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Related papers: Perturbative HQET

200 papers

The existing derivations of a heavy quark effective theory (HQET) are analyzed beyond the next-to-leading order in $1/m$. With one exception they are found to be incorrect. The problem is a wrong normalization of the heavy quark field in…

High Energy Physics - Phenomenology · Physics 2009-10-22 S. Balk , J. G. Korner , D. Pirjol

We report on recent progress on five-loop calculations in perturbative QCD. We discuss the computation of the perturbative quark condensate, decoupling in QCD, and the precision determination of charm and bottom quark masses. For the…

High Energy Physics - Phenomenology · Physics 2024-07-24 Andreas Maier , Peter Marquard , York Schröder

We present a calculation of the renormalized HQET Lagrangian at order O(1/m_Q^3) in the one particle sector. The anomalous dimensions of local operators and time ordered products of dimension 7 contributing at this order are calculated in…

High Energy Physics - Phenomenology · Physics 2016-08-25 Christopher Balzereit

Applications of HQET and NRQCD to fragmentation are briefly reviewed. The special role of the b-quark in applications of heavy quark symmetry is discussed. Predictions of HQET for semileptonic B decays to excited charmed mesons are…

High Energy Physics - Phenomenology · Physics 2009-10-30 Mark B. Wise

A summary of the calculation of the color-planar and complete light quark contributions to the massive three-loop form factors is presented. Here a novel calculation method for the Feynman integrals is used, solving general uni-variate…

High Energy Physics - Phenomenology · Physics 2019-06-14 J. Ablinger , J. Blümlein , P. Marquard , N. Rana , C. Schneider

We comment on the calculation of the finite part of the heavy quark impact factor at next-to-leading logarithmic (NLx) accuracy. The result is presented in a form suitable for phenomenological studies such as the calculation of the…

High Energy Physics - Phenomenology · Physics 2013-10-30 Grigorios Chachamis , Michal Deak , German Rodrigo

We use simulations of heavy quark effective field theory to calculate the Isgur-Wise function, and we demonstrate the feasibility of calculating the matrix element for the $B \to \pi + \leptons$ decay in the lattice heavy quark effective…

High Energy Physics - Lattice · Physics 2008-11-26 C. Bernard , C. DeTar , Steven Gottlieb , U. M. Heller , J. Hetrick , B. Jegerlehner , C. McNeile , K. Rummukainen , R. Sugar , D. Toussaint , M. Wingate

During the last years, the ALPHA collaboration has been developing and implementing a method based on Heavy Quark Effective Theory (HQET) to compute B-mesons observables through lattice simulations. Thanks to a non-perturbative matching to…

High Energy Physics - Lattice · Physics 2015-03-18 Nicolas Garron

We determine the master integrals for vertex and propagator diagrams that appear in effective field theories containing heavy fields. The integrals involve at least one heavy line, and the standard lines include an arbitrary mass scale. The…

High Energy Physics - Phenomenology · Physics 2022-01-19 B. Assi , B. A. Kniehl , A. I. Onishchenko

A pole model for the form factors describing heavy to light meson transitions is constructed, and the results compared with the predictions of the heavy quark effective theory (HQET). While most of the HQET-predicted relationships among…

High Energy Physics - Phenomenology · Physics 2007-05-23 Winston Roberts

For the exploration of the phase diagram of QCD, effective Polyakov loop theories derived from lattice QCD provide a valuable tool in the heavy quark mass regime. Using mean field approximations these theories are evaluated in the high and…

High Energy Physics - Lattice · Physics 2025-02-03 Christoph Konrad , Owe Philipsen

We present a formulation of quantum circuit diagrams based on the exponential map which provides a new way to calculate graphically with circuits. We present a sound list of rewrite rules for this formulation and demonstrate a variety of…

Quantum Physics · Physics 2024-10-07 William Schober

We apply Heavy Quark Effective Theory to the production of $0^-$ and $1^-$ $Q\bar{q}$ states in $e^+ e^-$ annihilation. We show that HQET implies that the electric quadrupole amplitudes vanish and we propose tests for this theory. We also…

High Energy Physics - Phenomenology · Physics 2009-10-22 F. E. Close , G. J. Gounaris

I calculate heavy-light decay constants in a nonrelativistic potential model. The resulting estimate of heavy quark symmetry breaking conflicts with similar estimates from lattice QCD. I show that a semirelativistic potential model…

High Energy Physics - Phenomenology · Physics 2011-07-19 James F. Amundson

We set up a method for a recursive calculation of the effective potential which is applied to a cubic potential with imaginary coupling. The result is resummed using variational perturbation theory (VPT), yielding an exponentially fast…

Quantum Physics · Physics 2009-12-06 Sebastian F. Brandt , Hagen Kleinert , Axel Pelster

We compute semi-leptonic $B_s$ decay form factors using Heavy Quark Effective Theory on the lattice. To obtain good control of the $1/m_b$ expansion, one has to take into account not only the leading static order but also the terms arising…

High Energy Physics - Lattice · Physics 2018-04-18 Debasish Banerjee , Mateusz Koren , Hubert Simma , Rainer Sommer

A perturbative approach to quantum field theory involves the computation of loop integrals, as soon as one goes beyond the leading term in the perturbative expansion. First I review standard techniques for the computation of loop integrals.…

High Energy Physics - Phenomenology · Physics 2007-05-23 Stefan Weinzierl

We evaluate the second and fourth order quark number susceptibilities in hot QCD using two variations of resummed perturbation theory. On one hand, we carry out a one-loop calculation within hard-thermal-loop perturbation theory, and on the…

High Energy Physics - Phenomenology · Physics 2013-04-10 Jens O. Andersen , Sylvain Mogliacci , Nan Su , Aleksi Vuorinen

In this talk I briefly review the recent progress in calculation of the high order corrections to the parameters of the nonrelativistic heavy quark-antiquark system in the effective theory approach.

High Energy Physics - Phenomenology · Physics 2009-10-31 A. A. Penin

The gauge invariant method for calculation of the effective action of the local composite fields in QFT is proposed. The effective action of the local composite fields in QED is studied up to 2-loop level. The graph rules for the local…

High Energy Physics - Theory · Physics 2007-05-23 S. A. Garnov