Electroweak interaction

About: Electroweak interaction is a research topic. Over the lifetime, 16333 publications have been published within this topic receiving 468927 citations. The topic is also known as: electroweak force.

How can a heavy Higgs boson be consistent with the precision electroweak measurements

Abstract: The fit of precision electroweak data to the Minimal Standard Model currently gives an upper limit on the Higgs boson mass of 170 GeV at 95% confidence. Nevertheless, it is often said that the Higgs boson could be much heavier in more general models. In this paper, we critically review models that have been proposed in the literature that allow a heavy Higgs boson consistent with the precision electroweak constraints. All have unusual features, and all can be distinguished from the Minimal Standard Model either by improved precision measurements or by other signatures accessible to next-generation colliders.

LHC signals for warped electroweak charged gauge bosons

Abstract: We study signals at the LHC for the Kaluza-Klein (KK) excitations of electroweak charged gauge bosons in the framework of the standard model (SM) fields propagating in the bulk of a warped extra dimension Such a scenario can solve both the Planck-weak and flavor hierarchy problems of the SM There are two such charged states in this scenario with couplings to light quarks and leptons being suppressed relative to those in the SM, whereas the couplings to top/bottom quarks are enhanced, similar to the case of electroweak neutral gauge bosons previously studied However, unlike the case of electroweak neutral gauge bosons, there is no irreducible QCD background (including pollution from possibly degenerate KK gluons) for decays to top+bottom final states so that this channel is useful for the discovery of the charged states Moreover, decays of electroweak charged gauge bosons to longitudinal W, Z and Higgs are enhanced just as for the neutral bosons However, unlike for the neutral gauge bosons, the purely leptonic (and hence clean) decay mode of the WZ is fully reconstructible so that the ratio of the signal to the SM (electroweak) background can potentially be enhanced by restricting to the resonance region more efficiently Wemore » show that such final states can give sensitivity to 2(3) TeV masses with an integrated luminosity of 100(300) fb{sup -1} We emphasize that improvements in discriminating a QCD jet from a highly boosted hadronically decaying W, and a highly boosted top jet from a bottom jet will enhance the reach for these KK particles, and that the signals we study for the warped extra dimensional model might actually be applicable also to a wider class of nonsupersymmetric models of electroweak symmetry breaking« less

Dimension-8 Operators in the Standard Model Effective Field Theory

Abstract: We present a complete basis of dimension-8 operators in the Standard Model Effective Field Theory. Attention is paid to operators that vanish in the absence of flavor structure. The 44,807 operators are encoded in 1,029 Lagrangian terms. We also briefly discuss a few aspects of phenomenology involving dimension-8 operators, including light-by-light scattering and electroweak precision data.

A Strong Sector at the LHC: Top Partners in Same-Sign Dileptons

Abstract: Heavy partners of the top quark are a common prediction of many models in which a new strongly-coupled sector is responsible for the breaking of the electroweak symmetry. In this paper, we investigate their experimental signature at the LHC, focusing on the particularly clean channel of same-sign dileptons. We show that, thanks to a strong interaction with the top quark which allows them to be singly produced at a sizable rate, the top partners will be discovered at the LHC if their mass is below 1.5 TeV, higher masses being possible in particularly favorable (but plausible) situations. Since the partners are expected to be lighter in both the Higgsless and composite-Higgs scenarios, then one of same-sign dileptons is found to be a very promising channel in which these models could be tested. We also discuss several experimental signatures which would allow, after the discovery of the excess, to attribute it uniquely to the top partners production and to measure the relevant physical parameters, i.e. the top partners' masses and couplings. We believe that our results constitute a valid starting point for a more detailed experimental study.