scholarly journals Composite Higgs revealed in Higgs pair photo-production at future colliders

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
A. Bharucha ◽  
G. Cacciapaglia ◽  
A. Deandrea ◽  
N. Gaur ◽  
D. Harada ◽  
...  
Keyword(s):  
Standard Model ◽  
Cross Sections ◽  
Higgs Sector ◽  
New Physics ◽  
Destructive Interference ◽  
Composite Higgs ◽  
Electron Positron ◽  
Scalar Resonance ◽  
The Standard Model ◽  
Light Scalar

Abstract The next generation electron-positron colliders are designed for precision studies of the Standard Model and its extensions, in particular in the Higgs sector. We consider the potential for discovery of composite Higgs models in Higgs pair production through photon collisions. This process is loop-generated, thus it provides access to all Higgs couplings and can show new physics effects in polarized and unpolarized cross-sections starting at relatively low collider energies. It is, therefore, relevant for all electron-positron colliders planned or in preparation. Sizeable deviations from the Standard Model predictions are present in a general class of composite Higgs models, as couplings of one or more Higgs bosons to fermions, or fermionic and scalar resonances, modify the destructive interference present in the Standard Model. In particular, large effects are due to the new quartic coupling of the Higgs to tops and to the presence of a light scalar resonance.

scholarly journals W-boson production in the high energy electron-photon collisions

2019 ◽  
pp. 41-50
Author(s):  
Ivan A. Shershan ◽  
Tatiana V. Shishkina
Keyword(s):  
Standard Model ◽  
Cross Sections ◽  
W Boson ◽  
High Energy ◽  
New Physics ◽  
Coupling Constants ◽  
Boson Production ◽  
The Standard Model ◽  
Electron Photon ◽  
W Boson Production

In this paper the analysis of W-boson production process in high-energy electron-photon collisions as a tool to search for deviations from the Standard Model is considered. In particular, a set of extended gauge models, including anomalous multi-boson interactions, are discussed as a promising way for «new physics» study. A numerical analysis of the total cross sections of the processes was carried out. The lowest order radiative corrections in the soft-photon approximation within the Standard Model are taken into account. Calculations beyond the Standard Model was performed, the kinematic features of the cross sections were identified. The restrictions on the anomalous triple gauge boson coupling constants were analyzed and the kinematic areas to the search for their manifestations were obtained during the experiments at the International Linear Collider. The paper shows that the search for «new physics» effects based on electron-photon collisions around the W-boson production peak is the maximal promising. It was also shown that future experiments at high luminosity linear colliders will significantly clarify the constraints on anomalous gauge coupling constants.

scholarly journals BOUND-STATE/ELEMENTARY-PARTICLE DUALITY IN THE HIGGS SECTOR AND THE CASE FOR AN EXCITED "HIGGS" WITHIN THE STANDARD MODEL

2013 ◽  
Vol 28 (28) ◽  
pp. 1350103 ◽  
Author(s):  
AXEL MAAS
Keyword(s):  
Elementary Particle ◽  
Standard Model ◽  
Cross Sections ◽  
Bound States ◽  
Weak Interactions ◽  
Higgs Sector ◽  
Bound State ◽  
Leading Order ◽  
Expectation Value ◽  
The Standard Model

Though being weakly interacting, QED can support bound states. In principle, this can be expected for the weak interactions in the Higgs sector as well. In fact, it has been argued long ago that there should be a duality between bound states and the elementary particles in this sector, at least in leading order in an expansion in the Higgs quantum fluctuations around its expectation value. Whether this remains true beyond the leading order is being investigated using lattice simulations, and support is found. This provides a natural interpretation of peaks in cross-sections as bound states. This would imply that (possibly very broad) resonances of Higgs and W and Z bound states could exist within the Standard Model.

scholarly journals Double elementary Goldstone Higgs boson production in future linear colliders

2018 ◽  
Vol 33 (08) ◽  
pp. 1850038
Author(s):  
Yu-Chen Guo ◽  
Chong-Xing Yue ◽  
Zhi-Cheng Liu
Keyword(s):  
Higgs Boson ◽  
Cross Sections ◽  
New Physics ◽  
Boson Production ◽  
Linear Electron ◽  
Higgs Boson Production ◽  
Electron Positron ◽  
The Standard Model ◽  
Linear Colliders ◽  
The Cross

