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Related papers: Unitarity in Multi-Higgs Production

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Unruh-DeWitt Hamiltonian couples a scalar field with a two-level atom serving as a particle detector model. Two such detectors held by different observers following general trajectories can be used to study entanglement behavior in quantum…

High Energy Physics - Theory · Physics 2018-02-08 Kamil Bradler

A spontaneously broken SU(2) theory is the simplest generalization of the Abelian Higgs model, containing three equally massive vector bosons and a single Higgs scalar. A strictly diagrammatic proof is presented of the tree-level unitarity…

High Energy Physics - Phenomenology · Physics 2020-10-29 Jochem Kip , Ronald Kleiss

We demonstrate enhanced di-Higgs production at the LHC in the presence of modifications of the effective couplings of Higgs to gluons from new, light, colored scalars. While our results apply to an arbitrary set of colored scalars, we…

High Energy Physics - Phenomenology · Physics 2013-05-30 Graham D. Kribs , Adam Martin

We study the cosmological perturbations created during the New Higgs inflationary phase. In the New Higgs Inflation, the Higgs boson is kinetically coupled to the Einstein tensor and only three perturbative degrees of freedom, a scalar and…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Cristiano Germani , Alex Kehagias

We study the three-particle and four-particle scattering amplitudes for an arbitrary, finite number of massive scalars, spinors and vectors by employing the on-shell massive spinor formalism. We consider the most general three-particle…

High Energy Physics - Theory · Physics 2022-12-02 Da Liu , Zhewei Yin

The commutators of the Poincar\'e group generators will be unchanged in form if a unitary transformation relates the free generators to the generators of an interacting relativistic theory. We test the concept of unitary transformations of…

Quantum Physics · Physics 2024-06-19 Scott E. Hoffmann

We study the effects of two-body Higgs boson scattering by exchanging unpsrticles. The unparticle contribution can change the standard model prediction for two-body Higgs boson scattering partial wave amplitude significantly leading to…

High Energy Physics - Phenomenology · Physics 2008-11-26 Xiao-Gang He , Chung-Cheng Wen

An attempt is made to present the influence of the scalar unparticle on some scattering processes in the Randall - Sundum model. The contribution of the scalar unparticle on the production of Higgs - radion at high energy colliders is…

High Energy Physics - Phenomenology · Physics 2018-09-21 D. V. Soa , B. T. H. Giang

In many new physics scenarios, the particle content of the Standard Model is extended and the Higgs couplings are modified, sometimes without affecting single Higgs production. We analyse two models with additional quarks. In these models,…

High Energy Physics - Phenomenology · Physics 2014-10-20 Sally Dawson , Elisabetta Furlan , Ian Lewis

We consider single-diffractive (SD) Higgs production in association with heavy flavour in proton-proton collisions at the LHC. The main focus of our study is a reliable estimate of SD/inclusive ratio, not a precision computation of the…

High Energy Physics - Phenomenology · Physics 2015-11-18 Roman Pasechnik , Boris Kopeliovich , Irina Potashnikova

We study inflationary models based on a non-minimal coupling of a singlet scalar to gravity, focussing on the preheating dynamics and the unitarity issues in this regime. If the scalar does not have significant couplings to other fields,…

High Energy Physics - Phenomenology · Physics 2023-08-16 Oleg Lebedev , Yann Mambrini , Jong-Hyun Yoon

Symmetry-breaking phase transitions are central to our understanding of states of matter. When a continuous symmetry is spontaneously broken, new excitations appear that are tied to fluctuations of the order parameter. In superconductors…

We present a fully analytic calculation of the leading-order one-loop amplitude for triple Higgs production via gluon fusion, $gg \to HHH$, retaining full dependence on the mass of the heavy quark circulating in the loop. This amplitude…

High Energy Physics - Phenomenology · Physics 2025-07-28 John M. Campbell , Giuseppe De Laurentis , R. Keith Ellis

We compute the probability of producing $n$ particles from few colliding particles in the unbroken $(3+1)$-dimensional $\lambda\phi^4$ theory. To this end we numerically implement semiclassical method of singular solutions which works at…

High Energy Physics - Phenomenology · Physics 2023-02-27 S. V. Demidov , B. R. Farkhtdinov , D. G. Levkov

If the di-photon excess at 750 GeV hinted by the 2015 data at the LHC is explained in terms of a scalar resonance participating in the breaking of the electro-weak symmetry, this resonance must be accompanied by other scalar states for…

High Energy Physics - Phenomenology · Physics 2016-08-10 Marco Fabbrichesi , Alfredo Urbano

These lectures are a pedagogical introduction to the application of perturbative unitarity to Higgs physics within and beyond the Standard Model (SM). I begin with a review of how perturbative unitarity arises from quantum mechanical…

High Energy Physics - Phenomenology · Physics 2025-04-02 Heather E. Logan

Following the proposal of arXiv:1312.6673, multi-particle scattering amplitudes are represented as conserved higher-spin charges. The advantage of such reformulation is that multi-particle amplitudes acquire the form of an integral of a…

High Energy Physics - Theory · Physics 2020-01-08 Y. O. Goncharov , M. A. Vasiliev

In single field inflationary models, preheating refers to the phase that immediately follows inflation, but precedes the epoch of reheating. During this phase, the inflaton typically oscillates at the bottom of its potential and gradually…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-25 Dhiraj Kumar Hazra , Jerome Martin , L. Sriramkumar

A generalization of Brillouin-Wigner perturbation theory is applied numerically to the Wigner Band Random Matrix model. The perturbation theory tells that a perturbed energy eigenstate can be divided into a perturbative part and a…

Condensed Matter · Physics 2007-05-23 Wen-ge Wang

I present an extension to arbitrary N of a previously proposed field theoretic model, in which unitary amplitudes for $1->8$ processes were obtained. The Born amplitude in this extension has the behavior $A(1->N)^{tree}\ =\ g^{N-1}\ N!$…

High Energy Physics - Phenomenology · Physics 2009-10-22 Haim Goldberg