On the two-loop sbottom corrections to the neutral Higgs boson masses in the MSSM Original Research Article

We compute the O(αbαs) two-loop corrections to the neutral Higgs boson masses in the Minimal Supersymmetric Standard Model, using the effective potential approach. Such corrections can be important in the region of parameter space corresponding to tanβ⪢1 and sizeable μ. In spite of the formal analogy with the O(αtαs) corrections, there are important differences, since the dominant effects are controlled by the sbottom-Higgs scalar couplings. We propose a convenient renormalization scheme that avoids unphysically large threshold effects associated with the bottom mass, and absorbs the bulk of the O(αbαs+αbαt) corrections into the one-loop expression. We give general explicit formulae for the O(αbαs) corrections to the neutral Higgs boson mass matrix. We also discuss the importance of the O(αb2) corrections and derive a formula for their contribution to mh in a simple limiting case.