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We present general one-loop contributions to the decay processes $H\rightarrow f\bar{f}\gamma$ including all possible the exchange of the additional heavy vector gauge bosons, heavy fermions, and charged (also neutral) scalar particles in…

High Energy Physics - Phenomenology · Physics 2022-04-20 Vo Van On , Dzung Tri Tran , Chi Linh Nguyen , Khiem Hong Phan

We exploit a recent computation of one graviton loop corrections to the self-mass [1] to quantum-correct the field equation for a massless, conformally coupled scalar on a de Sitter background. With the obvious choice for the finite part of…

General Relativity and Quantum Cosmology · Physics 2021-06-02 D. Glavan , S. P. Miao , T. Prokopec , R. P. Woodard

In this paper we evaluate the self-energy of the vector mesons at one loop in our recently proposed subtraction scheme for massive nonlinearly realized SU(2) Yang-Mills theory. We check the fulfillment of physical unitarity. The resulting…

High Energy Physics - Theory · Physics 2012-05-24 Daniele Bettinelli , Ruggero Ferrari , Andrea Quadri

We revisit the proof of equivalence of one loop expressions for fermion self-energy and vertex correction in light-front QED and Covariant QED at the Feynman diagram level and generalize, to all components, the proof of equivalence for the…

High Energy Physics - Theory · Physics 2018-07-11 Deepesh Bhamre , Anuradha Misra , Vivek Kumar Singh

We derive the scattering amplitude for Goldstone bosons of chiral symmetry off the pseudoscalar charmed mesons up to leading one-loop order in a covariant chiral effective field theory, using the so-called extended-on-mass-shell…

High Energy Physics - Phenomenology · Physics 2015-11-09 De-Liang Yao , Meng-Lin Du , Feng-Kun Guo , Ulf-G. Meißner

We apply ideas motivated by string theory to improve the calculational efficiency of one-loop weak interaction processes with massive external gauge bosons. In certain cases ``supersymmetry'' relations between diagrams with a fermion loop…

High Energy Physics - Phenomenology · Physics 2009-10-22 Z. Bern , A. G. Morgan

We consider the three fundamental one loop Feynman diagrams of QED viz. vertex correction, fermion self-energy and vacuum polarization in the light-front gauge and discuss the equivalence of their standard covariant expressions with the…

High Energy Physics - Theory · Physics 2022-03-29 Deepesh Bhamre , Anuradha Misra

We survey several mathematical developments in the holonomy approach to gauge theory. A cornerstone of this approach is the introduction of group structures on spaces of based loops on a smooth manifold, relying on certain homotopy…

Mathematical Physics · Physics 2022-01-03 Claudio Meneses

We show that, in analyzing differential equations obeyed by one-loop gauge theory amplitudes, one must take into account a certain holomorphic anomaly. When this is done, the results are consistent with the simplest twistor-space picture of…

High Energy Physics - Theory · Physics 2010-04-07 Freddy Cachazo , Peter Svrcek , Edward Witten

I describe a novel covariant formulation of massive gauge theories in which the longitudinal polarization vectors do not grow with the energy. Therefore in the present formalism, differently from the ordinary one, the energy and coupling…

High Energy Physics - Phenomenology · Physics 2014-09-12 Andrea Wulzer

We have calculated the $W$-loop contribution to the amplitude of the decay $H\rightarrow Z+\gamma$ in two different methods: 1) in the $R_\xi$-gauge using dimensional regularization (DimReg), and 2) in the unitary gauge through the…

High Energy Physics - Phenomenology · Physics 2018-05-09 I. Boradjiev , E. Christova , H. Eberl

We derive bounds on nine dimension-six operators involving electroweak gauge bosons and the Higgs boson from precision electroweak data. Four of these operators contribute at tree level, and five contribute only at one loop. Using the full…

High Energy Physics - Phenomenology · Physics 2013-07-24 Harrison Mebane , Nicolas Greiner , Cen Zhang , Scott Willenbrock

We compute the one-loop matching between the Standard Model Effective Field Theory and the low-energy effective field theory below the electroweak scale, where the heavy gauge bosons, the Higgs particle, and the top quark are integrated…

High Energy Physics - Phenomenology · Physics 2022-11-21 Wouter Dekens , Peter Stoffer

We calculate the 1-loop effective potential of an Abelian Higgs model within the R_{\xi/\sigma} class of non-linear gauges that preserves the Higgs-boson low-energy theorem. The R_{\xi/\sigma} gauge involves two gauge-fixing parameters \xi…

High Energy Physics - Phenomenology · Physics 2009-03-31 Lisa P. Alexander , Apostolos Pilaftsis

The one loop effects of two dimension-six operators on gauge boson self energies are computed within an effective field theory framework. These self energies are translated into effects on precision electroweak observables, and bounds are…

High Energy Physics - Phenomenology · Physics 2015-06-15 Harrison Mebane , Nicolas Greiner , Cen Zhang , Scott Willenbrock

We study one loop structure of the scalar sector of non-linear electroweak chiral Lagrangian (EWChL) with a light (composite) H-boson up to four derivatives. First, we introduce relevant Lagrangian terms in general parametrization of…

High Energy Physics - Phenomenology · Physics 2015-09-22 K. Kanshin

The Higgs decay $H\to \gamma\gamma$ duo to the virtual $W$-loop effect is revisited in the unitary gauge by using the symmetry-preserving and divergent-behavior-preserving loop regularization method, which is realized in the four…

High Energy Physics - Phenomenology · Physics 2012-04-12 Da Huang , Yong Tang , Yue-Liang Wu

Applying effective Lagrangian method and on-shell scheme, we analyze the electroweak corrections to the rare decay $b\rightarrow s+\gamma$ from some special two loop diagrams in which a closed heavy fermion loop is attached to the virtual…

High Energy Physics - Phenomenology · Physics 2014-11-21 Xiu-Yi Yang , Tai-Fu Feng

We calculate one-loop R-parity-violating couplings corrections to the processes $H^-\to \tau\bar{\nu_\tau}$ and $H^-\to b\bar{t}$. We find that the corrections to the $H^-\to \tau\bar{\nu_\tau}$ decay mode are generally about 0.1%, and can…

High Energy Physics - Phenomenology · Physics 2014-11-18 Yi Ping Song , Chong Sheng Li , Qiang Li , Jian Jun Liu

One-loop counterterms are computed in the first order formalism for the Einstein-Hilbert action with a minimally coupled scalar field using the background field method and the heat kernel technique. The {\em off-shell} divergent piece in…

High Energy Physics - Theory · Physics 2021-09-14 Enrique Alvarez , Jesus Anero , Raquel Santos-Garcia