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We discuss a lattice QCD computation of the $B$-meson decay constants by the ETM collaboration where suitable ratios allow to reach the bottom quark sector by combining simulations around the charm-quark mass with an exactly known static…

We present an analytical calculation of the two-loop QCD corrections to the electromagnetic form factor of heavy quarks. The two-loop contributions to the form factor are reduced to linear combinations of master integrals, which are…

High Energy Physics - Phenomenology · Physics 2009-07-29 J. Gluza , A. Mitov , S. Moch , T. Riemann

In this paper we compute the decay constant of the pseudo-scalar heavy-light mesons in the heavy quark effective theory framework of QCD sum rules. In our analysis we include the recently evaluated three-loop result of order $\alpha_s^2$…

High Energy Physics - Phenomenology · Physics 2011-01-27 A. A. Penin , M. Steinhauser

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 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 the Non-Relativistic QCD (NRQCD) calculations at the next-to-leading order (NLO) of $\alpha_s$ for $B_c^*\to \eta_c$ vector, axial-vector, tensor and axial-tensor form factors, and obtain complete analytical expressions for the…

High Energy Physics - Phenomenology · Physics 2026-03-18 Wei Tao , Ya-Hui Zhao , Li-Ting Wang , Qin Chang , Zhen-Jun Xiao

In the framework of nonrelativistic QCD (NRQCD) factorization, we compute both the polarized and the unpolarized decay widths for the processes $\eta_b(\chi_{bJ})\to J/\psi J/\psi$, accurate up to next-to-next-to-leading-order (NNLO) in…

High Energy Physics - Phenomenology · Physics 2023-10-13 Yu-Dong Zhang , Xiao-Wei Bai , Feng Feng , Wen-Long Sang , Ming-Zhen Zhou

We consider a general scheme for calculating the leptonic constant of heavy quarkonium QQ-bar in the framework of nonrelativistic quantum chromodynamics, NRQCD, operating as the effective theory of nonrelativistic heavy quarks. We explore…

High Energy Physics - Phenomenology · Physics 2009-11-07 V. V. Kiselev , A. K. Likhoded , O. N. Pakhomova , V. A. Saleev

We calculate the next-to-next-to-leading order QCD corrections to the leptonic invariant mass ($q^2$) spectrum of semileptonic $b \to c$ inclusive decays, taking into account the mass of the charm quark and the charged lepton in the final…

High Energy Physics - Phenomenology · Physics 2024-03-08 Matteo Fael , Florian Herren

We propose to resum exactly any number of one-loop vacuum polarization insertions into the scale of the coupling of lowest order radiative corrections. This makes maximal use of the information contained in one-loop perturbative corrections…

High Energy Physics - Phenomenology · Physics 2010-11-01 P. Ball , M. Beneke , V. M Braun

We present $O(\alpha_s^2)$ QCD corrections to the fully-differential decay rate of a $b$-quark into inclusive semileptonic charmless final states. Our calculation provides genuine two-loop QCD corrections, beyond the…

High Energy Physics - Phenomenology · Physics 2015-06-12 Mathias Brucherseifer , Fabrizio Caola , Kirill Melnikov

In this paper we consider the matching coefficient of the vector current between Quantum Chromodynamics (QCD) and Non-Relativistic QCD (NRQCD) to three-loop order in perturbation theory. We evaluate the fermionic corrections containing a…

High Energy Physics - Phenomenology · Physics 2008-11-26 P. Marquard , J. H. Piclum , D. Seidel , M. Steinhauser

We calculate the radiative corrections to the nonleptonic inclusive B decay mode $b\rightarrow c\bar u d$ taking into account the charm quark mass. Compared to the massless case, corrections resulting from a nonvanishing c quark mass…

High Energy Physics - Phenomenology · Physics 2011-01-25 E. Bagan , P. Ball , V. M. Braun , P. Gosdzinsky

We compute the QCD form factor resumming threshold logarithms in B --> X_c + l + nu_l decays to next-to-leading logarithmic approximation. We present an interpolation formula including soft as well as collinear effects softened by the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ugo Aglietti , Leonardo Di Giustino , Giancarlo Ferrera , Alessandro Renzaglia , Giulia Ricciardi , Luca Trentadue

The decay rates of $Q \bar Q$ mesons ($Q \varepsilon {c, b}$) are studied in the NRQCD formalism in terms of their short distance and long distance coefficients. The long distance coefficients are obtained through phenomenological potential…

High Energy Physics - Phenomenology · Physics 2008-12-18 Ajay Kumar Rai , Bhavin Patel , P C Vinodkumar

In this paper we consider the matching coefficients up to two loops between Quantum Chromodynamics (QCD) and Non-Relativistic QCD (NRQCD) for the vector, axial-vector, scalar and pseudo-scalar currents. The structure of the effective theory…

High Energy Physics - Phenomenology · Physics 2009-11-11 B. A. Kniehl , A. Onishchenko , J. H. Piclum , M. Steinhauser

In this paper, we calculate the next-to-leading order (NLO) quantum chromodynamics (QCD) corrections to the exclusive processes $B_c^+\to \chi_{cJ}(h_c)\pi^+$ in the framework of the nonrelativistic QCD (NRQCD) factorization formalism. The…

High Energy Physics - Phenomenology · Physics 2021-07-28 Zi-Qiang Chen , Cong-Feng Qiao

We study the radiative leptonic $B_c\to \gamma\ell\bar\nu$ decays in the nonrelativistic QCD effective field theory, and consider a fast-moving photon. As a result the interactions with the heavy quarks can be integrated out, and thus we…

High Energy Physics - Phenomenology · Physics 2015-10-14 Wei Wang , Rui-Lin Zhu

We calculate the next-to-leading order(NLO) quantum chromodynamics(QCD) corrections to the inclusive process of $Z_0 \rightarrow B^*_c+\bar{c}+b$ under the non-relativistic QCD(NRQCD) factorization scheme. Technical details about…

High Energy Physics - Phenomenology · Physics 2015-03-05 Jun Jiang , Long-Bin Chen , Cong-Feng Qiao

In this paper, we compute the relativistic corrections to the fragmentation functions (FFs) of a heavy quark to $B_c$ and $B_c^*$ within the framework of non-relativistic QCD (NRQCD) factorization. The non-singlet and singlet DGLAP…

High Energy Physics - Phenomenology · Physics 2019-09-04 Deshan Yang , Wenjie Zhang