A study of the (ωπ[sup ±]π[sup ∓]) state, where ω→π[sup +]π[sup −]π[sup 0] in the reaction π[sup −]p→π[sup +]π[sup +]π[sup −]π[sup −]π[sup 0]n at 18 GeV/c

Abstract

This study is based on a subset of events of the type π+π+π−π−γγ, from the π−p interaction in the 1995 run of E852, A Search for Mesons with Unusual Quantum Numbers at the MPS facility of BNL. The data set is reduced such that it contains events of the type ωπ−π+ to be used in the Partial Wave Analysis (PWA) of the system. In the ωπ± and the 4π mass spectra, we observe b1(1235) and ρ3(1690) signals. In the π−π+ off of the ω we see a large contribution due to ρ(770) followed by a smaller contribution due to f2(1270). The b1∓ production seems to be enhanced for the ωπ−π+ mass near 2 GeV, with more b1− produced than b1+. A spin parity analysis of the ωπ−π+ system to look for radial excitations and states with exotic quantum numbers is under way.