Parity Violation in Proton-Proton Scattering at 221 MeV

The parity-violating longitudinal analyzing power, $A_z$, has been measured in $\overrightarrow{p}p$ elastic scattering at an incident proton energy of 221 MeV. The result obtained is $A_z=[0.84\pm 0.29(\mathrm{stat})\pm 0.17(\mathrm{syst}\left)\right]\times {10}^{-7\mathrm{}}$. This experiment is unique in that it selects a single parity violating transition amplitude ${(}^3{P}_2{}_{}{}^1{}_{}{}^{}-D_2^{}{}_{}{}^{})$ and consequently directly constrains the weak meson-nucleon coupling constant $h_{\rho }^{\mathrm{pp}}$. When this result is taken together with the existing $\overrightarrow{p}p$ parity violation data, the weak meson-nucleon coupling constants $h_{\rho }^{\mathrm{pp}}$ and $h_{\omega }^{\mathrm{pp}}$ can, for the first time, both be determined.