Related papers: Two-loop renormalization of the CPT-even Lorentz-v…
This paper is dedicated to the study of interactions between external sources for the electromagnetic field in a model which exhibits Lorentz symmetry breaking. We investigate such interactions in the CPT-even photon sector of the Standard…
CPT and Lorentz violation in the photon sector is described within the minimal Standard-Model Extension by a dimension-3 Chern-Simons-like operator parametrized by a four-vector parameter $k_{AF}$ that has been very tightly bounded by…
A theoretical study of possible signals for CPT and Lorentz violation arising in hydrogen and antihydrogen spectroscopy is described. The analysis uses a CPT- and Lorentz-violating extension of quantum electrodynamics, obtained from a…
We discuss conceptual aspects of renormalization in the context of effective field theories for the two-nucleon system. It is shown that, contrary to widespread belief, renormalization scheme dependence of the scattering amplitude can only…
We search for novel Lorentz- and CPT-violating field theories, beyond those contained in the superficially renormalizable standard model extension. We find a new class of scalar field self-interactions which are nonpolynomial in form,…
Assuming Lorentz symmetry is broken by some fixed vector background, we study the spinor electrodynamics modified by two dimension-five Lorentz-violating interactions between fermions and photons. The effective polarization and…
We investigate a specific set of two-loop self-energy corrections involving squared decay rates and point out that their interpretation is highly problematic. The corrections cannot be interpreted as radiative energy shifts in the usual…
We consider Lorentz-violating operators induced at the loop level in softly-broken supersymmetric noncommutative QED. Dangerous operators forbidden in the supersymmetric limit are generated via finite corrections, with the scale of…
We investigate the two-loop effective potential for both minimally and non-minimally coupled Maxwell-Chern-Simons theories. The non-minimal gauge interaction represents the magnetic moment interaction between a charged scalar and the…
In order to investigate the systematics of the loop expansion in high temperature gauge theories beyond the leading order hard thermal loop (HTL) approximation, we calculate the two-loop electron proper self-energy in high temperature QED.…
Asymptotic single-particle states in quantum field theories with small departures from Lorentz symmetry are investigated perturbatively with focus on potential phenomenological ramifications. To this end, one-loop radiative corrections for…
We study the asymptotic behaviour of two-loop electroweak corrections at energies Q >> M_W, where logarithms of the type ln(Q/M_W) become dominant. The calculation of the leading and next-to-leading logarithmic terms for massless and…
The classification of Lorentz- and CPT-violating operators in nonabelian gauge field theories is performed. We construct all gauge-invariant terms describing propagation and interaction in the action for fermions and gauge fields.…
In this work, we compute analytically the infrared divergences of massless O($N$) self-interacting scalar field theories with Lorentz violation, which are exact in the Lorentz-violating $K_{\mu\nu}$ coefficients, for evaluating the…
An overview of recent progress on testing Lorentz and CPT symmetry using Penning traps is presented. The theory of quantum electrodynamics with Lorentz-violating operators of mass dimensions up to six is summarized. Dominant shifts in the…
We obtain information on the QED photon amplitudes at high orders in perturbation theory starting from known results on the QED effective Lagrangian in a constant electric field. A closed-form all-order result for the weak field limit of…
We compute the on-shell wave function renormalization constant to four-loop order in QCD and present numerical results for all coefficients of the SU$(N_c)$ colour factors. We extract the four-loop HQET anomalous dimension of the heavy…
The quantum action for a three-dimensional real sextic model using the background field method is considered. Four-loop renormalization of this model is performed with a cutoff regularization in the coordinate representation. The…
From the effects of the Lorentz symmetry violation in the CPT-even gauge sector of Standard Model Extension, we establish a possible scenario where an analogue of the He-McKellar-Wilkens effect can stem from. Besides, we build quantum…
We present the second part of a systematic calculation of the two-loop anomalous dimensions for the low-energy effective field theory below the electroweak scale (LEFT): the baryon-number-violating sector at dimension six in the power…