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In an effective Lagrangian description of physics beyond the standard model, gluonic couplings of leptons that respect the symmetries of the standard model occur in operators of dimension eight. Normally the effect of such operators is much…

High Energy Physics - Phenomenology · Physics 2012-05-29 Hugh Potter , German Valencia

We examine dimension-six extensions of the standard electroweak Lagrangian which are invariant under local \suu -transformations. The dimension-four trilinear and quadrilinear effective interactions of the vector bosons with one another are…

High Energy Physics - Phenomenology · Physics 2009-10-22 Carsten Grosse-Knetter , Ingolf Kuss , Dieter Schildknecht

A comprehensive analysis of the lepton flavor violating (LFV) decays Z-->li lj is presented within the effective Lagrangian approach. Both the decoupling and nondecoupling scenarios are explored. The experimental constraints from li --> lj…

High Energy Physics - Phenomenology · Physics 2009-11-07 A. Flores-Tlalpa , J. M. Hernandez , G. Tavares-Velasco , J. J. Toscano

In a model independent framework, the effects of new physics at the electroweak scale can be parametrized in terms of an effective Lagrangian expansion. Assuming the $SU(2)_L x U(1)_Y$ gauge symmetry is linearly realized, the expansion at…

High Energy Physics - Phenomenology · Physics 2014-11-21 J. Gonzalez-Fraile

We construct the full p6 order chiral Lagrangians for the unitary group and special unitary groups, including nf-, three- and two-flavor cases, all bilinear currents (scalar, pseudoscalar, vector, axial-vector and tensor currents) and theta…

High Energy Physics - Phenomenology · Physics 2014-05-07 Shao-Zhou Jiang , Feng-Jun Ge , Qing Wang

A SU(4) flavor symmetrical Lagrangian is constructed for the interaction of the pseudo-scalar mesons with the vector mesons. SU(4) symmetry is broken to SU(3) by suppression of terms in the Lagrangian where the interaction should be driven…

High Energy Physics - Phenomenology · Physics 2008-11-26 D. Gamermann , E. Oset

We present realistic models of flavor in SU(5) and SO(10) grand unified theories (GUTs). The models are renormalizable and do not require any exotic representations in order to accommodate the necessary GUT breaking effects in the Yukawa…

High Energy Physics - Phenomenology · Physics 2021-02-03 Gero von Gersdorff

We present an effective Lagrangian formalism for the calculation of flavour changing neutral and charged scalar currents in weak decays including $SU(2)\times U(1)$ symmetry breaking effects and the effects of the electroweak couplings…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. J. Buras , P. H. Chankowski , J. Rosiek , L. Slawianowska

The dimension-six CP-conserving $SU_L(2)\times U_Y(1)$ invariant operators involving the tau lepton are studied. It leads to the new physics effects to the lepton flavor violation (LFV) and lepton flavor-changing neutral current(FCNC). With…

High Energy Physics - Phenomenology · Physics 2007-05-23 T. Huang , Z. -H. Lin , X. Zhang

We derive model-independent constraints arising from the Z and W boson observables on dimension six operators in the effective theory beyond the Standard Model. In particular, we discuss the generic flavor structure for these operators as…

High Energy Physics - Phenomenology · Physics 2015-08-04 Aielet Efrati , Adam Falkowski , Yotam Soreq

We present a study of anomalous electroweak gauge-boson couplings which can be measured in e+e- and gamma gamma collisions at a future linear collider like ILC. We consider the gauge-boson sector of a locally SU(2) x U(1) invariant…

High Energy Physics - Phenomenology · Physics 2009-01-07 O. Nachtmann , F. Nagel , M. Pospischil , A. Utermann

We use recent experimental data on charmed mesons to constrain three coupling constants in the effective lagrangian describing the interactions of excited heavy-light mesons with light pseudoscalar mesons at order $m_Q^{-1}$. Predictions in…

High Energy Physics - Phenomenology · Physics 2009-11-11 P. Colangelo , F. De Fazio , R. Ferrandes

We study the dimension-6 quark anomalous electroweak couplings in the formulation of linearly realized effective Lagrangian. We investigate the constraints on these anomalous couplings from the $pp \rightarrow W^+W^-$ process in detail at…

High Energy Physics - Phenomenology · Physics 2016-03-30 Sheng-Zhi Zhao , Bin Zhang

T-odd correlations in $Wj$ production at the LHC have been studied recently as a way to measure a phase produced by QCD at NLO by Frederix et. al. That study found that the induced asymmetry could be observed with 20 fb$^{-1}$ of 8 TeV…

High Energy Physics - Phenomenology · Physics 2017-10-18 Hai Tao Li , German Valencia

Parameters and light fields of the QCD Lagrangian with two heavy flavours, b and c, are related to those in the low-energy effective theory without these flavours, to three-loop accuracy taking into account the exact dependence on m_c/m_b.…

High Energy Physics - Phenomenology · Physics 2012-05-29 Andrey Grozin , Maik Höschele , Jens Hoff , Matthias Steinhauser

Effective interaction models of quantum chromodynamics, based on quark degrees of freedom, have been successfully employed to compute the properties of a large array of ground and excited meson and baryon states, along with their…

High Energy Physics - Phenomenology · Physics 2026-01-12 Fábio L. Braghin , Bruno El-Bennich , Fernando E. Serna

The most general chiral Lagrangian for electroweak interactions with the complete set of $SU(2)_L\times U(1)_Y$ invariant operators up to dimension four is considered. The two-point and three-point functions with external gauge fields are…

High Energy Physics - Phenomenology · Physics 2009-10-22 M. J. Herrero , E. Ruiz Morales

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

These lectures provide an overview of Quantum Chromodynamics (QCD), the $SU(3)_C$ gauge theory of the strong interactions. After briefly reviewing the empirical considerations which lead to the introduction of {\it colour}, the QCD…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Pich

We construct a manifestly gauge invariant Lagrangian in 3+1 dimensions for N Kaluza-Klein modes of an SU(m) gauge theory in the bulk. For example, if the bulk is 4+1, the effective theory is \Pi_{i=1}^{N+1} SU(m)_i with N chiral (\bar{m},m)…

High Energy Physics - Theory · Physics 2009-11-07 Christopher T. Hill , Stefan Pokorski , Jing Wang