Evidence for I=1 (A1) and I=0 (H) Axial-Vector Resonances in Charge Exchange

Abstract

Results are presented from an isobar-model partial-wave analysis of a high-statistics sample of the neutral $3\pi$ system produced in forward charge exchange. Large forward phase motions relative to an exotic reference wave are seen for partial waves with the quantum numbers of the $A_1$ and of the previously unobserved isoscalar companion ($``H\text{'}\text{'}$) of the $B\left(1235\right)\mathrm{}$.