We study the properties of the B → π and B → K transition form factors in partially quenched QCD by using the approach of partially quenched chiral perturbation theory combined with the static heavy quark limit. We show that the form factors change almost linearly when varying the value of the sea quark mass, whereas the dependence on the valence quark mass contains both the standard and chiral...

We calculate the dominant contributions of third generation four-quark operators to single-Higgs production and decay. They enter via loop corrections Higgs decays into gluons, photons $b\bar{b}$, in gluon fusion association with top quark pairs. show that these effects can, some cases, lead better constraints than those from fits data. Finally, we investigate whether four-fermion can spoil det...

We studied the properties of MSSM Higgs bosons, h and H through decay into b-quarks in associated production with a top-quark pair. There was used tree-level sector described by two parameters M$_A$ tan$\beta$ found their optimal values according to experimental data ATLAS detector. Using restricted parameter space we calculated cross sections $t\bar{t}h(H)$ at 13 14 TeV, corresponding kinemati...

We explore the transitions B(0 +) to B π and Bs(0 +) to B K from lattice QCD with N f = 2 flavours of sea quark, using the static approximation for the heavy quark. We evaluate the effective coupling constants, predicting a B(0 +) to B π width of around 160 MeV. Our result for the coupling strength adds to the evidence that the Bs(0 +) meson is not predominantly a molecular state (BK).

We calculate threshold soft-gluon corrections to total cross sections and transverse momentum distributions for bottom and charm quark production in fixed-target experiments, considering both pp and π−p interactions. We investigate the quality of the near threshold soft-gluon approximation at next-to-leading order (NLO) and calculate next-to-nextto-leading order (NNLO) corrections through next-...

Assuming one nonzero product of two λ-type couplings and working in two different bases for the left-handed quark superfields, the neutral meson mixings are used to bound these products. We emphasize the strong basis dependence of the bounds: in one basis many products contribute to neutral meson mixings at tree level, while in the other these products except one contribute at 1-loop level only...

We present the first 30 moments of the low energy expansions of the vector, axialvector, scalar and pseudo-scalar heavy quark correlation functions at three-loop order, including the singlet contribution which appears for the first time at three loops. In addition we compare the behavior of the moments for large n with the prediction from threshold calculations.

We calculate the soft contribution to high energy quark-quark scattering that arises from an instanton-induced quark anomalous chromomagnetic moment. We demonstrate that this is a large contribution, which cannot be neglected for transverse momenta of a few GeV. We discuss the influence of this effect on inclusive particle production. [email protected]

A method to extract B-physics parameters (b-quark mass and fB, fBs decay constants) from currently available lattice data is presented and tested. The approach is based on the idea of constructing appropriate ratios of heavy-light meson masses and decay constants, respectively, possessing a precisely known static limit, and evaluating them at various pairs of heavy quark masses around the charm...

We give explicit formulae for the anomalous chromomagnetic dipole moment of the top quark in the framework of the standard model, the two higgs doublet model and the minimal supersymmetric standard model. Finally, we compare the results for this coupling with the bound −0.03 ≤ ∆κ ≤ 0.01 coming from analysis of b → sγ process whith an on-shell gluon. The top quark is the heaviest fermion in the ...