English
Related papers

Related papers: Two-Loop Relations for Heavy-Quark Parameters in t…

200 papers

We determine the b-quark shape function parameters in the shape function scheme, m_b(SF) and \mu_\pi^2(SF), using the Belle B->X_s gamma photon energy spectrum. We assume three models for the form of the shape function; exponential,…

High Energy Physics - Experiment · Physics 2007-05-23 I. Bizjak , A. Limosani , T. Nozaki

We compute the two-loop term in the perturbation series for the quark-mass in the lattice Heavy Quark Effective Theory. This is an ingredient in the matching factor required to obtain the $b$-quark mass from lattice simulations of the HQET.…

High Energy Physics - Lattice · Physics 2009-10-09 G. Martinelli , C. T. Sachrajda

Masses of heavy Standard Model fermions (top-quark, bottom-quark, and tau-lepton) play an important role in the analysis of theories beyond the SM. They serve as low-energy input and reduce the parameter space of such theories. In this…

High Energy Physics - Phenomenology · Physics 2010-05-25 A. V. Bednyakov

We present a systematic study of the shape function for inclusive B-meson decays in the heavy-quark limit, which is based on the QCD equations of motion and heavy-quark symmetry, and takes into account the cusp divergence due to radiative…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hiroyuki Kawamura , Jiro Kodaira , Kazuhiro Tanaka

In the heavy-quark limit, the decay spectrum for radiative and semileptonic inclusive B-meson decays is determined by a universal structure function, i.e. the shape function. We study the constraints on the bilocal heavy-quark operator for…

High Energy Physics - Phenomenology · Physics 2009-11-10 Hiroyuki Kawamura , Jiro Kodaira , Kazuhiro Tanaka

We obtain new estimates for the parameters $\lambda_{E}^2$, $\lambda_H^2$ and their ratio $\mathcal{R} = \lambda_{E}^2/\lambda_H^2$, which appear in the second moments of the $B$-meson light-cone distribution amplitudes defined in the…

High Energy Physics - Phenomenology · Physics 2021-08-11 Muslem Rahimi , Marcel Wald

We discuss how one can determine the average kinetic energy of the heavy quark inside heavy mesons from differential distributions in $B$ decays. A new, so-called third, sum rule for the $b\rightarrow c$ transition is derived in the small…

High Energy Physics - Phenomenology · Physics 2009-10-28 I. Bigi , A. Grozin , M. Shifman , N. Uraltsev , A. Vainshtein

The running mass of the b-quark defined in DRbar-scheme is one of the important parameters of SUSY QCD. To find its value it should be related to some known experimental input. In this paper the b-quark running mass defined in…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. V. Bednyakov

Based on a new, exact QCD factorization formula for the partial B->X_s+gamma decay rate with a restriction on large photon energy, improved predictions are presented for the partial moments <E_gamma> and <E_gamma^2>-<E_gamma>^2 of the…

High Energy Physics - Phenomenology · Physics 2009-11-11 Matthias Neubert

The pseudoscalar sum rules of the heavy-light quark systems are used for extracting simultaneously the c,b quark masses and the decay constants f_D_(s),f_B_(s) of the D_(s),B_(s) mesons. To order alpha_s^2, one obtains the running quark…

High Energy Physics - Phenomenology · Physics 2008-11-26 Stephan Narison

We find that the anomalous dimension (in the $\bar{MS}$ scheme) of the chromo-magnetic operator $g_s\bar h_v\sigma_{\mu\nu} G^{\mu\nu} h_v$ in the heavy-quark effective theory is \gamma_{mag} = (C_A\alpha_s / 2\pi) [1 + ( 17/18 C_A - 13/18…

High Energy Physics - Phenomenology · Physics 2009-10-30 G. Amorós , M. Beneke , M. Neubert

We present a study of a combination of HQET and relativistic QCD to extract the b-quark mass and the Bs-meson decay constant from lattice quenched simulations. We start from a small volume, where one can directly simulate the b-quark, and…

High Energy Physics - Lattice · Physics 2008-01-02 Damiano Guazzini

The paper is devoted to the calculation of the two-loop O(alpha_s y^2) and O(y^4) MSSM corrections to the relation between the pole mass of the b-quark and its running mass in DR scheme. To evaluate the needed diagrams the large mass…

High Energy Physics - Phenomenology · Physics 2011-01-27 A. Bednyakov , A. Sheplyakov

We present exact results, at next-to-leading order in renormalization-group improved perturbation theory, for the Wilson coefficients appearing at order 1/m_Q in the heavy-quark expansion of heavy-light current operators. To this end, we…

High Energy Physics - Phenomenology · Physics 2009-10-31 Thomas Becher , Matthias Neubert , Alexey A. Petrov

Parameters of the heavy four-quark scalar meson $T_{\mathrm{bc\overline{b} \overline{c}}}$ with content $bc \overline{b}\overline{c}$ are calculated by means of the sum rule method. This structure is considered as a diquark-antidiquark…

High Energy Physics - Phenomenology · Physics 2024-09-27 S. S. Agaev , K. Azizi , H. Sundu

The running mass of the b quark as defined in the MS-bar renormalization scheme, m_b, was measured at the M_Z scale using 2.8 million hadronic Z^0 decays collected by the DELPHI experiment at LEP. The result is m_b(M_Z) = 2.67 +- 0.25…

High Energy Physics - Experiment · Physics 2011-01-27 S. Marti i Garcia , J. Fuster , S. cabrera

We present a fully non-perturbative computation of the mass of the b-quark in the quenched approximation. Our strategy starts from the matching of HQET to QCD in a finite volume and finally relates the quark mass to the spin averaged mass…

High Energy Physics - Phenomenology · Physics 2009-11-11 Michele Della Morte , Nicolas Garron , Mauro Papinutto , Rainer Sommer

We demonstrate that Borel QCD sum rules for heavy-light currents entail a very strong correlation between the $b$-quark mass $m_b$ and the $B$-meson decay constant $f_B,$ that is, $\delta f_B/f_B\approx-8\delta m_b/m_b.$ By starting from…

High Energy Physics - Phenomenology · Physics 2014-04-15 Wolfgang Lucha , Dmitri Melikhov , Silvano Simula

A shape-function independent relation is derived between the partial B->X_u+l+nu decay rate with a cut on P_+=E_X-P_X<Delta and a weighted integral over the normalized B->X_s+gamma photon-energy spectrum. The leading-power contribution to…

High Energy Physics - Phenomenology · Physics 2011-02-01 Bjorn O. Lange , Matthias Neubert , Gil Paz

We present expressions for shape variables of B decay distributions in several different mass schemes, to order $\alpha_s^2\beta_0$ and (Lambda_{QCD}/mb)^3. Such observables are sensitive to the b quark mass and matrix elements in the heavy…

High Energy Physics - Phenomenology · Physics 2008-11-26 Christian W. Bauer , Zoltan Ligeti , Michael Luke , Aneesh V. Manohar
‹ Prev 1 2 3 10 Next ›