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Related papers: NNLO QCD corrections to the B -> X_s gamma matrix …

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We compute the order 1/m_b^3 nonperturbative contributions to the inclusive differential B\to X_c\ell\bar\nu decay rate. They are parametrized by the expectation values of two local and four nonlocal dimension-six operators. We use our…

High Energy Physics - Phenomenology · Physics 2011-01-27 Martin Gremm , Anton Kapustin

We determine the chiral corrections to the matrix elements of the Delta B=0 four-quark operators which are relevant to the studies of the ratios of lifetimes of heavy-light mesons as well as to the power corrections to the inclusive…

High Energy Physics - Phenomenology · Physics 2009-01-16 Damir Becirevic , Svjetlana Fajfer , Jernej F. Kamenik

We present O(alpha_s^2) corrections to the decay t-->bW in the limit of a very large top quark mass, m_t >> m_W. We find that the O(alpha_s^2) effects decrease the top quark decay width Gamma_t by about 2%: Gamma_t =…

High Energy Physics - Phenomenology · Physics 2009-10-31 Andrzej Czarnecki , Kirill Melnikov

The $B_c(^1S_0)$ meson to S-wave Charmonia transition form factors are calculated in next-to-leading order(NLO) accuracy of Quantum Chromodynamics(QCD). Our results indicate that the higher order corrections to these form factors are…

High Energy Physics - Phenomenology · Physics 2015-05-27 Cong-Feng Qiao , Peng Sun , Feng Yuan

We compute the O(\alpha_s^2) corrections to the differential rate of the semileptonic decay b -> clv at the "intermediate recoil" point, where the c-quark mass and the invariant mass of the leptons are equal. The calculation is based on an…

High Energy Physics - Phenomenology · Physics 2008-11-26 Matthew Dowling , Alexey Pak , Andrzej Czarnecki

Using the renormalon calculus, we study the asymptotic behavior of the perturbative expansion of the hard-scattering kernels entering the QCD factorization formula for the nonleptonic weak decays B->D M, where M is a light meson. In the…

High Energy Physics - Phenomenology · Physics 2016-09-06 Thomas Becher , Matthias Neubert , Ben D. Pecjak

In a recent work, we calculated all three-loop diagrams contributing to the decay amplitude for $b \to s \gamma$ where none of the gluons touch the $b$-leg. In the present paper, we complete the calculation by working out all remaining…

High Energy Physics - Phenomenology · Physics 2024-10-22 Christoph Greub , Hrachia M. Asatrian , Hrachya H. Asatryan , Lukas Born , Julian Eicher

We evaluate the complete four-loop anomalous dimension matrix that is necessary for determining the effective flavour-changing neutral current couplings qbar-q'-gamma and qbar-q'-g at the next-to-next-to-leading order in QCD. The resulting…

High Energy Physics - Phenomenology · Physics 2010-10-27 Michal Czakon , Ulrich Haisch , Mikolaj Misiak

Short-distance expansion of the total semileptonic B widths is reviewed for the OPE-conformable scheme employing low-scale running quark masses. The third- and fourth-order BLM corrections are given and the complete resummation of the BLM…

High Energy Physics - Phenomenology · Physics 2009-11-07 Nikolai Uraltsev

We present our results of lattice calculations of $B$ parameters, which parameterize $\Delta B$=2 transition amplitudes together with the leptonic decay constant. Calculations are made in the quenched approximation at $\beta$=5.7, 5.9, 6.0…

We calculate nonperturbative ${\cal O}(\Lambda^2_{QCD}/m^2_c)$ corrections to the dilepton invariant mass spectrum and the forward-backward charge asymmetry in $B\to X_se^+e^-$ decay using a heavy quark expansion approach. The method has…

High Energy Physics - Phenomenology · Physics 2016-09-06 G. Buchalla , G. Isidori , S. -J. Rey

The asymptotic structure of the QCD perturbative relation between the on-shell and $\overline{\rm{MS}}$ heavy quark masses is studied. We estimate the five and six-loop contributions to this relation by three different techniques. First,…

High Energy Physics - Phenomenology · Physics 2020-12-01 A. L. Kataev , V. S. Molokoedov

In this paper the next-to-leading order (NLO) corrections to $B_c$ meson exclusive decays to S-wave charmonia and light pseudoscalar or vector mesons, i.e. $\pi$, $K$, $\rho$, and $K^*$, are performed within non-relativistic (NR) QCD…

High Energy Physics - Phenomenology · Physics 2014-02-12 Cong-Feng Qiao , Peng Sun , Deshan Yang , Rui-Lin Zhu

We use QCD sum rules to compute matrix elements of the Delta B=2 operators appearing in the heavy-quark expansion of the width difference of the B_s mass eigenstates. Our analysis includes the leading-order operators Q and Q_S, as well as…

High Energy Physics - Phenomenology · Physics 2007-05-23 T. Mannel , B. D. Pecjak , A. A. Pivovarov

In this paper, we calculate the next-to-next-to-leading-order (NNLO) QCD corrections to $e^+e^- \to J/\psi+\eta_c$ at the $B$ factories. After including the NNLO corrections, the cross section of $e^+e^- \to J/\psi+\eta_c$ is enhanced by…

High Energy Physics - Phenomenology · Physics 2023-02-08 Xu-Dong Huang , Bin Gong , Jian-Xiong Wang

Chirally enhanced supersymmetric QCD corrections to FCNC processes are investigated in the framework of the MSSM with generic sources of flavor violation. These corrections arise from flavor-changing self-energy diagrams and can be absorbed…

High Energy Physics - Phenomenology · Physics 2015-03-13 Andreas Crivellin , Ulrich Nierste

We present an updated next-to-leading order analysis of the B -> X_s gamma branching ratio and photon spectrum, including consistently the effects of Fermi motion in the heavy-quark expansion. For the Standard Model, we obtain B(B -> X_s…

High Energy Physics - Phenomenology · Physics 2011-09-13 A. L. Kagan , M. Neubert

We deduce the gluino contribution to the three-loop QCD \beta function within the minimal supersymmetric Standard Model (MSSM) from its standard QCD expression. The result is a first step in the computation of the full MSSM three-loop \beta…

High Energy Physics - Phenomenology · Physics 2009-10-30 L. Clavelli , P. W. Coulter , L. R. Surguladze

The leading order coefficients of the beta-function of QCD are computed in a large N_f expansion. They are in agreement with the three loop MSbar calculation. The method involves computing the anomalous dimension of the operator (G^2_{mu…

High Energy Physics - Phenomenology · Physics 2009-10-28 J. A. Gracey

We calculate the O(alpha_s) corrections to the double differential decay width dGamma_{77}/(ds_1 ds_2) for the process B -> X_s gamma gamma originating from diagrams involving the electromagnetic dipole operator O_7. The kinematical…

High Energy Physics - Phenomenology · Physics 2014-06-11 H. M Asatrian , C. Greub