studied in the photon energy range 4.4 to 5.4 GeV as a possible method of producing the pi(1)(1400) resonance. Data were collected at Jefferson Lab in Hall B. This reaction is being investigated by detecting the p pi(+)pi(-)2 gamma and reconstructing the eta through the missing-mass of the p pi(+)pi(-), and comparing the results to the 2 gamma composite. These data have yielded a(0)(980) and a(2)(1320) in the pi(-)eta invariant mass spectrum. Further analysis is needed to untangle the possible pi(1)(1400) resonance from the a(2)(1320).