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Related papers: Perturbative HQET

200 papers

Decoupling of c-quark loops in b-quark HQET is considered. The decoupling coefficients for the HQET heavy-quark field and the heavy-light quark current are calculated with the three-loop accuracy. The last result can be used to improve the…

High Energy Physics - Phenomenology · Physics 2009-11-11 A. G. Grozin , A. V. Smirnov , V. A. Smirnov

We use dimensional recurrence relations and analyticity to calculate four-loop propagator-type master integrals in the heavy-quark effective theory. Compared to previous applications of the DRA method, we apply a new technique of fixing…

High Energy Physics - Phenomenology · Physics 2023-03-01 Roman N. Lee , Andrey F. Pikelner

The lectures are a practical introduction to perturbative calculations in QED and QCD. I discuss methods of calculation of one- and two-loop diagrams in dimensional regularization, MSbar and on-shell renormalization schemes, decoupling of…

High Energy Physics - Phenomenology · Physics 2007-05-23 Andrey Grozin

We use Heavy Quark Effective Theory (HQET) techniques to parametrize certain non-perturbative effects related to quantum fluctuations that put both heavy quark and antiquark in quarkonium almost on shell. The large off-shell momentum…

High Energy Physics - Phenomenology · Physics 2016-09-01 A. Pineda , J. Soto

Effective field theories such as Heavy Quark Effective Theory (HQET) and Non Relativistic Quantum Chromo-(Electro-) dynamics NRQCD (NRQED) are indispensable tools in controlling the effects of the strong interaction. The increasing…

High Energy Physics - Phenomenology · Physics 2017-08-25 Ayesh Gunawardana , Gil Paz

I discuss methods of calculation of propagator diagrams (massless, those of Heavy Quark Effective Theory, and massive on-shell diagrams) up to 3 loops. Integration-by-parts recurrence relations are used to reduce them to linear combinations…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. G. Grozin

We present the coefficient of the chromomagnetic interaction operator, the only unknown coefficient in the Heavy Quark Effective Theory (HQET) lagrangian up to the $1/m$ level, with the two-loop accuracy by matching scattering amplitudes of…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Czarnecki , A. G. Grozin

This is a continuation of the lectures [1,2]. In this part we discuss interaction of electrons with soft photons in QED and Heavy Quark Effective Theory (HQET).

High Energy Physics - Phenomenology · Physics 2013-05-21 A. G. Grozin

The operator mixing matrix for the dimension six operators in the heavy quark effective theory Lagrangian is computed at one loop. The results are shown to be consistent with constraints from the equations of motion, and from…

High Energy Physics - Phenomenology · Physics 2009-10-30 Christian Bauer , Aneesh V. Manohar

We discuss the necessity of non-perturbative renormalization in QCD and HQET and explain the general strategy for solving this problem. A few selected topics are discussed in some detail, namely the importance of off-shell improvement in…

High Energy Physics - Lattice · Physics 2011-01-27 Rainer Sommer

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…

High Energy Physics - Phenomenology · Physics 2009-10-31 S. Groote , J. G. Körner , A. A. Pivovarov

We apply heavy-quark effective theory (HQET) to separate long- and short-distance effects of heavy quarks in lattice gauge theory. In this paper we focus on flavor-changing currents that mediate transitions from one heavy flavor to another.…

High Energy Physics - Lattice · Physics 2009-11-07 Junpei Harada , Shoji Hashimoto , Andreas S. Kronfeld , Tetsuya Onogi

We develop a new theoretical framework for the treatment of heavy quark (HQ) resonances within heavy quark effective theory (HQET). This framework uses on-shell recursion techniques to express the resonant amplitude as a product of on-shell…

High Energy Physics - Phenomenology · Physics 2025-03-03 Claudio Andrea Manzari , Dean J. Robinson

The perturbative contribution to the correlator of two heavy-light quark currents in HQET expanded in light-quark masses up to quadratic terms is calculated at the leading order in $1/\beta_0$. Ultraviolet and infrared renormalon poles of…

High Energy Physics - Phenomenology · Physics 2026-04-13 Andrey G. Grozin

We proposed a new formulation for heavy quark effective theory (HQET), whose Lagrangian is hermitian and has a manifest reparameterization invariance. As an application, we calculated the semileptonic and nonleptonic inclusive heavy hadron…

High Energy Physics - Phenomenology · Physics 2007-05-23 Tsung-Wen Yeh

Results of analytical calculations for heavy quark systems in higher orders of perturbation theory are overviewed. I discuss baryons with one finite mass quark in the next-to-leading order and heavy quark pair production near the threshold…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. A. Pivovarov

The application of the tensor formalism of the heavy quark effective theory (HQET) at leading order to strong decays of heavy hadrons is presented. Comparisons between experimental and theoretical predictions of ratios of decay rates for B…

High Energy Physics - Phenomenology · Physics 2014-11-17 N. Tregoures , W. Roberts

It was found that renormalization group equations in the heavy-quark effective theory (HQET) for the operators involving one effective heavy quark and light degrees of freedom are completely integrable in some cases and are related to spin…

High Energy Physics - Theory · Physics 2018-07-04 Vladimir M. Braun , Yao Ji , Alexander N. Manashov

A short review of a few selected topics in Heavy Quark Effective Theory is given. Applications to exclusive decays are discussed.

High Energy Physics - Phenomenology · Physics 2007-05-23 Thomas Mannel

The state of the art of the theoretical calculations for heavy quarks photoproduction is reviewed. The full next-to-leading order calculation and two possible resummations, the high energy one for total cross sections and the large $p_T$…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Cacciari