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Related papers: Constraining CPT-odd nonminimal interactions in th…

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We consider the three CP-conserving dimension-6 operators that encode the leading new-physics effects in the triple gauge couplings. The contributions to the standard-model electromagnetic dipole and semi-leptonic vector and axial-vector…

High Energy Physics - Phenomenology · Physics 2015-09-11 Christoph Bobeth , Ulrich Haisch

We consider hadronic top quark pair production and pair production in association with a photon or a $Z$ boson to probe electroweak dipole couplings in $t\bar{b}W$, $t\bar{t}\gamma$ and $t\bar{t}Z$ interactions. We demonstrate how…

High Energy Physics - Phenomenology · Physics 2016-09-21 Markus Schulze , Yotam Soreq

We establish constraints on a general four-fermion contact interaction from precise measurements of electroweak parameters. We compute the one-loop contribution for the leptonic $Z$ width, anomalous magnetic, weak-magnetic, electric and…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. C. Gonzalez-Garcia , A. Gusso , S. F. Novaes

We have studied a (1+2)-dimensional Lorentz-violating model which is obtained from the dimensional reduction of the nonbirefringent sector of the CPT-even electrodynamics of the standard model extension (SME). The planar theory contains a…

High Energy Physics - Theory · Physics 2012-03-08 Rodolfo Casana , Manoel M. Ferreira , Roemir P. M. Moreira

In this work, we study a model in nonlinear electrodynamics in the presence of a CPT-even term that violates Lorentz symmetry. The Lorentz-breaking vector, in addition to the usual background magnetic field, produces interesting effects in…

High Energy Physics - Theory · Physics 2024-05-24 E. Neres Júnior , J. C. C. Felipe , A. P. Baêta Scarpelli

Low-energy Lorentz-invariant quantities could receive contributions from a fundamental theory producing small Lorentz-violating effects. Within the Lorentz-violating extension of quantum electrodynamics, we investigate, perturbatively, the…

High Energy Physics - Phenomenology · Physics 2014-03-20 A. Moyotl , H. Novales-Sánchez , J. J. Toscano , E. S. Tututi

Lorentz and CPT violation in the photon sector with the operators of arbitrary mass dimension has been proposed in the context of Standard-Model Extension. The CPT-odd subset of this enlarged model is investigated from a quantum-field…

High Energy Physics - Phenomenology · Physics 2016-08-04 Soner Albayrak , Ismail Turan

We perform a comparative study of the reach of future $e^+e^-$ collider options for the scale of non-resonant new physics effects in the top quark sector, phrased in the language of higher-dimensional operators. Our focus is on the…

High Energy Physics - Phenomenology · Physics 2017-10-26 Christoph Englert , Michael Russell

In the present paper we study some new classical Lorentz violating effects in planar electrodynamics due to the presence of stationary point-like field sources. Starting from the Carroll-Field-Jackiw model defined in (3+1) dimensions, which…

High Energy Physics - Theory · Physics 2024-01-11 L. H. C. Borges , A. F. Ferrari , P. H. O. da Silva , F. A. Barone

We calculate the typical size of loop corrections to electroweak observables arising from non-standard $Z {\overline t } t$ and $W t b$ vertices. We use an effective Lagrangian formalism based on the electroweak gauge group $SU(2)_L\times…

High Energy Physics - Phenomenology · Physics 2009-10-28 S. Dawson , G. Valencia

The success of the quantum level predictions of the Standard Model on the $Z$ boson properties, on $\mw$ and on $\mt$, which makes use of the muon lifetime as an input, implies a stringent constraint on new physics contributions to the…

High Energy Physics - Phenomenology · Physics 2009-10-30 Kaoru Hagiwara , Seiji Matsumoto

We study the CP-violating (CPV) neutral triple gauge couplings (nTGCs) that can be realized via dimension-8 operators in the Standard Model Effective Field Theory (SMEFT). We present a new formulation of the CPV nTGC form factors that is…

High Energy Physics - Phenomenology · Physics 2026-04-10 John Ellis , Hong-Jian He , Rui-Qing Xiao

The standard model weak interactions can be described by four-fermion V-A operators at low energies. New physics at the TeV scale can, however, generate the other Lorentz structures. In this talk, we review the constraints on such…

High Energy Physics - Lattice · Physics 2012-04-02 Tanmoy Bhattacharya , Rajan Gupta , Anosh Joseph , Huey-Wen Lin , Saul D. Cohen

Radiative corrections arising from Lorentz violation in the fermion sector induce a nonzero amplitude for vacuum photon splitting. At one loop, the on-shell amplitude acquires both CPT-even and CPT-odd contributions forbidden in…

High Energy Physics - Phenomenology · Physics 2009-09-25 Alan Kostelecky , Austin Pickering

An investigation is performed of the Lorentz-violating electrodynamics extracted from the renormalizable sector of the general Lorentz- and CPT-violating standard-model extension. Among the unconventional properties of radiation arising…

High Energy Physics - Phenomenology · Physics 2009-09-25 Alan Kostelecky , Matthew Mewes

A study on the effective anomalous interactions, up to dimension 5, of the top quark with the electroweak gauge bosons is made in the non-linear Chiral Lagrangian approach. Bounds on the anomalous dimension four terms are obtained from…

High Energy Physics - Phenomenology · Physics 2007-05-23 F. Larios , Ehab Malkawi , C. -P. Yuan

In this paper, we explicitly calculate the lower CPT-even one-loop quantum corrections in nonminimal Lorentz-violating spinor QED with all possible CPT-even dimension-5 operators. Within our calculations, we restrict ourselves to the cases…

High Energy Physics - Theory · Physics 2024-01-19 T. Mariz , M. Melo , J. R. Nascimento , A. Yu. Petrov

We constrain $C\!P$-violating charged and neutral anomalous triple gauge couplings using LHC measurements and projections of diboson and VBF $Vjj$ production, both with subsequent leptonic decays. For triple gauge couplings involving $W$…

High Energy Physics - Phenomenology · Physics 2021-04-28 Anke Biekötter , Parisa Gregg , Frank Krauss , Marek Schönherr

Constraints on possible Lorentz symmetry violation (LV) of order E/M_Planck for electrons and photons in the framework of effective field theory (EFT) are discussed. Using (i) the report of polarized MeV emission from GRB021206 and (ii) the…

Astrophysics · Physics 2009-11-10 T. Jacobson , S. Liberati , D. Mattingly , F. W. Stecker

A study on effective anomalous interactions up to dimension 5 of the top quark with the electroweak gauge bosons is made in the non-linear Chiral Lagrangian approach. Bounds on the anomalous dimension four terms are obtained from their…

High Energy Physics - Phenomenology · Physics 2014-11-17 F. Larios , Ehab Malkawi , C. -P. Yuan