scholarly journals Gauge dependence of tadpole and mass renormalization for a seesaw extended 2HDM

2018 ◽  
Vol 98 (3) ◽  
Author(s):  
Vytautas Dūdėnas ◽  
Thomas Gajdosik
Keyword(s):  
Mass Renormalization ◽  
Gauge Dependence

GAUGE DEPENDENCE OF FERMION MASS RENORMALIZATION PRESCRIPTIONS

2009 ◽  
Vol 24 (04) ◽  
pp. 291-304
Author(s):  
YONG ZHOU
Keyword(s):  
Fermion Mass ◽  
Pole Mass ◽  
Mass Renormalization ◽  
Gauge Dependence ◽  
Loop Level ◽  
The Difference ◽  
First Time ◽  
Level Calculation ◽  
Physical Result ◽  
Mass Definition

We discuss the gauge dependence of fermion mass definition under the on-shell and pole mass renormalization prescriptions. By the two-loop-level calculation of the cross section of the physical process [Formula: see text], we prove for the first time that the on-shell fermion mass renormalization prescription makes physical result gauge-dependent. On the other hand, such gauge dependence does not appear in the result of the pole mass renormalization prescription. Our calculation also implies that the difference of physical results between the two mass renormalization prescriptions cannot be neglected at two-loop level.

scholarly journals Gauge invariance, polar coordinates and inflation

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Ali Akil ◽  
Xi Tong
Keyword(s):  
Coordinate System ◽  
Effective Potential ◽  
Gauge Invariance ◽  
Polar Coordinates ◽  
Quantum Corrections ◽  
Background Current ◽  
Gauge Invariant ◽  
Gauge Dependence ◽  
Current Term ◽  
Invariant Current

Abstract We point out the necessity of resolving the apparent gauge dependence in the quantum corrections of cosmological observables for Higgs-like inflation models. We highlight the fact that this gauge dependence is due to the use of an asymmetric background current which is specific to a choice of coordinate system in the scalar manifold. Favoring simplicity over complexity, we further propose a practical shortcut to gauge-independent inflationary observables by using effective potential obtained from a polar-like background current choice. We demonstrate this shortcut for several explicit examples and present a gauge-independent prediction of inflationary observables in the Abelian Higgs model. Furthermore, with Nielsen’s gauge dependence identities, we show that for any theory to all orders, a gauge-invariant current term gives a gauge-independent effective potential and thus gauge-invariant inflationary observables.

scholarly journals A critical look at the electroweak phase transition

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Andreas Ekstedt ◽  
Johan Löfgren
Keyword(s):  
Phase Transition ◽  
Generic Model ◽  
Electroweak Symmetry ◽  
Electroweak Phase Transition ◽  
Gauge Dependence ◽  
Perturbative Methods ◽  
The Standard Model ◽  
Gauge Fixing ◽  
Infrared Divergences ◽  
General Gauge

Abstract The electroweak phase transition broke the electroweak symmetry. Perturbative methods used to calculate observables related to this phase transition suffer from severe problems such as gauge dependence, infrared divergences, and a breakdown of perturbation theory. In this paper we develop robust perturbative tools for dealing with phase transitions. We argue that gauge and infrared problems are absent in a consistent power-counting. We calculate the finite temperature effective potential to two loops for general gauge-fixing parameters in a generic model. We demonstrate gauge invariance, and perform numerical calculations for the Standard Model in Fermi gauge.

scholarly journals Finite BRST–anti-BRST transformations in generalized Hamiltonian formalism

2014 ◽  
Vol 29 (27) ◽  
pp. 1450159 ◽  
Author(s):  
Pavel Yu. Moshin ◽  
Alexander A. Reshetnyak
Keyword(s):  
Dynamical Systems ◽  
Path Integral ◽  
Hamiltonian Path ◽  
Hamiltonian Formalism ◽  
Lagrangian Formalism ◽  
Yang Mills ◽  
Gauge Dependence ◽  
Field Dependent ◽  
Gauge Fixing ◽  
Constrained Dynamical Systems

We introduce the notion of finite BRST–anti-BRST transformations for constrained dynamical systems in the generalized Hamiltonian formalism, both global and field-dependent, with a doublet λa, a = 1, 2, of anticommuting Grassmann parameters and find explicit Jacobians corresponding to these changes of variables in the path integral. It turns out that the finite transformations are quadratic in their parameters. Exactly as in the case of finite field-dependent BRST–anti-BRST transformations for the Yang–Mills vacuum functional in the Lagrangian formalism examined in our previous paper [arXiv:1405.0790 [hep-th]], special field-dependent BRST–anti-BRST transformations with functionally-dependent parameters λa= ∫ dt(saΛ), generated by a finite even-valued function Λ(t) and by the anticommuting generators saof BRST–anti-BRST transformations, amount to a precise change of the gauge-fixing function for arbitrary constrained dynamical systems. This proves the independence of the vacuum functional under such transformations. We derive a new form of the Ward identities, depending on the parameters λaand study the problem of gauge dependence. We present the form of transformation parameters which generates a change of the gauge in the Hamiltonian path integral, evaluate it explicitly for connecting two arbitrary Rξ-like gauges in the Yang–Mills theory and establish, after integration over momenta, a coincidence with the Lagrangian path integral [arXiv:1405.0790 [hep-th]], which justifies the unitarity of the S-matrix in the Lagrangian approach.

Relativistic exchange-correlation energy functional: Gauge dependence of the no-pair correlation energy

1998 ◽  
Vol 58 (2) ◽  
pp. 993-1000 ◽  
Author(s):  
A. Facco Bonetti ◽  
E. Engel ◽  
R. M. Dreizler ◽  
I. Andrejkovics ◽  
H. Müller
Keyword(s):  
Correlation Energy ◽  
Pair Correlation ◽  
Energy Functional ◽  
Exchange Correlation ◽  
Gauge Dependence

Gauge dependence of ultraviolet behavior of gauge theories

1974 ◽  
Vol 48 (1) ◽  
pp. 36-38 ◽  
Author(s):  
A. Hosoya ◽  
A. Sato
Keyword(s):  
Gauge Theories ◽  
Gauge Dependence
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