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Related papers: Kinetic corrections to B -> X_c l nu at one loop

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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

Making use of conformal symmetry of large-$n_f$ QCD in $d=4-2\epsilon$ dimensions at the Wilson-Fischer fixed point, we calculate the two-loop coefficient functions in the operator product expansion of two electromagnetic currents in…

High Energy Physics - Phenomenology · Physics 2024-11-25 Vladimir M. Braun , Hua-Yu Jiang , Alexander N. Manashov , Andreas von Manteuffel

We calculate the two-loop QCD correction to the form factors of on-shell b-quark decay to an energetic massless quark, which constitutes the last missing piece required for an O(alpha_s^2) determination of |V_ub| from inclusive…

High Energy Physics - Phenomenology · Physics 2014-11-18 M. Beneke , T. Huber , Xin-Qiang Li

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

Quantum chromodynamics (QCD) effects in the semileptonic decay b -> c l nu are evaluated to the second order in the coupling constant, O(alpha_s^2), and to several orders in the expansion in quark masses, m_c/m_b. Corrections are calculated…

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

We present our results for the NNLL virtual corrections to the matrix elements of the operators O_1 and O_2 for the inclusive process b\to s\ell^+\ell^- in the kinematical region q^2>4m_c^2, where q^2 is the invariant mass squared of the…

High Energy Physics - Phenomenology · Physics 2009-05-20 Christoph Greub , Volker Pilipp , Christof Schüpbach

We compute the O(alpha_s) corrections to the Wilson coefficients of the dimension five operators emerging from the Operator Product Expansion of inclusive radiative B decays. We discuss the impact of the resulting O(alpha_s…

High Energy Physics - Phenomenology · Physics 2010-02-15 Thorsten Ewerth , Paolo Gambino , Soumitra Nandi

We evaluate the electromagnetic spectral function in QCD plasma in a nonperturbative background of in-medium quark and gluon condensates by incorporating the leading order power corrections in a systematic framework within the ambit of the…

High Energy Physics - Phenomenology · Physics 2016-12-21 Aritra Bandyopadhyay , Munshi G Mustafa

We compute 2-loop QCD corrections to the hard coefficient functions which arise in the factorization formula for B -> X_u l nu decays in the shape-function region. Our calculation provides the last missing piece required for a NNLO analysis…

High Energy Physics - Phenomenology · Physics 2009-02-23 Guido Bell

We study the effect of dimension 7 and 8 operators on inclusive semileptonic B decays and the extraction of |Vcb|. Using moments of semileptonic B decay spectra and information based on the Lowest-Lying State saturation Approximation (LLSA)…

High Energy Physics - Phenomenology · Physics 2016-10-19 Paolo Gambino , Kristopher J. Healey , Sascha Turczyk

We carry out the one-loop calculation of mass dependent ${\cal O}(a)$ improvement coefficients in the relativistic heavy quark action recently proposed, employing the ordinary perturbation theory with the fictitious gluon mass as an…

High Energy Physics - Lattice · Physics 2015-06-25 Sinya Aoki , Yasuhisa Kayaba , Yoshinobu Kuramashi

These lectures describe in detail the effective Hamiltonians for weak decays of mesons constructed by means of the operator product expansion and the renormalization group method. We calculate Wilson coeffcients of local operators, discuss…

High Energy Physics - Phenomenology · Physics 2007-05-23 Andrzej J. Buras

We present a complete $O(\alpha_s^2)$ correction to the differential width of the inclusive semileptonic decay $b\to cl\nu_l$ at the kinematical point of vanishing invariant mass of the leptons, $q^2=0$. Together with the recently computed…

High Energy Physics - Phenomenology · Physics 2014-11-17 Andrzej Czarnecki , Kirill Melnikov

Recently, it was shown that in inclusive B -> Xs l+ l- decay, an angular decomposition provides three independent (q^2 dependent) observables. A strategy was formulated to extract all measurable Wilson coefficients in B -> Xs l+ l- from a…

High Energy Physics - Phenomenology · Physics 2009-08-03 Keith S. M. Lee , Frank J. Tackmann

We reduce the perturbative uncertainty in the determination of |V_{ub}| from inclusive semileptonic B decays by calculating the rate of B -> X_u l nu events with dilepton invariant mass q^2>(M_B-M_D)^2 at subleading order in the hybrid…

High Energy Physics - Phenomenology · Physics 2014-11-17 Matthias Neubert , Thomas Becher

We investigate new-physics contributions to $b\to s \ell\ell$ transitions in the context of an effective field theory extension of the Standard Model, including operator mixing at one loop. We identify the few scenarios where a single…

High Energy Physics - Phenomenology · Physics 2020-02-19 Rupert Coy , Michele Frigerio , Federico Mescia , Olcyr Sumensari

The renormalon calculus is used to calculate the terms of order $\beta_0^{n-1}\alpha_s^n$ in the perturbative expansions of the Wilson coefficients and hard-scattering kernels entering the QCD factorization formula for hadronic B-meson…

High Energy Physics - Phenomenology · Physics 2009-11-07 Matthias Neubert , Ben D. Pecjak

I present one-loop level calculations of the Isgur-Wise functions for B -> D^{(*)} + e + nu, of the matrix elements of isovector twist-2 operators in B and D mesons, and the matrix elements for the radiative decays D^* -> D + gamma in…

High Energy Physics - Phenomenology · Physics 2009-11-07 Martin J. Savage

In this paper we compute the NLO QCD corrections for the inclusive nonleptonic decay rates of $B$-hadrons at subleading power of the heavy quark expansion. In particular, we discuss the coefficient of the chromomagnetic moment parameter…

High Energy Physics - Phenomenology · Physics 2024-08-14 Thomas Mannel , Daniel Moreno , Alexei A. Pivovarov

The radiative corrections to the pure leptonic decay $B_c \to \ell\nu_{\ell}$ up-to one-loop order is presented. How to cancel the infrared divergences appearing in the loop calculations, and the radiative decay $B_c \to…

High Energy Physics - Phenomenology · Physics 2011-03-23 Chao-hsi Chang , Cai-Dian Lu , Guo-Li Wang , Hong-Shi Zong