The Elementary Goldstone Higgs (EGH) model is a perturbative extension of the Standard Model (SM), which identifies the EGH boson as the observed Higgs boson. In this paper, we study pair production of the EGH boson in future linear electron positron colliders. The cross-sections in the TeV region can be changed to about −27%, 163% and −34% for the [Formula: see text], [Formula: see text] and [Formula: see text] processes with respect to the SM predictions, respectively. According to the expected measurement precisions, such correction effects might be observed in future linear colliders. In addition, we compare the cross-sections of double SM-like Higgs boson production with the predictions in other new physics models.

scholarly journals Flavor-dependent radiative corrections in coherent elastic neutrino-nucleus scattering

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Oleksandr Tomalak ◽  
Pedro Machado ◽  
Vishvas Pandey ◽  
Ryan Plestid
Keyword(s):  
Standard Model ◽  
Cross Section ◽  
Cross Sections ◽  
Nuclear Physics ◽  
Heavy Particle ◽  
New Physics ◽  
Effective Field ◽  
Radiative Corrections ◽  
The Standard Model ◽  
Nucleus Scattering

Abstract We calculate coherent elastic neutrino-nucleus scattering cross sections on spin-0 nuclei (e.g. 40Ar and 28Si) at energies below 100 MeV within the Standard Model and account for all effects of permille size. We provide a complete error budget including uncertainties at nuclear, nucleon, hadronic, and quark levels separately as well as perturbative error. Our calculation starts from the four-fermion effective field theory to explicitly separate heavy-particle mediated corrections (which are absorbed by Wilson coefficients) from light-particle contributions. Electrons and muons running in loops introduce a non- trivial dependence on the momentum transfer due to their relatively light masses. These same loops, and those mediated by tau leptons, break the flavor universality because of mass-dependent electromagnetic radiative corrections. Nuclear physics uncertainties significantly cancel in flavor asymmetries resulting in subpercent relative errors. We find that for low neutrino energies, the cross section can be predicted with a relative precision that is competitive with neutrino-electron scattering. We highlight potentially useful applications of such a precise cross section prediction ranging from precision tests of the Standard Model, to searches for new physics and to the monitoring of nuclear reactors.

scholarly journals CP violating effects in 210Fr and prospects for new physics beyond the Standard Model

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Nanako Shitara ◽  
Nodoka Yamanaka ◽  
Bijaya Kumar Sahoo ◽  
Toshio Watanabe ◽  
Bhanu Pratap Das
Keyword(s):  
Standard Model ◽  
Higgs Sector ◽  
Higgs Doublet ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Internal Electric Field ◽  
Many Body ◽  
The Standard Model ◽  
The Many ◽  
Two Higgs Doublet Model

Abstract We report theoretical results of the electric dipole moment (EDM) of 210Fr which arises from the interaction of the EDM of an electron with the internal electric field in an atom and the scalar-pseudoscalar electron-nucleus interaction; the two dominant sources of CP violation in this atom. Employing the relativistic coupled-cluster theory, we evaluate the enhancement factors for these two CP violating interactions to an accuracy of about 3% and analyze the contributions of the many-body effects. These two quantities in combination with the projected sensitivity of the 210Fr EDM experiment provide constraints on new physics beyond the Standard Model. Particularly, we demonstrate that their precise values are necessary to account for the effect of the bottom quark in models in which the Higgs sector is augmented by nonstandard Yukawa interactions such as the two-Higgs doublet model.

Bremsstrahlung Calculations of Single Gauge-Boson Production on Linear Colliders in Context of "New Physics" Searching

2021 ◽  
Vol 24 (4) ◽  
pp. 317-325
Author(s):  
I. A. Shershan ◽  
T. V. Shishkina
Keyword(s):  
Standard Model ◽  
Gauge Boson ◽  
Cross Sections ◽  
Dimensional Regularization ◽  
High Energy ◽  
New Physics ◽  
Boson Production ◽  
Leading Order ◽  
The Standard Model ◽  
Electron Photon

Differential and total cross sections of single gauge boson production in high energy electron-photon collisions obtained within the Standard Model in leading order and next-to-leading order are presented. Soft photon bremsstrahlung as well as hard photon bremsstrahlung parts were considered using the dimensional regularization procedure. Special features of receiving the hard bremsstrahlung convergent contribution are discussed. The corresponding anomalous gauge boson couplings were studied in the effective Lagrangian approach. Best conditions for registration of effects beyond the Standard Model are determined.

