Related papers: Quark mass effects in B -> Xs gamma
We present a precise lattice QCD determination of the b-quark mass, of the B and Bs decay constants and first results for the B-meson bag parameters. For our computation we employ the so-called ratio method and our results benefit from the…
We give the explicit wave functions of the $qqqq\bar{q}$ components of the C=+1, J=1/2 charmed baryons, $\Sigma_{c}$, $\Lambda_{c}$ and $\Xi_{c}^{a}$, and calculate the magnetic moments by adding the 5q components contributions, and we also…
In this contribution the QCD next-to-next-to-leading order (NNLO) matching coefficients to the branching ratio $B_s \to \mu^+ \mu^-$ in the Standard Model (SM) and to $\bar{B}\to X_s \gamma$ in the Two Higgs Doublet Model (2HDM) are…
We provide a new determination of the charm quark mass using the Highly Improved Staggered Quark (HISQ) action, finding m_c(3 GeV) = 0.983(23) GeV. Our determination makes extensive use of second order lattice perturbation theory in…
We present a new QCD sum rule with high sensitivity to the continuum regions of charm and bottom quark pair production. Combining this sum rule with existing ones yields very stable results for the MS-bar quark masses, m_c(m_c) and…
We study the effects of the one-loop matching conditions on Higgs boson and top quark masses on the triviality bounds on the Higgs boson mass using $\beta_{\lambda}$ with corrected two-loop coefficients. We obtain quite higher results than…
We determine the charm-quark mass mc(mc) in the MS-bar scheme using measurements of charm production in deep-inelastic ep scattering at HERA in the kinematic range of photon virtuality from 5 to 1000 GeV squared and Bjorken scaling variable…
The charm quark's mass is determined from Monte Carlo calculations of the $\bar{c}c$ spectrum. The main sources of uncertainty are perturbation theory (for conversion to $\MSbar$), the continuum-limit extrapolation, Monte Carlo statistics,…
We compute the two-loop QCD corrections to the neutral Higgs-boson masses in the MSSM, including the effect of non-vanishing external momenta in the self-energies. We obtain corrections of O(alpha_t*alpha_s) and O(alpha*alpha_s), i.e., all…
We present quantitative results on the cross section for $\gamma + \gamma (J_z=0) \to b \bar{b}\to two b$-jets based on the recently achieved all orders resummation of large soft (Sudakov) and hard (non-Sudakov) double logarithms. The…
This paper investigates the influence of heavy-quark momentum on their interaction rate and the resulting drag coefficient in a quark-gluon plasma. To go beyond simplified treatments, we introduce a phenomenological extension of the drag…
Threshold-state elementary particle lifetimes exhibit a scaling in powers of alpha = e^2/hslash*c, and a reciprocal electron-based 1/alpha scaling in particle masses that extends over two powers of 1/alpha. The m(e)/alpha coupling generates…
The calculation of the one-loop induced decay rate b -> s \gamma is improved by including radiative corrections to the charged Higgs mass and to the charged-Higgs-fermion-fermion vertex. It is shown how the radiative corrections modify the…
We use a four-dimensional lattice calculation of the full-QCD (quantum chromodynamics, the non-abliean gauge theory of the strong interactions of quarks and gluons) path integrals needed to determine the masses of the charmed and bottom…
We compute the two-loop electroweak corrections to the radiative decays of the B meson in the SM. Electroweak effects reduce the Wilson coefficient C_7^eff(mw) by 2.6% for a light Higgs boson of about 100 GeV and are less important for a…
The truncation of the perturbative series at one loop order for the mass renormalization constants remain a significant systematic uncertainty in the determination of heavy quark masses in lattice QCD. We present here a high beta Monte…
Rare $B$-meson decays, suppressed in the Standard Model (SM) by the GIM mechanism, are sensitive probes of new physics. In particular, loop-level $b \to s$ transitions can reveal effects of heavy virtual particles such as vector-like quarks…
In this work the charm and bottom quark masses are determined from QCD moment sum rules for the charmonium and upsilon systems. To illustrate the special character of these sum rules when applied to Coulomb systems we first set up and study…
One of the most troublesome contributions to the NNLO QCD corrections to B -> X_s gamma originates from three-loop matrix elements of four-quark operators. A part of this contribution that is proportional to the QCD beta-function…
We update our perturbative determination of MSbar bottom quark mass mb(mb), by including the recently obtained four-loop coefficient in the relation between the pole and MSbar mass. First the renormalon subtracted (RS or RS') mass is…