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Related papers: Effective Lagrangian for Charged Higgs Couplings

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We consider a self-interacting scalar field theory in a slowly varying gravitational background field. Using zeta-function regularization and heat-kernel techniques, we derive the one-loop effective Lagrangian up to second order in the…

High Energy Physics - Theory · Physics 2009-10-22 Klaus Kirsten , Guido Cognola , Luciano Vanzo

We derive constraints on the sign of couplings in an effective Higgs Lagrangian using prime principles such as the naturalness principle, global symmetries, and unitarity. Specifically, we study four dimension-six operators, O_H, O_y, O_g,…

High Energy Physics - Phenomenology · Physics 2010-05-12 Ian Low , Riccardo Rattazzi , Alessandro Vichi

In this work we study the $\gamma\gamma\to W^+_L W^-_L$ and $\gamma\gamma\to Z_L Z_L$ scattering processes within the effective chiral Lagrangian approach, including a light Higgs-like scalar as a dynamical field together with the…

High Energy Physics - Phenomenology · Physics 2014-08-27 R. L. Delgado , A. Dobado , M. J. Herrero , J. J. Sanz-Cillero

The effective Lagrangian for \eta' incorporating the effect of the QCD \theta-angle has been developed previously. We revisit this Lagrangian and carry out its canonical quantization with particular attention to the test function spaces of…

High Energy Physics - Phenomenology · Physics 2015-06-04 A. P. Balachandran , T. R. Govindarajan , Amilcar R. de Queiroz

We consider the phenomenological implications of charged scalar extensions of the SM Higgs sector in addition to EFT couplings of this new state to SM matter. We perform a detailed investigation of modifications of loop-induced decays of…

High Energy Physics - Phenomenology · Physics 2021-05-19 Anisha , Upalaparna Banerjee , Joydeep Chakrabortty , Christoph Englert , Michael Spannowsky

We evaluate the two-loop ${\cal O}(\alpha_sG_Fm_t^2)$ correction to the $ZZH$ coupling in the Standard Model by means of a low-energy theorem, assuming that the top quark is much heavier than the Higgs boson. We then construct a…

High Energy Physics - Phenomenology · Physics 2016-09-01 Bernd A. Kniehl , Michael Spira

We investigate the most interesting decay processes involving axions, photons and the lightest pseudoscalar mesons, making use of a chiral effective Lagrangian model with $L=3$ light quark flavors, which also includes the flavor-singlet…

High Energy Physics - Phenomenology · Physics 2020-04-08 Giacomo Landini , Enrico Meggiolaro

We use functional methods to match the Two-Higgs Doublet Model with heavy scalars in the nondecoupling regime to the appropriate nonlinear effective field theory, which takes the form of an electroweak chiral Lagrangian (HEFT). The…

High Energy Physics - Phenomenology · Physics 2024-09-12 G. Buchalla , F. König , Ch. Müller-Salditt , F. Pandler

A $Z_2$ symmetry that extends the weak interaction, $SU(2)_L \rightarrow SU(2)_L \times SU(2)'$, and the Higgs sector, $H(2) \rightarrow H(2,1) + H'(1,2)$, yields a Standard Model quartic coupling that vanishes at scale $v' = <H'>~\gg~<H>$.…

High Energy Physics - Phenomenology · Physics 2018-11-14 Lawrence J. Hall , Keisuke Harigaya

We consider a general effective Lagrangian for couplings of a Higgs boson to the top-quark to dimension-six operators including CP violation effects. Constraints on some of them are derived from the $Z\to b\bar b$ data. We study the process…

High Energy Physics - Phenomenology · Physics 2009-10-31 T. Han , T. Huang , Z. -H. Lin , J. -X. Wang , X. Zhang

We consider the implications of current LHC data on new physics with strongly interacting sector(s). We parametrize the relevant interaction Lagrangian and study the best fit values in light of current data. These are then considered within…

High Energy Physics - Phenomenology · Physics 2015-06-15 Tommi Alanne , Stefano Di Chiara , Kimmo Tuominen

We consider the generalized Yukawa model consisting of two Dirac fermions and two scalar fields. One of the scalars is assumed to be much heavier than the other particles, so it decouples at low energies. Low-energy effective Lagrangian…

High Energy Physics - Phenomenology · Physics 2024-05-28 Mykyta Dmytriiev , Volodymyr Skalozub

We study the indirect effects of New Physics in the Higgs decay into four charged leptons, using an Effective Field Theory (EFT) approach to Higgs interactions. We evaluate the deviations induced by the EFT dimension-six operators in…

High Energy Physics - Phenomenology · Physics 2018-02-14 S. Boselli , C. M. Carloni Calame , G. Montagna , O. Nicrosini , F. Piccinini , A. Shivaji

In these proceedings we explore the use of (non-linear) electroweak chiral Lagrangians for the description of possible beyond the Standard Model strong dynamics in the electroweak sector. Experimentally one observes an approximate…

High Energy Physics - Phenomenology · Physics 2015-06-23 J. J. Sanz-Cillero

In a recent paper we showed that the electroweak chiral Lagrangian at leading order is equivalent to the conventional $\kappa$ formalism used by ATLAS and CMS to test Higgs anomalous couplings. Here we apply this fact to fit the latest…

High Energy Physics - Phenomenology · Physics 2016-05-25 G. Buchalla , O. Cata , A. Celis , C. Krause

In these proceedings we provide a brief summary of the findings of a previous article where we have studied the photon-photon scattering into longitudinal weak bosons within the context of the electroweak chiral Lagrangian with a light…

High Energy Physics - Phenomenology · Physics 2014-11-10 R. L. Delgado , A. Dobado , M. J. Herrero , J. J. Sanz-Cillero

The decays $K^{+} \rightarrow \pi^{+} e^{+} e^{-}$, $K_{S} \rightarrow \pi^{0} e^{+} e^{-}$ and $K_{L} \rightarrow \pi^{0} e^{+} e^{-}$ are reinvestigated within the framework of chiral perturbation theory. The counterterms induced by…

High Energy Physics - Phenomenology · Physics 2009-10-28 S. Fajfer

A coupled-channel effective Lagrangian model respecting unitary and gauge invariance is applied to the combined analysis of the $(\pi,\gamma) N \to K\Sigma$ reactions for the center of mass energies up to 2 GeV. The recent photoproduction…

Nuclear Theory · Physics 2013-11-20 Xu Cao , V. Shklyar , H. Lenske

At the LHC a precise measurement of the Higgs boson mass (if discovered), at the level of 0.1-1%, will be possible through the channel g g --> H --> 4l for a wide range of Higgs mass values. To match such an accuracy, the systematic effects…

High Energy Physics - Phenomenology · Physics 2009-11-11 C. M. Carloni Calame , M. Moretti , G. Montagna , O. Nicrosini , F. Piccinini , A. D. Polosa

We match the electroweak chiral Lagrangian with two singlet scalars to the next-to-minimal composite Higgs model with $ SO(6)/SO(5) $ coset structure and extract the scalar divergences to one loop. Assuming the additional scalar to be…

High Energy Physics - Phenomenology · Physics 2022-04-19 Andreas Lindner , Khoirul Faiq Muzakka