scholarly journals Tau-neutrino as a probe of nonstandard interactions via charged Higgs and W′ contribution

2014 ◽  
Vol 29 (07) ◽  
pp. 1450040
Author(s):  
Ahmed Rashed
Keyword(s):  
Standard Model ◽  
Cross Sections ◽  
New Physics ◽  
Mixing Angles ◽  
Tau Neutrino ◽  
Standard Model Cross Section ◽  
The Standard Model ◽  
Charged Higgs ◽  
Reactor Mixing ◽  
The Impact

We discuss the impact of the presence of a charged Higgs boson and a W′ gauge boson on the tau-neutrino nucleon scattering ντ+N→τ-+X and [Formula: see text]. We show the effect of the new physics on the quasielastic, Δ-resonance and deep inelastic scattering. The measurements for the atmospheric and reactor mixing angles θ23 and θ13 in the appearance analyses νμ →ντ and [Formula: see text] are based on the Standard Model cross-section of the above processes. The measured mixing angles are changed when considering the new physics contributions to those reactions, assuming the Standard Model cross-sections. We include form factor effects in the new physics calculations and find the deviations of the mixing angles can be significant and can depend on the energy of the neutrino.

scholarly journals Searching for dark sectors in multi lepton final state in e+e− collisions

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Paolo Ciafaloni ◽  
Gabriele Martelli ◽  
Mauro Raggi
Keyword(s):  
Standard Model ◽  
New Physics ◽  
Dark Sector ◽  
Fixed Target ◽  
Final State ◽  
Relative Contribution ◽  
Electron Positron ◽  
The Standard Model ◽  
Experimental Problem ◽  
Positron Collisions

Abstract Electron positron collisions are a very promising environment to search for new physics, and in particular for dark sector related observables. The most challenging experimental problem in detecting dark sector candidates is the very high associated Standard Model background. For this reason it is important to identify observables that are, at the same time, minimally suppressed in the dark sector and highly suppressed in the Standard Model. One example is the e+e− → 3(e+e−) process that can be mediated either by the production and subsequent decay of dark Higgs (h′), e+e− → A′h′ → 6e [1] or produced by the Standards Model process e+e− → 3(e+e−). In the following letter we study the relative contribution to observed e+e− → 3(e+e−) total cross section, coming from the h′ mediated and from the Standard Model processes in the contest of fixed target and low energy collider experiments, with particular attention to the PADME experiment at the INFN Laboratori Nazionali di Frascati.

scholarly journals Survival of new physics: Anomaly-free neutral gauge boson at the LHC

2014 ◽  
Vol 29 (08) ◽  
pp. 1450046
Author(s):  
Ying Zhang ◽  
Qing Wang
Keyword(s):  
Standard Model ◽  
Direct Detection ◽  
Decay Channel ◽  
Hadron Collider ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Effective Lagrangian ◽  
Charge Assignment ◽  
Electron Positron ◽  
The Standard Model

An anomaly-free U(1)′ effective Lagrangian as a benchmark of new physics beyond the standard model is proposed to survey the maximal parameter space constrained by the precise electroweak measurements at the Large Electron-Positron Collider (LEP) and direct detection of the dilepton decay channel at [Formula: see text] at the Large Hadron Collider (LHC). By the global fit of the effective couplings of the Z boson to the Standard Model fermions, parameters Δ11, Δ21 and g′′Δ31 related to mixings and r related to the U(1)′ charge assignment are bounded. The allowed areas are plotted not only in the r–g′′ plane, but also in the mZ′–g′′ plane. They show that a sub-TeV Z′ is still permissible as long as the coupling g′′ is of order ~0.01. The results hint at possible new physics beyond the standard model. A prediction of the possible signal for the dilepton decay channel at [Formula: see text] at LHC is also provided.

scholarly journals A NEW MECHANISM FOR NEUTRINO MASS

1999 ◽  
Vol 14 (14) ◽  
pp. 913-917 ◽  
Author(s):  
P. P. DIVAKARAN ◽  
G. RAJASEKARAN
Keyword(s):  
Standard Model ◽  
Neutrino Mass ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Composite Higgs ◽  
The Standard Model

A mechanism for generating massive but naturally light Dirac neutrinos is proposed. It involves composite Higgs within the standard model as well as some new interaction beyond the standard model. According to this scenario, a neutrino mass of 0.1 eV or higher, signals new physics at energies of 10–100 TeV or lower.

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