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Lepton flavor-violating processes offer interesting possibilities to probe new physics at multi-TeV scale. We discuss those in the framework of effective field theory, emphasizing the role of gluonic operators. Those operators are obtained…

High Energy Physics - Phenomenology · Physics 2017-08-09 Alexey A. Petrov , Dmitry V. Zhuridov

Four-fermion operators with large anomalous dimension may feed down mass to quarks and leptons from a heavy fourth family. No technicolor sector is required. A model illustrates the origin of the large top mass along with quark mass…

High Energy Physics - Phenomenology · Physics 2011-01-27 B. Holdom

New-physics (NP) constraints on first-generation quark-lepton interactions are particularly interesting given the large number of complementary processes and observables that have been measured. Recently, first hints for such NP effects…

High Energy Physics - Phenomenology · Physics 2021-10-29 Andreas Crivellin , Martin Hoferichter , Matthew Kirk , Claudio Andrea Manzari , Luc Schnell

We obtain the constraints on possible anomalous quartic vector-boson vertices arising from the precision measurements at the $Z$ pole. In the framework of $SU(2)_L \otimes U(1)_Y$ chiral Lagrangians, we examine all effective operators of…

High Energy Physics - Phenomenology · Physics 2009-10-28 A. Brunstein , O. J. P. Eboli , M. C. Gonzalez-Garcia

This doctoral dissertation presents several works on nonstandard properties of neutrinos exploiting the synergies between effective field theory and models. The phenomena are first analysed by means of effective operators, which allow to…

High Energy Physics - Phenomenology · Physics 2013-12-03 Alberto Aparici

Effective operators provide a model-independent description of physics beyond the stan- dard model that is particularly useful given the absence of any signs of new physics at the Large Hadron Collider (LHC). We recast previous LHC analyses…

High Energy Physics - Phenomenology · Physics 2018-06-14 Yi Cai , Michael A. Schmidt , German Valencia

The impact of new physics on the interactions of neutrinos with other particles can be parametrized by a set of effective four-fermion operators called non-standard neutrino interactions (NSIs). This NSI framework is useful for studying the…

High Energy Physics - Phenomenology · Physics 2026-04-23 Ayres Freitas , Matthew Low

We analyze the possibility of having new physics effects in the decay rate difference, $\Delta \Gamma_d$, of neutral $B_d$ mesons. Three different sources of enhancement are considered, CKM unitarity violations, beyond standard model…

High Energy Physics - Phenomenology · Physics 2015-01-09 Gilberto Tetlalmatzi-Xolocotzi

We study the experimental constraints on strongly interacting vector-fermions compatible with the relaxion mechanism and investigate any possible tuning. The focus is on a minimal model and low confinement scale. More precisely, we study…

High Energy Physics - Phenomenology · Physics 2017-09-13 Hugues Beauchesne , Enrico Bertuzzo , Giovanni Grilli di Cortona

We study perturbative unitarity constraints on generic interactions between fermion and vector fields, which are allowed to have generic quantum numbers under a $\prod_i SU(N_i) \otimes U(1)$ group. We derive compact expressions for the…

High Energy Physics - Phenomenology · Physics 2023-09-20 Daniele Barducci , Marco Nardecchia , Claudio Toni

We study the leptonic CP violation by employing the complete set of dimension-six pure leptonic effective operators. Connection among the observable at different energy scales can be made by the running of the renormalization group…

High Energy Physics - Phenomenology · Physics 2009-11-11 We-Fu Chang , John N. Ng

The chirality-flipping operators of light fermions are currently poorly constrained by experimental analyses due to the lack of interference with Standard Model (SM) amplitudes in traditional observables. In this work, we propose to…

High Energy Physics - Phenomenology · Physics 2024-04-22 Hao-Lin Wang , Xin-Kai Wen , Hongxi Xing , Bin Yan

We investigate forces induced by the exchange of two light neutrinos between Standard Model (SM) fermions in the presence of effective operators parametrising physics beyond the SM. We first set up a general framework in which we derive the…

High Energy Physics - Phenomenology · Physics 2020-07-07 Patrick D. Bolton , Frank F. Deppisch , Chandan Hati

Both collider searches and direct detections are promising approaches to probe fermionic dark matter. In this paper, we study signatures of four-fermion contact operators involving a dark fermion, an electron, and a quark pair. We show that…

High Energy Physics - Phenomenology · Physics 2025-09-23 Kai Ma

There is growing interest in the development of a muon collider that would make it possible to produce lepton collisions at energies of several TeV. Among others, there can be significant contributions to electroweak gauge boson, Higgs…

High Energy Physics - Phenomenology · Physics 2024-11-22 Daniel Ake , Antonio O. Bouzas , F. Larios

A "muon mass tree" is displayed that contains the excitation systematics for accurately reproducing the masses of the six Standard Model quarks (u,d,s,c,b,t); the heavy leptons; the proton; the phi, J/Psi and Upsilon vector meson thrshold…

High Energy Physics - Phenomenology · Physics 2007-05-23 Malcolm H. Mac Gregor

We consider theories where lepton flavor is violated, in particular concentrating on the four fermion operator consisting of three electrons and a tau. Strong constraints are available from existing searches for tau -> eee, requiring the…

High Energy Physics - Phenomenology · Physics 2015-01-14 Brandon Murakami , Tim M. P. Tait

A review of searches for physics beyond the Standard Model carried out at high energy lepton-hadron and hadron-hadron facilities is presented, with emphasis on topics of interest for future data taking at the upgraded Tevatron $p{\bar p}$…

High Energy Physics - Experiment · Physics 2011-03-23 Masahiro Kuze , Yves Sirois

Focusing on four-Higgs interactions, we analyse the robustness of tree-level-derived positivity bounds on Standard Model effective field theory (SMEFT) operators under quantum corrections. Among other results, we demonstrate that: (i) Even…

High Energy Physics - Phenomenology · Physics 2022-06-29 Mikael Chala , Jose Santiago

We provide updated bounds on non-standard neutrino interactions based on data from the Planck satellite as well as auxiliary cosmological measurements. Two types of models are studied - A Fermi-like 4-point interaction and an interaction…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Maria Archidiacono , Steen Hannestad
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