Possible Anisotropies in the Production and Decay Correlations of theη′(958)

Abstract

The spin and parity analysis of the ${\eta }^{\prime }\mathrm{}\left(958\right)\mathrm{}$ from the distribution of events on the ${\pi }^{+}{\pi }^{-}\eta$ and the ${\pi }^{+}{\pi }^{-}\gamma$ Dalitz plots has been shown to favor $J^P=0^{-}$ over $2^{-}$, but not conclusively. The Brookhaven National Laboratory-University of Michigan data reported here indicate anisotropies in the production and decay correlation angular distributions. Earlier Lawrence Berkeley Laboratory data dilute these effects. The observed anisotropies weaken the evidence for a $J^P=0^{-}$ assignment for the ${\eta }^{\prime }\mathrm{}\left(958\right)\mathrm{}$.