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Related papers: Electroweak constraints on flavorful effective the…

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We present Standard Model predictions for the complete set of phenomenologically relevant electroweak precision pseudo-observables related to the Z-boson: the leptonic and bottom-quark effective weak mixing angles $\sin^2\theta_{\rm…

High Energy Physics - Phenomenology · Physics 2020-01-13 Ievgen Dubovyk , Ayres Freitas , Janusz Gluza , Tord Riemann , Johann Usovitsch

We find that, at order alpha_s, the partial width of Z^0 to heavy flavors receives a power correction from a novel QCD mechanism, which is not suppressed by inverse powers of M_Z, but only by two unknown O(\lambdaqcd/m) constants. The…

High Energy Physics - Phenomenology · Physics 2007-05-23 Yu Jia

We discuss how models of electroweak symmetry breaking based on strong dynamics lead to observable contributions to the Z-boson decay width to bbbar pairs even in the absence of any extended sector responsible for dynamical generation of…

High Energy Physics - Phenomenology · Physics 2012-11-22 Hidenori S. Fukano , Kimmo Tuominen

Possible non-standard tqZ couplings, where q=c or u, originated from general flavor-changing-neutral-current interactions are studied model-independently using the effective Lagrangian consisting of several SU(3)xSU(2)xU(1) invariant…

High Energy Physics - Phenomenology · Physics 2020-04-21 Zenro Hioki , Kazumasa Ohkuma , Akira Uejima

We study the simplest generic extension of the Standard Model which allows for conventional electroweak baryogenesis, through the addition of dimension six operators in the Higgs sector. At least one such operator is required to be CP-odd,…

High Energy Physics - Phenomenology · Physics 2008-11-26 Stephan J. Huber , Maxim Pospelov , Adam Ritz

A complete set of dimension-6 effective contact interactions involving Higgs, gauge bosons and quarks is studied. Limits on the coefficients of these new operators are obtained from the experimental values of the $Z$ and $W$ gauge bosons…

High Energy Physics - Phenomenology · Physics 2011-01-25 Alexander Belyaev , Rogerio Rosenfeld

We consider renormalisable models extended in the scalar sector by a generic scalar field in addition to the standard model Higgs boson field, and work out the effective theory for the latter in the decoupling limit. We match the full…

High Energy Physics - Phenomenology · Physics 2015-10-28 Cheng-Wei Chiang , Ran Huo

A fully generic treatment of electric dipole moments (EDMs) is presented in the CP-violating and flavor-conserving weak effective field theory (WET) with five flavors of quarks and three flavors of leptons. We systematically analyze leading…

High Energy Physics - Phenomenology · Physics 2024-06-13 Jacky Kumar , Emanuele Mereghetti

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 provide a set of theoretical constraints on models in which the Standard Model field content is extended by vector-like fermions and in some cases also by a real scalar singlet. Our approach is based on the study of electroweak vacuum…

High Energy Physics - Phenomenology · Physics 2024-10-08 Amit Adhikary , Marek Olechowski , Janusz Rosiek , Michal Ryczkowski

We consider a non-linear realization of the electroweak symmetry-breaking pattern $SU(2)_L\times SU(2)_R/SU(2)_{L+R}$ to construct a low-energy effective theory, later extended by the inclusion of heavy new-physics resonances. After…

High Energy Physics - Phenomenology · Physics 2020-12-24 Juan Jose Sanz-Cillero , Antonio Pich , Ignasi Rosell

The measurements carried out at LEP and SLC projected us into the precision era of electroweak physics. This has also been relevant in the theoretical interpretation of LHCb and Belle measurements of rare $B$ semileptonic decays, paving the…

High Energy Physics - Phenomenology · Physics 2021-02-05 Lina Alasfar , Aleksandr Azatov , Jorge de Blas , Ayan Paul , Mauro Valli

A novel approach to study electroweak physics at one-loop level in generic ${\rm SU(2)_L \times U(1)_Y}$ theories is introduced. It separates the 1-loop corrections into two pieces: process specific ones from vertex and box contributions,…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. Hagiwara , D. Haidt , C. S. Kim , S. Matsumoto

We study the combined effects of both strong and electroweak dimension six effective operators on flavour changing top quark physics at the LHC. Analytic expressions for the cross sections and decay widths of several flavour changing…

High Energy Physics - Phenomenology · Physics 2008-11-26 P. M. Ferreira , R. B. Guedes , R. Santos

We investigate the electroweak precision constraints on the recently proposed Lee-Wick Standard Model at tree level. We analyze low energy, Z-pole (LEP1/SLC) and LEP2 data separately. We derive the exact tree level low energy and Z-pole…

High Energy Physics - Phenomenology · Physics 2009-03-12 Thomas E. J. Underwood , Roman Zwicky

Using the framework of deconstruction, we construct simple, weakly-coupled supersymmetric models that explain the Standard Model flavor hierarchy and produce a flavorful soft spectrum compatible with precision limits. Electroweak symmetry…

High Energy Physics - Phenomenology · Physics 2015-05-27 Nathaniel Craig , Daniel Green , Andrey Katz

There are theoretical and phenomenological motivations that there may exist additional heavy Z' bosons with family non-universal couplings. Flavor mixing in the quark and lepton sectors will then lead to flavor changing couplings of the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Paul Langacker , Michael Plumacher

In these lectures we give a discussion of the structure of the electroweak standard model and its quantum corrections for tests of the electroweak theory. The predictions for the vector boson masses, neutrino scattering cross sections and…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. Hollik

We briefly review the limits on new interactions implied by electroweak precision data. Special attention is payed to the bounds on the Higgs boson mass. We also comment on the required cancellation among the new contributions to precisely…

High Energy Physics - Phenomenology · Physics 2015-05-28 F. del Aguila , J. de Blas

Small neutrino masses can arise in some grand unified models or superstring theories. We consider a model with an enhanced fermion sector containing Dirac neutral heavy leptons. The dependence on the mass and mixing parameters of these new…

High Energy Physics - Phenomenology · Physics 2016-09-01 G. Bhattacharya , Pat Kalyniak , I. Melo