Related papers: Higher radiative corrections in HQET
Methods of calculation of loop diagrams in Heavy Quark Effective Theory (HQET) are presented.
We review algorithmic methods for two-loop calculations in HQET, and the analogous methods for on-shell QCD, needed for matching HQET to QCD.
Three-loop propagator diagrams in HQET can be reduced, using integration by parts, to 8 basis integrals: 5 trivial ones, two expressible via 3F2, and one only known up to \epsilon^0. Calculation of the heavy-quark propagator in HQET is…
Effective field theories such as Heavy Quark Effective Theory (HQET) are indispensable tools in controlling the effects of the strong interaction. The increasing experimental precision requires the knowledge of higher dimensional operators.…
The perturbative contribution to the correlator of two HQET heavy-light currents expanded in light-quark masses up to quadratic terms is calculated up to 4 loops. The leading large-$\beta_0$ limit is also considered, so that terms with the…
Heavy Quark Effective Theory (HQET) is a new approach to QCD problems involving a heavy quark. In the leading approximation, the heavy quark is considered as a static source of the gluon field; 1/m corrections can be systematically included…
We show that the different ways of deriving the Heavy Quark Effective Theory (HQET) lead to equivalent theories. The equivalence can be established through a careful redefinition of the field variables. We demonstrate the equivalence to…
We present a calculation of the renormalized heavy-light and heavy-heavy currents in HQET at order O(1/m_Q^2).
We give an introduction to Heavy Quark Effective Theory (HQET). Our emphasis is on its formulation non-perturbative in the strong coupling, including the non-perturbative determination of the parameters in the HQET Lagrangian. In a second…
An algorithm for calculation of three-loop propagator diagrams in HQET, based on integration-by-parts recurrence relations, is constructed and implemented as a REDUCE package Grinder, and in Axiom.
Recently, algorithms for calculation of 3-loop propagator diagrams in HQET and on-shell QCD with a heavy quark have been constructed and implemented. These algorithms (based on integration by parts recurrence relations) reduce an arbitrary…
In the context of the observed decay $B \rightarrow K^* \gamma$ the applicability of the Heavy Quark Effective Theory (HQET), treating both b and s as heavy quarks, is examined. We show that the heavy s-quark approximation, as can be found…
The Heavy quark effective field theory (HQEFT) is revisited in a more intuitive way. It is shown that HQEFT is a consistent large component QCD of heavy quarks. In the non-relativistic limit, HQEFT recovers the non-relativistic QCD (NRQCD).…
The anomalous dimension of the heavy-light quark current in HQET is calculated up to four loops. The N$^3$LL perturbative correction to $f_B/f_D$ is obtained.
In this talk we review recent perturbative and non-perturbative developments in Heavy Quark Effective Theory (HQET).
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).
Higher order calculations in perturbative Quantum Field Theories often produce coupled linear systems of differential equations which factorize to first order. Here we present an algorithm to solve such systems in terms of iterated…
We consider the currents formed by a heavy and a light quark within Quantum Chromodynamics and compute the matching to Heavy Quark Effective Theory to three-loop accuracy. As an application we obtain the third-order perturbative corrections…
QCD/HQET matching for the heavy-quark field and heavy-light quark currents with three-loop accuracy is discussed.
Coefficient functions of the operator product expansion of correlators of HQET heavy--light quark currents are calculated up operators of dimension 4 up to to 3 loops.