scholarly journals On perturbative aspects of a nonminimal Lorentz-violating QED with CPT-odd dimension-5 terms

2021 ◽  
Vol 81 (11) ◽  
Author(s):  
T. Mariz ◽  
R. Martinez ◽  
J. R. Nascimento ◽  
A. Yu. Petrov
Keyword(s):  
Dimensional Regularization ◽  
Regularization Scheme ◽  
First Order ◽  
Higher Derivative

AbstractWe consider the Lorentz-violating extended QED involving all nonminimal dimension-5 additive CPT-odd terms. For this theory, we investigate the generation of the Carroll–Field–Jackiw (CFJ) term and its higher-derivative counterparts of the first order in any of these nonminimal couplings. The CFJ term is demonstrated to vanish in the dimensional regularization scheme. We also study the question of higher-derivative divergent contributions and demonstrate that they can be eliminated by considering a given proportionality between the coefficients.

scholarly journals A prescription for projectors to compute helicity amplitudes in D dimensions

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
Long Chen
Keyword(s):  
Dimensional Regularization ◽  
Tensor Decomposition ◽  
Regularization Scheme ◽  
Lorentz Index ◽  
Dimensional Splitting ◽  
Lorentz Tensor ◽  
Helicity Amplitudes ◽  
Amplitude Level ◽  
Infrared Singularities

AbstractThis article discusses a prescription to compute polarized dimensionally regularized amplitudes, providing a recipe for constructing simple and general polarized amplitude projectors in D dimensions that avoids conventional Lorentz tensor decomposition and avoids also dimensional splitting. Because of the latter, commutation between Lorentz index contraction and loop integration is preserved within this prescription, which entails certain technical advantages. The usage of these D-dimensional polarized amplitude projectors results in helicity amplitudes that can be expressed solely in terms of external momenta, but different from those defined in the existing dimensional regularization schemes. Furthermore, we argue that despite being different from the conventional dimensional regularization scheme (CDR), owing to the amplitude-level factorization of ultraviolet and infrared singularities, our prescription can be used, within an infrared subtraction framework, in a hybrid way without re-calculating the (process-independent) integrated subtraction coefficients, many of which are available in CDR. This hybrid CDR-compatible prescription is shown to be unitary. We include two examples to demonstrate this explicitly and also to illustrate its usage in practice.

scholarly journals Modern Technique for Real Photon Radiative Correction Calculations

2021 ◽  
Vol 24 (2) ◽  
pp. 184-191
Author(s):  
I. A. Shershan ◽  
T. V. Shishkina
Keyword(s):  
Gauge Boson ◽  
Cross Sections ◽  
Dimensional Regularization ◽  
Real Photon ◽  
Boson Production ◽  
Radiative Corrections ◽  
Hard Photon ◽  
Regularization Scheme ◽  
Modern Technique ◽  
Bremsstrahlung Contribution

The problem of the bremsstrahlung contribution calculation as a part of the radiative corrections in the case of single gauge boson production was discussed. It was shown that the hard photon bremsstrahlung contribution can be divided into the finite and divergent terms. The exact calculation of soft photon bremsstrahlung and infrared part of hard photon bremsstrahlung was presented in frame of the dimensional regularization scheme. Numerical analysis of radiative corrections to the cross sections of single gauge boson production was performed.

scholarly journals REGULARIZATION PARAMETER INDEPENDENT ANALYSIS IN NAMBU–JONA-LASINIO MODEL

2013 ◽  
Vol 28 (31) ◽  
pp. 1350164 ◽  
Author(s):  
T. INAGAKI ◽  
D. KIMURA ◽  
H. KOHYAMA ◽  
A. KVINIKHIDZE
Keyword(s):  
Regularization Parameter ◽  
Dimensional Regularization ◽  
Low Energy ◽  
Leading Order ◽  
Regularization Scheme ◽  
Independent Analysis

