$b \to s γ$ Decay in $SU(2)_L \times SU(2)_R \times U(1)$ Extensions of the Standard Model

The rare radiative decay $b \to s \gamma$ is studied in $SU(2)_L \times SU(2)_R \times U(1)$ extensions of the Standard Model. Matching conditions for coefficients of operators appearing in the low energy effective Hamiltonian for this process are derived, and QCD corrections to these coefficients are analyzed. The $b \to s \gamma$ decay rate is then calculated and compared with the corresponding Standard Model result. We find that observable deviations from Standard Model predictions can occur in $SU(2)_L \times SU(2)_R \times U(1)$ theories for a reasonable range of parameter values.