Tensor Polarization of the phi meson Photoproduced at High t

Abstract

As part of a measurement of the cross section of $\ddot{I}•$ meson photoproduction to high momentum transfer, we measured the polar angular decay distribution of the outgoing $K^{+}$ in the channel $\ddot{I}•\to K^{+}{K}^{-}$ in the $\ddot{I}•$ center-of-mass frame (the helicity frame). We find that s-channel helicity conservation (SCHC) holds in the kinematical range where $t$-channel exchange dominates (up to $-t\sim 2.5$ GeV${}^2$ for $E_{\hat{I}}^3$=3.6 GeV). Above this momentum, $u$-channel production of a $\ddot{I}•$ meson dominates and induces a violation of SCHC. The deduced value of the $\ddot{I}•NN$ coupling constant lies in the upper range of previously reported values.

6 pages; 5 figures