QCD Corrections to $b \to s \gamma$ Decay in 2-Higgs Doublet Model

Abstract

We give a more complete calculation of $b \to s\gamma $ decay in 2-Higgs doublet model, including leading log QCD corrections from $m_{top}$ to $M_W$ in addition to corrections from $M_{W}$ to $m_b$. The inclusive decay rate in the first model is found to be suppressed 23\% comparing with the calculations without the QCD running from $m_{top}$ to $M_W$. And the enhancement up to 5\% is found in calculations of the second model. More strict restrictions to parameters of 2-Higgs doublet model II are found.