Amplitude analysis of vector-pseudoscalar final states at GlueX

Abstract

Excited vector mesons, some of which are predicted to include gluonic excitation in their wavefunctions, and certain classes of axial vector mesons, some of which are implicated in the decay of spin-exotic mesons, decay dominantly to vector-pseudoscalar final states. In particular, the axial vector $b_1(1235)$ decays dominantly to $\omega\pi$, and is produced copiously at the GlueX experiment. It provides a testing ground to explore strategies for amplitude analysis of further vector-pseudoscalar channels where the intermediate resonances may be harder to isolate. The formalism for amplitude analysis of $b_1^-$ production via charge exchange with a recoiling $\Delta^{++}$ is presented here, and compared with the proton recoil case. A strategy for a systematic analysis of reactions involving $\Delta^{++}$ recoil is outlined.