English
Related papers

Related papers: Extended technicolor contribution to the Zbb verte…

200 papers

In order to explain possible departures from the Standard Model predictions for $b\bar b$ and $c\bar c$ production at $Z$ peak, we propose the existence of a $Z'$ vector boson with enhanced couplings to quarks. We first show that this…

High Energy Physics - Phenomenology · Physics 2011-01-25 P. Chiappetta , J. Layssac , F. M. Renard , C. Verzegnassi

We consider the lepton-flavor violating(LFV) processes $l_{i}\to l_{j}\gamma$ in the framework of topcolor assisted technicolor(TC2) models. We find that the new gauge boson $Z^{\prime}$ predicted by TC2 models can give significantly…

High Energy Physics - Phenomenology · Physics 2018-01-17 Chongxing Yue , Qingjun Xu , Guoli Liu

An extension of the Standard Model is presented that leads to the possible existence of new gauge bosons with masses in the range of a few TeV. Due to the fact that their couplings to Standard Model fermions are strongly suppressed, it is…

High Energy Physics - Phenomenology · Physics 2018-10-31 Carlos Alvarado , Alfredo Aranda

The methods of lattice gauge theory may be applied to gauge theories besides QCD, in fact to any gauge group and any representation of matter fields (as long as the coupling is not chiral). Such theories are useful for model building beyond…

High Energy Physics - Lattice · Physics 2010-02-25 Benjamin Svetitsky

Recent work by Burdman, Lane, and Rador has shown that B-meson mixing places stringent lower bounds on the masses of topgluons and Z' bosons in classic topcolor-assisted technicolor (TC2) models. This paper finds analogous limits on the Z'…

High Energy Physics - Phenomenology · Physics 2009-11-07 Elizabeth H. Simmons

Motivated by $-2 \sigma$ deviation from the Standard Model prediction for the forward--backward asymmetry of $Z \to b \bar{b}$ decay in the LEP data, we explore the anomalous couplings of $Z b \bar{b}$ vertex through the electroweak…

High Energy Physics - Phenomenology · Physics 2009-10-31 Kang Young Lee

In this talk, we discuss the next-to-leading order (NLO) QCD corrections to the associated production of the vector gauge boson (Z/W\pm) and the graviton in the large extra dimension model, namely the ADD model, at the LHC. After a brief…

High Energy Physics - Phenomenology · Physics 2012-01-10 M. C. Kumar , Prakash Mathews , V. Ravindran , Satyajit Seth

We study extensions of the Standard Model with general new vector bosons. The full Standard Model gauge symmetry is used to classify the extra vectors and constrain their couplings. We derive the corresponding effective Lagrangian, valid at…

High Energy Physics - Phenomenology · Physics 2025-02-05 F. del Aguila , J. de Blas , M. Perez-Victoria

When technicolor (TC), QCD, extended technicolor (ETC) and other interactions become coupled through their different Schwinger-Dyson equations, the solution of these equations are modified compared to those of the isolated equations. The…

High Energy Physics - Phenomenology · Physics 2020-07-22 A. A. Natale , A. Doff

By extending the standard gauge group to $SU(3)_c \times SU(2)_L \times U(1)_Y \times U(1)_X$ with $X$ charges carried only by the third family we accommodate the LEP measurement of $R_b$ and predict a potentially measurable discrepancy in…

High Energy Physics - Phenomenology · Physics 2016-09-06 P. H. Frampton

Since the pioneering work of Eichten and Lane it has been known that the scale of the interactions responsible for the generation of the strange-quark mass in extended technicolor theories must, absent any "GIM-like" mechanism for…

High Energy Physics - Lattice · Physics 2014-11-21 R. Sekhar Chivukula , Elizabeth H. Simmons

Technicolor and other theories of dynamical electroweak symmetry breaking invoke chiral symmetry breaking triggered by strong gauge-dynamics, analogous to that found in QCD, to explain the observed W, Z, and fermion masses. In this talk we…

High Energy Physics - Lattice · Physics 2011-05-18 R. Sekhar Chivukula , Elizabeth H. Simmons

We consider the extension of the standard model with an arbitrary number of U(1) gauge fields coupled to baryon-minus-lepton number and/or hypercharge. Under the assumption that A^b_FB from the LEP1 experiment is an unlucky fluctuation, we…

High Energy Physics - Phenomenology · Physics 2011-03-23 A. Ferroglia , A. Lorca , J. J. van der Bij

In the context of topcolor-assisted technicolor (TC2) models, we examine the flavor changing (FC) Z decay $Z\to b\bar{s}(\bar{b}s)$ and calculate the contributions of the new particles predicted by TC2 models to the branching ratio Br($Z\to…

High Energy Physics - Phenomenology · Physics 2009-11-07 Chongxing Yue , Hong Li , Hongjie Zong

The new gauge boson $Z^{\prime}$ predicted by the strong top dynamical symmetry breaking models has significant contributions to the lepton flavor changing process $\mu\longrightarrow 3e $. We consider the bound on the mass of the new gauge…

High Energy Physics - Phenomenology · Physics 2009-10-31 Chongxing Yue , Guoli Liu , Jiantao Li

Evidences of a discrete symmetry behind the pattern of lepton mixing are analyzed. The program of "symmetry building" is outlined. Generic features and problems of realization of this program in consistent gauge models are formulated. The…

High Energy Physics - Phenomenology · Physics 2015-05-27 Alexei Yu Smirnov

In view of the recent and future electroweak precision data accumulated at LEP and SLC, we systematically analyze possible new physics effects that may occur in the leptonic sector within the context of $SU(2)_R \times SU(2)_L \times…

High Energy Physics - Phenomenology · Physics 2016-09-01 Apostolos Pilaftsis

We address the question of the possible existence of massive gauge bosons beyond the $W^{\pm}$ and $Z^{0}$ of the standard model. Our intuitive and aesthetic approach is based on quiver theory. Examples thereof arise, for example, from…

High Energy Physics - Phenomenology · Physics 2013-12-12 Paul Howard Frampton

We study the possibility of gauging the Standard Model flavor group. Anomaly cancellation leads to the addition of fermions whose mass is inversely proportional to the known fermion masses. In this case all flavor violating effects turn out…

High Energy Physics - Phenomenology · Physics 2011-01-28 Benjamín Grinstein , Michele Redi , Giovanni Villadoro

This talk gives an overview, aimed at non-experts, of the recent progress on the studies of technicolor models on the lattice. Phenomenologically successful technicolor models require walking coupling; thus, an emphasis is put on the…

High Energy Physics - Lattice · Physics 2011-06-15 Kari Rummukainen