Nambu–Jona-Lasinio model used to investigate low energy phenomena is nonrenormalizable, therefore the results depend on the regularization parameter in general. A possibility of the finite in four-dimensional limit and even the in regularization parameter (this is dimension in the dimensional regularization scheme) independent analysis is shown in the leading order of the 1/Nc expansion.

scholarly journals Discussing quantum aspects of higher-derivative 3-D gravity in the first-order formalism

2010 ◽  
Vol 67 (1-2) ◽  
pp. 311-319 ◽  
Author(s):  
J. A. Helayël-Neto ◽  
L. M. de Moraes ◽  
V. J. Vasquez
Keyword(s):  
First Order ◽  
Higher Derivative ◽  
Quantum Aspects

scholarly journals GEOMETRICALLY RELATING MOMENTUM CUT-OFF AND DIMENSIONAL REGULARIZATION

2012 ◽  
Vol 10 (02) ◽  
pp. 1250081 ◽  
Author(s):  
SUSAMA AGARWALA
Keyword(s):  
Field Theory ◽  
Scalar Field ◽  
Hopf Algebras ◽  
Dimensional Regularization ◽  
Mass Scale ◽  
Feynman Diagrams ◽  
Field Theories ◽  
Coupling Constant ◽  
Regularization Scheme ◽  
Β Function

The β function for a scalar field theory describes the dependence of the coupling constant on the renormalization mass scale. This dependence is affected by the choice of regularization scheme. I explicitly relate the β functions of momentum cut-off regularization and dimensional regularization on scalar field theories by a gauge transformation using the Hopf algebras of the Feynman diagrams of the theories.

Feynman integrals and hypergeometric functions

2014 ◽  
Vol 05 (supp01) ◽  
pp. 1441001
Author(s):  
Héctor Luna García ◽  
Luz María García
Keyword(s):  
Hypergeometric Functions ◽  
Dimensional Regularization ◽  
Feynman Integrals ◽  
Regularization Scheme

We review Davydychev method for calculating Feynman integrals for massive and no massive propagators, by employing Mellin–Barnes transformation and the dimensional regularization scheme, same that lead to hypergeometric functions. In particular, an example is calculated explicitly from such a method.

A canonical Hamiltonian analysis of Podolsky’s generalized electrodynamics in first-order formalism

2021 ◽  
Vol 36 (10) ◽  
pp. 2150068
Author(s):  
Jialiang Dai
Keyword(s):  
Degrees Of Freedom ◽  
Gauge Condition ◽  
Quantization Scheme ◽  
Constrained System ◽  
First Order ◽  
Higher Derivative ◽  
Gauge Fixing ◽  
Derivative System ◽  
New Variables ◽  
Hamiltonian Analysis

We give a canonical Hamiltonian analysis of Podolsky’s generalized electrodynamics by introducing two sets of new variables which help us transform the Lagrangian into an equivalent first-order formalism. After eliminating the unphysical sector, we calculate the physical degrees of freedom of the higher derivative system and obtain the Dirac brackets in the reduced phase space. Then with the aid of the first-class constraints, we construct the independent gauge generator which is closely connected with the BRST charge and the BRST-invariant Hamiltonian. Finally, by choosing appropriate gauge-fixing fermion, we evaluate the path integral of this higher derivative constrained system in BRST quantization scheme with the generalized Lorenz gauge condition.

SUPERSYMMETRY AND THE FOUR-DIMENSIONAL COUNTERPART OF DIMENSIONAL REGULARIZATION

1992 ◽  
Vol 07 (01) ◽  
pp. 41-59
Author(s):  
J. NOVOTNÝ
Keyword(s):  
Gauge Invariance ◽  
Dimensional Reduction ◽  
Dimensional Regularization ◽  
Explicit Calculation ◽  
Regularization Scheme

A supersymmetric generalization of the natural four-dimensional counterpart of canonical dimensional regularization developed recently is discussed for SUSY QED. The gauge invariance of the regularization scheme is proved and the method illustrated by simple examples of explicit calculation of one-loop supergraphs. The relation to the regularization by dimensional reduction is briefly discussed.

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