Parity Violation in Proton-Proton Scattering at 221 MeV

The parity-violating longitudinal analyzing power, Az, has been measured in →pp elastic scattering at an incident proton energy of 221 MeV. The result obtained is ${A}z{{0ex}{0ex}}={{0ex}{0ex}}[0.84±{}0.29(stat)±{}0.17(syst)]×{}{10}^{{-}7}$. This experiment is unique in that it selects a single parity violating transition amplitude ${(}³{P}₂¹{-}D₂)$ and consequently directly constrains the weak meson-nucleon coupling constant ${h}_{{ρ}}ᵖᵖ$. When this result is taken together with the existing ${{→}}{p}p$ parity violation data, the weak meson-nucleon coupling constants ${h}_{{ρ}}ᵖᵖ$ and ${h}_{{ω}}ᵖᵖ$ can, for the first time, both be determined.