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Related papers: Three-Loop Chromomagnetic Interaction in HQET

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We present the analytical results for the anomalous chromomagnetic moment of a quark at the one-loop and two-loop levels through model-independent parameterizations, considering the external gluon to be off-shell. Then, we consider…

High Energy Physics - Phenomenology · Physics 2024-04-23 Subhadip Bisal

We review the current status of calculations of the HQET field anomalous dimension and the cusp anomalous dimension. In particular, we give the results at 4 loops for the quartic Casimir contribution, and for the full QED case, up to…

High Energy Physics - Phenomenology · Physics 2018-07-18 R. Brüser , A. G. Grozin , J. M. Henn , M. Stahlhofen

Measurements of electroweak precision observables at future electron-positron colliders, such as the CEPC, FCC-ee, and ILC, will be sensitive to physics at multi-TeV scales. To achieve this sensitivity, precise predictions for the Standard…

High Energy Physics - Phenomenology · Physics 2021-04-07 Lisong Chen , Ayres Freitas

We calculate the HQET quark-gluon vertex at one loop, for arbitrary external momenta, in an arbitrary covariant gauge and space-time dimension. Relevant results and algorithms for the three-point HQET integrals are presented. We also show…

High Energy Physics - Phenomenology · Physics 2009-01-07 A. I. Davydychev , A. G. Grozin

We calculate the small angle expansion of the four-loop QCD cusp anomalous dimension. As a byproduct of our calculation, we also obtain the four-loop anomalous dimension of the heavy-quark field in HQET. The validity of the calculational…

High Energy Physics - Phenomenology · Physics 2022-11-18 Andrey G. Grozin , Roman N. Lee , Andrey F. Pikelner

We show that the infinite imaginary anomalous dimensions of certain heavy quark-antiquark currents in the HQET arise due to an inappropriate commutation of two limits, namely coinciding velocities and infinite cut-off. This commutation is…

High Energy Physics - Phenomenology · Physics 2009-09-25 A. Pineda , J. Soto

Interactions of heavy quarks, in particular of top quarks, with electroweak gauge bosons are expected to be very sensitive to new physics effects related to electroweak symmetry breaking. These interactions are described by the so-called…

High Energy Physics - Phenomenology · Physics 2016-09-06 W. Bernreuther , R. Bonciani , T. Gehrmann , R. Heinesch , T. Leineweber , P. Mastrolia , E. Remiddi

We describe several techniques for the calculation of multi-loop integrals and their application to heavy quark current correlators. As new results, we present the four-loop correction to the second and third physical moment in the…

High Energy Physics - Phenomenology · Physics 2009-10-06 A. Maier , P. Maierhoefer , P. Marquard , A. V. Smirnov

We compute the two-loop mixed QCD-Electroweak corrections to $q \overline{q} \to H g$ and its crossed channels $q g \to H q$, $\overline{q} g \to H \overline{q}$, limiting ourselves to the contribution of light virtual quarks. We compute…

High Energy Physics - Phenomenology · Physics 2022-07-18 Marco Bonetti , Erik Panzer , Lorenzo Tancredi

We compute the eighth-order fermionic corrections involving two and three closed massless fermion loops to the anomalous magnetic moment of the muon. The required four-loop on-shell integrals are classified and explicit analytical results…

High Energy Physics - Phenomenology · Physics 2015-06-12 Roman Lee , Peter Marquard , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

After a brief introduction to Heavy Quark Effective Theory, we discuss $\alpha$ representation in HQET and methods of calculation of some kinds of HQET diagrams up to three loops.

High Energy Physics - Phenomenology · Physics 2008-12-12 A. G. Grozin

The calculation of the two-loop corrections to the electroweak gauge boson quartic couplings, growing quadratically with the Higgs boson mass, is reviewed. The potential of the CERN Large Hadron Collider and e+e- linear collider to study…

High Energy Physics - Phenomenology · Physics 2007-05-23 G. Jikia

We do a perturbative calculation of the anomalous chromomagnetic dipole moment of quarks at one-loop, also considering the effect of a small gauge-invariant mass of the gluon. We find partial agreement with a previous calculation, as well…

High Energy Physics - Phenomenology · Physics 2015-07-16 Ishita Dutta Choudhury , Amitabha Lahiri

The analytic calculation of the three-loop QCD $\beta$-function and anomalous dimensions within the minimal subtraction scheme in an arbitrary covariant guage is presented. The result for the $\beta$-function coincides with the previous…

High Energy Physics - Phenomenology · Physics 2011-05-05 S. A. Larin , J. A. M. Vermaseren

We evaluate the corrections to the matching coefficient of the vector current between Quantum Chromodynamics (QCD) and Non-Relativistic QCD (NRQCD) to three-loop order containing a closed heavy-fermion loop. The result constitutes a…

High Energy Physics - Phenomenology · Physics 2009-07-24 P. Marquard , J. H. Piclum , D. Seidel , M. Steinhauser

The numerically dominant QED contributions to the anomalous magnetic moment of the muon stem from Feynman diagrams with internal electron loops. We consider such corrections and present a calculation of the four-loop light-by-light-type…

High Energy Physics - Phenomenology · Physics 2015-11-04 Alexander Kurz , Tao Liu , Peter Marquard , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We find that the anomalous dimension (in the $\bar{MS}$ scheme) of the chromo-magnetic operator $g_s\bar h_v\sigma_{\mu\nu} G^{\mu\nu} h_v$ in the heavy-quark effective theory is \gamma_{mag} = (C_A\alpha_s / 2\pi) [1 + ( 17/18 C_A - 13/18…

High Energy Physics - Phenomenology · Physics 2009-10-30 G. Amorós , M. Beneke , M. Neubert

Within the framework of non-relativistic QCD (NRQCD) factorization, we compute the matching coefficients between full Quantum Chromodynamics (QCD) and NRQCD for the heavy flavor-changing vector, axial-vector, scalar and pseudo-scalar…

High Energy Physics - Phenomenology · Physics 2023-06-14 Wei Tao , Zhen-Jun Xiao , Ruilin Zhu

We compute the four-loop QCD corrections to the massless quark-anti-quark-photon form factor $F_q$ in the large-$N_c$ limit. From the pole part we extract analytic expressions for the corresponding cusp and collinear anomalous dimensions.

High Energy Physics - Phenomenology · Physics 2017-04-26 Johannes Henn , Roman N. Lee , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We present results on the two-loop anomalous dimensions of the heavy baryon HQET currents $J=(q^TC\Gamma\tau q)\Gamma'Q$ with arbitrary Dirac matrices $\Gamma$ and $\Gamma'$. From our general result we obtain the two-loop anomalous…

High Energy Physics - Phenomenology · Physics 2009-10-28 S. Groote , J. G. Körner , O. I. Yakovlev