Gluon penguin enhancements to inclusive charmless decays of b quark in the2HDM with flavor changing couplings

We calculate the enhancements to the inclusive charmless decays of b quark, b --> sg, sq sq(q) over bar, sgg, from gluon penguin diagrams induced by t he charged and neutral Higgs bosons (H+/-, h(0), H-0, and A(0)) in the Two- Higgs-Doublet Model with flavor-changing couplings. Within the considered p arameter space, the new contributions from charged Higgs boson are dominant . After including the new contributions, the branching ratio BR(b --> sg) ( q(2) = 0) can be increased form similar to 0.2% in the standard model to 4. 4% and 2.6% in the two-Higgs-doublet model for m(H+) = 100 and 200 GeV, res pectively. The new contribution to the decay mode b --> sq sq(q) over bar w ith q = (u,d,s) is, however, numerically small and peaked at the lower q(2) region. The new contribution to b --> sgg can also be neglected. (C) 2000 Published by Elsevier Science B.V. All rights reserved.