Implications of $b\to s\gamma$ decay measurements in testing the MSSM Higgs sector

Abstract

The observation that the $b\to s\gamma$ decay rate is close to the Standard Model value implies a large mass for the charged-Higgs boson in the Minimum Supersymmetric Standard Model, that nearly closes the $t\to b{H}^{+}$ decay channel. For $m_t=150$ GeV, the parameter region $m_A\text{ltap}130$ GeV is excluded; this largely pre-empts LEP II searches and also partially excludes a region that would be inaccessible to MSSM Higgs boson searches both at LEP II and at SSC/LHC.

Comments: 8 pages + 3 PS figures not included (available upon request), MAD/PH/730