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Related papers: Three-loop matching of heavy flavor-changing (axia…

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We present the next-to-next-to-leading order (NNLO) QCD corrections to the decay constants for both the pseudoscalar and vector beauty-charmed mesons $B_{c}$ and $B^*_{c}$ in nonrelativistic QCD effective theory. Explicit NNLO calculation…

High Energy Physics - Phenomenology · Physics 2023-01-11 Wei Tao , Ruilin Zhu , Zhen-Jun Xiao

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

We present the three-loop QCD+QED mixed corrections to the on-shell quark mass and wave-function renormalization constants through orders $\mathcal{O}(\alpha_s^m\alpha^n)$ with $m+n=3$. We further derive the three-loop relation between the…

High Energy Physics - Phenomenology · Physics 2026-02-24 Long Chen , Hong-Yang Han , Zhe Li , Marco Niggetiedt

The non-diagonal correlators of vector and scalar currents are considered at three-loop order in QCD. The full mass dependence is computed in the case where one of the quarks is massless and the other one carries the mass $M$. As…

High Energy Physics - Phenomenology · Physics 2009-10-31 K. G. Chetyrkin , M. Steinhauser

The renormalization constant $Z_J$ of the flavor-singlet axial-vector current with a non-anticommuting $\gamma_5$ in dimensional regularization is determined to order $\alpha_s^3$ in QCD with massless quarks. In addition, the equality…

High Energy Physics - Phenomenology · Physics 2021-09-28 Long Chen

Non-relativistic QCD is applied for a lattice computation of the heavy-light meson decay constant in quenched approximation at $\beta=6.0$. Clear signals are obtained for the ground state at large times in the correlators, allowing a…

High Energy Physics - Lattice · Physics 2009-10-22 Shoji Hashimoto

The perturbative three-loop result for the thermodynamic potential of QCD at finite temperature and chemical potential as obtained in the framework of dimensional reduction is compared with the exact result in the limit of large flavor…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. Ipp , A. Rebhan , A. Vuorinen

The two-loop QCD radiative corrections to the $B_c$ meson leptonic decay rate are calculated in the framework of NRQCD factorization formalism. Two types of master integrals appearing in the calculation are obtained analytically for the…

High Energy Physics - Phenomenology · Physics 2015-07-29 Long-Bin Chen , Cong-Feng Qiao

We calculate the two-loop QCD mixing of the dimension-five flavor-changing operators that arise in the Standard Model after integrating out the $W$, $Z$ and Higgs bosons and the top-quark, i.e.~the mixing among gluonic and photonic magnetic…

High Energy Physics - Phenomenology · Physics 2011-07-19 M. Misiak , M. Muenz

The anomalous dimensions of the general flavour non-singlet quark bilinear currents \psi \gamma^{[\mu_1} ... \gamma^{\mu_n]} \psi are computed at three loops in quantum chromodynamics in the minimal subtraction scheme. The dimension of the…

High Energy Physics - Phenomenology · Physics 2009-10-31 J. A. Gracey

The decay B_s -> mu^+ mu^- in the Standard Model is generated by the well-known W-box and Z-penguin diagrams that give rise to an effective quark-lepton operator Q_A at low energies. We compute QCD corrections of order alpha_s^2 to its…

High Energy Physics - Phenomenology · Physics 2014-03-18 Thomas Hermann , Mikolaj Misiak , Matthias Steinhauser

The 3-loop heavy flavor corrections to deep-inelastic scattering are essential for consistent next-to-next-to-leading order QCD analyses. We report on the present status of the calculation of these corrections at large virtualities $Q^2$.…

High Energy Physics - Phenomenology · Physics 2014-11-21 J. Blümlein , A. De Freitas , C. Schneider

Hadronic matrix elements involving tensor currents play an important r\^ole in decays that allow to probe the consistency of the Standard Model via precision lattice QCD calculations. The non-singlet tensor current is a scale-dependent…

High Energy Physics - Lattice · Physics 2023-09-11 L. Chimirri , P. Fritzsch , J. Heitger , F. Joswig , M. Panero , C. Pena , D. Preti

We provide the renormalization constants of the axial current operators, both singlet and non-singlet, in dimensional regularization up to four-loop order in QCD, determined using the off-shell Ward-Takahashi identity for an axial current…

High Energy Physics - Phenomenology · Physics 2022-02-04 Long Chen , Michał Czakon

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

We compute the two-loop QCD corrections to the heavy quark form factors in case of the vector, axial-vector, scalar and pseudo-scalar currents up to second order in the dimensional parameter $\epsilon = (4-D)/2$. These terms are required in…

High Energy Physics - Phenomenology · Physics 2018-05-30 J. Ablinger , A. Behring , J. Blümlein , G. Falcioni , A. De Freitas , P. Marquard , N. Rana , C. Schneider

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 consider the Lagrange density of non-relativistic Quantum Chromodynamics expanded up to order $1/m^2$, where $m$ is the heavy quark mass, and compute several matching coefficients up to two-loop order. Our results are building blocks for…

High Energy Physics - Phenomenology · Physics 2019-09-25 Marvin Gerlach , Go Mishima , Matthias Steinhauser

We investigate the effects of including the full three-loop QCD correction to the static short distance $1/r$ potential on the spectroscopy and decays in the charmonium and upsilon systems. We use a variational technique with the full…

High Energy Physics - Phenomenology · Physics 2013-08-28 Wayne W. Repko , Marco D. Santia , Stanley F. Radford

We present the results of a perturbative calculation to match the axial and vector currents for semileptonic $B\to D^{(\ast)}$ decays in lattice NRQCD to the continuum \MSb scheme. The matching is performed to $O(\alpha_s\frac{\vec{p}}{M})$…

High Energy Physics - Lattice · Physics 2014-11-17 P Boyle , C Davies