Determination of theω0Spin—Density-Matrix Elements in the Reactionπ−p→ω0n

Abstract

We report measurements of the ${\ensuremath{\omega}}^{0}$ spin-density matrix elements in the reaction ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}{\ensuremath{\omega}}^{0}n$ at incident momenta of 3.65, 4.5, and 5.5 $\frac{\mathrm{GeV}}{c}$. In the Gottfried-Jackson frame the data exhibit nonzero values of ${\ensuremath{\rho}}_{00}$, indicating the presence of unnatural-parity exchange as well as a large value of ${\ensuremath{\rho}}_{11}+{\ensuremath{\rho}}_{1\ensuremath{-}1}$ which does not show a dip in the momentum transfer distribution. The unnatural-parity contribution decreases with respect to the natural-parity contribution as the momentum increases.