## Abstract

The charged-Higgs-boson contributions to the Wilson coefficients C _{7} and C_{8}, relevant for the decay B → X _{sγ}, are discussed in supersymmetric models at large tanβ. These contributions receive two-loop O(α, tanβ) corrections by squark-gluino subloops, which are possibly large and nondecoupling in the limit of heavy superpartners. In previous studies, the relevant two-loop Feynman integrals were approximated by using an effective two-Higgs-doublet lagrangian. However, this approximation is theoretically justified only when the typical supersymmetric scale M_{SUSY} is sufficiently larger than the electroweak scale m_{weak} ∼ (m_{w}, m_{t}) and the mass of the chargcd-Higgs boson m_{H}±. Here, we evaluate these two-loop integrals exactly and compare the results with the existing, approximated ones. We then examine the validity of this approximation beyond the region where it has been derived, i.e. for m_{H} ≳ MSUSY and/or MSUSY ∼ m_{weak}.

Original language | English |
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Pages (from-to) | S483-S488 |

Journal | Journal of the Korean Physical Society |

Volume | 45 |

Issue number | 2 SUPPL. |

Publication status | Published - 2004 Nov 1 |

## Keywords

- B meson decay
- Supersymmetry

## ASJC Scopus subject areas

- Physics and Astronomy(all)