Constraining the charged Higgs mass in the left-right symmetric model from b → sγ

In the context of the left-right symmetric model, the decay b → sγ receives contributions from the gauge interactions mediated mainly by the WL, through WL-WR mixing and also from the Yukawa interactions of the charged and the neutral (flavour-changing) scalars (the latter type of Yukawa interaction has been overlooked in the previous literature). Following the recent CLEO measurement of the inclusive b → sγ process and the measurement of the top-quark mass by the CDF and D0 collaborations, the parameter space of the left-right symmetric model is more squeezed than before.