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相关论文: Matching QCD and HQET heavy--light currents at two…

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We compute three-loop corrections of $\mathcal{O}(\alpha_{s}^3)$ to form factors with one massive and one massless quark coupling to an external vector, axialvector, scalar, pseudoscalar, or tensor current. We obtain analytic results for…

高能物理 - 唯象学 · 物理学 2024-09-24 Matteo Fael , Tobias Huber , Fabian Lange , Jakob Müller , Kay Schönwald , Matthias Steinhauser

We present a calculation of the renormalized heavy-light and heavy-heavy currents in HQET at order O(1/m_Q^2).

高能物理 - 唯象学 · 物理学 2009-10-30 Christopher Balzereit , Thorsten Ohl

We calculate the full set of the two-loop master integrals for heavy-to-light form factors of two different massive fermions for arbitrary momentum transfer in NNLO QCD or QED corrections. These integrals allow to determine the two-loop QCD…

高能物理 - 唯象学 · 物理学 2018-04-04 Long-Bin Chen

We use conformal symmetry to calculate the NNLO anomalous dimension matrix (three loops) for flavor-singlet axial-vector QCD operators for spin $N \le 8$ from a set of gauge-invariant two-point correlation functions. Combining this result…

高能物理 - 唯象学 · 物理学 2025-10-20 V. M. Braun , K. G. Chetyrkin , A. N. Manashov

We compute the two-loop QCD corrections to $q g \to H q$ and $q \bar{q} \to H g$ amplitudes mediated by loops of nearly massless quarks. These amplitudes provide the last missing ingredient required to compute the NLO QCD corrections to the…

高能物理 - 唯象学 · 物理学 2017-03-22 Kirill Melnikov , Lorenzo Tancredi , Christopher Wever

We evaluate the three-loop corrections to the matching coefficient of the vector current between Quantum Chromodynamics (QCD) and non-relativistic QCD. The result is presented in the MSbar scheme where large perturbative corrections are…

高能物理 - 唯象学 · 物理学 2014-03-05 Peter Marquard , Jan H. Piclum , Dirk Seidel , Matthias Steinhauser

In this contribution the QCD next-to-next-to-leading order (NNLO) matching coefficients to the branching ratio $B_s \to \mu^+ \mu^-$ in the Standard Model (SM) and to $\bar{B}\to X_s \gamma$ in the Two Higgs Doublet Model (2HDM) are…

高能物理 - 唯象学 · 物理学 2013-11-22 Thomas Hermann

This talk presents details of the calculation of two-loop corrections to heavy baryon currents containing one heavy quark in leading order of the $1/m_Q$-expansion, i.e. in the limit of Heavy Quark Symmetry (HQS). The calculations lead to…

高能物理 - 唯象学 · 物理学 2007-05-23 Stefan Groote

We match the continuum and lattice axial vector and vector currents at one loop in perturbation theory. For the heavy quarks we use the nonrelativistic QCD (NRQCD) action and for the light quarks the Highly Improved Staggered Quark (HISQ)…

高能物理 - 格点 · 物理学 2013-04-18 Christopher Monahan , Junko Shigemitsu , Ron Horgan

The recent experimental observation of Light-by-Light (LbL) scattering at the Large Hadron Collider has revived interest in this fundamental process, and especially of the accurate prediction of its cross-section, which we present here for…

高能物理 - 唯象学 · 物理学 2024-03-12 Ajjath A H , Ekta Chaubey , Mathijs Fraaije , Valentin Hirschi , Hua-Sheng Shao

We present analytical next-to-leading order results for the correlator of baryonic currents at the three-loop level with one finite mass quark. We obtain the massless and the HQET limits of the correlator as particular cases from the…

高能物理 - 唯象学 · 物理学 2009-10-31 S. Groote , J. G. Körner , A. A. Pivovarov

We compute the four-loop corrections to the Higgs-bottom vertex within massless QCD and present analytic results for all color structures. The infrared poles of the renormalized form factor agree with the predicted four-loop pattern.…

We compute the exact two-loop matching coefficients for the strong coupling constant alpha_s and the bottom-quark mass m_b within the Minimal Supersymmetric Standard Model (MSSM), taking into account O(alpha_s^2) contributions from…

高能物理 - 唯象学 · 物理学 2010-04-15 A. Bauer , L. Mihaila , J. Salomon

We compute the fermionic contributions to the cusp anomalous dimension in QCD at four loops as an expansion for small cusp angle. As a byproduct we also obtain the respective terms of the four-loop HQET wave function anomalous dimension.…

高能物理 - 唯象学 · 物理学 2019-06-26 Robin Brüser , Andrey Grozin , Johannes M. Henn , Maximilian Stahlhofen

We extend our earlier lattice-QCD analysis of heavy-quark correlators to smaller lattice spacings and larger masses to obtain new values for the c mass and QCD coupling, and, for the first time, values for the b mass:…

高能物理 - 格点 · 物理学 2014-11-20 C. McNeile , C. T. H. Davies , E. Follana , K. Hornbostel , G. P. Lepage

Calculation results for the HQET field anomalous dimension and the QCD cusp anomalous dimension, as well as their properties, are reviewed. The HQET field anomalous dimension $\gamma_h$ is known up to 4 loops. The cusp anomalous dimension…

高能物理 - 唯象学 · 物理学 2024-02-27 Andrey Grozin

We numerically compute the two-loop QCD corrections to $Z\gamma$ production at the LHC mediated by light- and heavy-quark box loops. The calculation employs the pipeline of refs. arXiv:2407.18051 and arXiv:2510.18801, which performs Monte…

高能物理 - 唯象学 · 物理学 2026-03-04 Dario Kermanschah , Matilde Vicini

The most general QCD next-to-leading anomalous-dimension matrix of all possible four-fermion, dimension-six $\Delta F=2$ operators is computed. The results of this calculation can be used in many phenomenological applications, among which…

高能物理 - 唯象学 · 物理学 2009-10-30 M. Ciuchini , E. Franco , V. Lubicz , G. Martinelli , I. Scimemi , L. Silvestrini

I present one-loop perturbative calculations of matching coefficients between matrix elements in continuum regulated QCD and lattice QCD with overlap fermions, with emphasis a recently-proposed variant discretization of the overlap. These…

高能物理 - 格点 · 物理学 2016-09-01 Thomas DeGrand

The resummation of soft gluon exchange for QCD hard scattering requires a matrix of anomalous dimensions, which has been computed through two loops. The two-loop matrix is proportional to the one-loop matrix. Recently there have been…

高能物理 - 唯象学 · 物理学 2009-10-29 Lance J. Dixon