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Related papers: Constraining anomalous $W tb$ and related SMEFT co…

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The electroweak symmetry breaking (EWSB) sector of the Standard Model can be far richer and more interesting than the usual single scalar doublet model. We explore scenarios where the EWSB sector is nearly scale invariant and consequently…

High Energy Physics - Phenomenology · Physics 2009-03-12 JiJi Fan , Walter D. Goldberger , Andreas Ross , Witold Skiba

We investigate single top production in the presence of anomalous Wtb couplings. We explicitly show that, if these couplings arise from gauge invariant effective operators, the only relevant couplings for single top production and decay are…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. A. Aguilar-Saavedra

We compile information from low-energy observables sensitive to flavor-conserving 4-fermion operators with two or four leptons. Our analysis includes data from e+e- colliders, neutrino scattering on electron or nucleon targets, atomic…

High Energy Physics - Phenomenology · Physics 2017-09-13 Adam Falkowski , Martín González-Alonso , Kin Mimouni

The ATLAS and CMS collaborations at the LHC have performed analyses on the existing data sets, studying the case of one vector-like fermion or multiplet coupling to the standard model Yukawa sector. In the near future, with more data…

High Energy Physics - Phenomenology · Physics 2015-02-03 Giacomo Cacciapaglia , Aldo Deandrea , Naveen Gaur , Daisuke Harada , Yasuhiro Okada , Luca Panizzi

As a model independent approach to search for the signals of new physics~(NP) beyond the Standard Model~(SM), the SM effective field theory~(SMEFT) draws a lot of attention recently. The energy scale of a process is an important parameter…

High Energy Physics - Phenomenology · Physics 2023-10-23 Ji-Chong Yang , Jin-Hua Chen , Yu-Chen Guo

The Standard Model effective field theory (SMEFT) is the tool of choice for studying deviations of Higgs couplings from the Standard Model predictions. The SMEFT is an expansion in an infinite tower of higher dimension operators, which is…

High Energy Physics - Phenomenology · Physics 2023-05-12 Sally Dawson , Duarte Fontes , Samuel Homiller , Matthew Sullivan

Higgs decays to gauge boson pairs are a crucial ingredient in the study of Higgs properties, with the decay $H\rightarrow\gamma\gamma$ being particularly sensitive to new physics effects. Assuming all potential new physics occurs at…

High Energy Physics - Phenomenology · Physics 2018-11-26 Sally Dawson , Pier Paolo Giardino

The Wtb vertex can be probed on future colliders in the processes of single top production (LHC, pp mode, NLC, $\gamma e$ mode) and of top pair production (NLC, e^+ e^- mode). We analyse observables sensitive to anomalous Wtb couplings in…

High Energy Physics - Phenomenology · Physics 2011-09-13 E. Boos , M. Dubinin , M. Sachwitz , H. J. Schreiber

We present a map between the tree-level Standard Model Effective Theory (SMEFT) in the Warsaw basis and massive on-shell amplitudes. As a first step, we focus on the electroweak sector without fermions. We describe the Feynman rules for a…

High Energy Physics - Phenomenology · Physics 2020-01-29 Rafael Aoude , Camila S. Machado

We study the sensitivity of the ATLAS experiment to Wtb anomalous couplings in top pair production with semileptonic decay, pp -> t tbar -> W+ b W- bbar, with one of the W bosons decaying leptonically and the other hadronically. Several…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. A. Aguilar-Saavedra , J. Carvalho , N. Castro , A. Onofre , F. Veloso

We study non-standard top quark couplings in the effective field theory approach. All nine dimension-six operators that generate anomalous couplings between the electroweak gauge bosons and the third-generation quarks are included. We…

High Energy Physics - Phenomenology · Physics 2015-06-04 Cen Zhang , Nicolas Greiner , Scott Willenbrock

We study the electroweak dilepton production with two forward jets at the LHC, aiming to measure the anomalous triple gauge couplings in the Effective Field Theory (EFT) approach. This process exhibits a distinctive feature, namely, the…

High Energy Physics - Phenomenology · Physics 2023-05-23 Haeyun Hwang , Ui Min , Junghyeon Park , Minho Son , Jae Hyeok Yoo

The Standard Model effective field theory (SMEFT) provides a general framework to include the dynamics of the beyond standard model physics residing at a certain higher energy scale $\Lambda$. We study the top-quark production along with a…

High Energy Physics - Phenomenology · Physics 2022-12-07 Monoranjan Guchait , Arnab Roy

The effective renormalizable theory describing electromagnetic and strong interactions of quarks of five light flavors ($n_f = 5$ QCD$\times$QED) is considered as a low-energy limit of the full Standard Model. Two-loop relation between the…

High Energy Physics - Phenomenology · Physics 2018-12-31 A. V. Bednyakov

The paper presents a method of modeling events with anomalous fermion-boson couplings by means of an auxiliary vector fields in addition to the SM gauge field. The method allows to simulate anomalous gauge couplings in different approaches,…

High Energy Physics - Phenomenology · Physics 2015-12-03 E. Boos , V. Bunichev , L. Dudko , M. Perfilov

We analyze the compatibility of the hypothesis of third-family quark-lepton unification at the TeV scale with electroweak precision data, lepton flavor universality tests, and high-$p_T$ constraints. We work within the framework of the UV…

High Energy Physics - Phenomenology · Physics 2025-08-08 Lukas Allwicher , Gino Isidori , Javier M. Lizana , Nudzeim Selimovic , Ben A. Stefanek

Effective field theories offer a rationale to classify new physics models based on the size of their contribution to the effective Lagrangian, and therefore to experimental observables. A complete classification can be obtained, at a fixed…

High Energy Physics - Phenomenology · Physics 2023-03-31 G. Guedes , P. Olgoso , J. Santiago

One of the assumptions of simplified models is that there are a few new particles and interactions accessible at the LHC and all other new particles are heavy and decoupled. The effective field theory (EFT) method provides a consistent…

High Energy Physics - Phenomenology · Physics 2021-05-05 Shekhar Adhikari , Ian M. Lewis , Matthew Sullivan

We examine the electroweak breaking mechanism in the minimal supersymmetric standard model (MSSM) using the {\em complete} one-loop effective potential $V_1$. First, we study what is the region of the whole MSSM parameter space (i.e.…

High Energy Physics - Phenomenology · Physics 2008-11-26 B. de Carlos , J. A. Casas

This is a brief summary of the latest searches for virtual effects of new physics in the top sector. In the framework of the Standard Model Effective Field Theory (SMEFT), I show how to resolve the structure of effective couplings by…

High Energy Physics - Phenomenology · Physics 2021-02-10 Susanne Westhoff