We present the QCD corrections to R(b) and to the Delta B = 1 effective Hamiltonian in models with a second Higgs field that couples to the quarks respecting the criterion of minimal flavor violation, thus belonging either to the (1, 2)(1/2) or to the (8, 2)(1/2) representation of SU(3) x SU(2) x U(1). After the inclusion of the QCD corrections, the prediction for R(b) becomes practically insensitive to the choice of renormalization scheme for the top mass, which for the type-I and type-II models translates in a more robust lower bound on tan beta. The QCD-corrected determinations of R(b) and BR(B -> X(s)gamma) are used to discuss the constraints on the couplings of a (colored) charged Higgs boson to top and bottom quarks.
Degrassi, G., Slavich, P. (2010). QCD corrections in two-Higgs-doublet extensions of the standard model with minimal flavor violation. PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY, 81(7) [10.1103/PhysRevD.81.075001].
QCD corrections in two-Higgs-doublet extensions of the standard model with minimal flavor violation
DEGRASSI, GIUSEPPE;
2010-01-01
Abstract
We present the QCD corrections to R(b) and to the Delta B = 1 effective Hamiltonian in models with a second Higgs field that couples to the quarks respecting the criterion of minimal flavor violation, thus belonging either to the (1, 2)(1/2) or to the (8, 2)(1/2) representation of SU(3) x SU(2) x U(1). After the inclusion of the QCD corrections, the prediction for R(b) becomes practically insensitive to the choice of renormalization scheme for the top mass, which for the type-I and type-II models translates in a more robust lower bound on tan beta. The QCD-corrected determinations of R(b) and BR(B -> X(s)gamma) are used to discuss the constraints on the couplings of a (colored) charged Higgs boson to top and bottom quarks.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.