scholarly journals Enhancement of the double Higgs production via leptoquarks at the LHC

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Leandro Da Rold ◽  
Manuel Epele ◽  
Anibal Medina ◽  
Nicolás I. Mileo ◽  
Alejandro Szynkman

Abstract Measurements of single Higgs production and its decays are in good agreement with the Standard Model. There is still room for large modifications in double Higgs production at LHC, though these effects may be correlated with large corrections to other observables, in particular single Higgs production. In this work we address the issue of enhancing double Higgs production in the presence of scalar leptoquarks while satisfying all experimental constraints. We show at leading order that including more than one species of leptoquarks, large cubic interactions with the Higgs can lead to sizable enhancement of di-Higgs production cross section at LHC, while at the same time keeping other Higgs observables and precision measurements under control. For masses above 800 GeV these corrections are in general below 30%, whereas in a viable scenario in which one of the leptoquarks can be light, specifically in the mass range 400 − 600 GeV, we show that it is possible to roughly double the SM cross section for di-Higgs production, implying that possible first hints of it may be probed at the high luminosity LHC at $$ \mathcal{L} $$ L ∼ 2 ab−1.

2006 ◽  
Vol 21 (26) ◽  
pp. 1999-2008 ◽  
Author(s):  
IRINEL CAPRINI ◽  
MARINA ROTARU

The search for heavy charged leptons predicted by generalizations of the standard model is an objective of the experiments at future colliders, in particular at the LHC. We compute the Next-to-Leading Order (NLO) QCD virtual corrections to the production of pairs of heavy charged leptons by gluon fusion. The radiative corrections increase the production rate by about 30% and reduce its dependence on the renormalization and the factorization scales. The effect of a fourth family of quarks on the production cross-section is briefly discussed.


2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Claude Duhr ◽  
Falko Dulat ◽  
Bernhard Mistlberger

Abstract We present the production cross section for a lepton-neutrino pair at the Large Hadron Collider computed at next-to-next-to-next-to-leading order (N3LO) in QCD perturbation theory. We compute the partonic coefficient functions of a virtual W± boson at this order. We then use these analytic functions to study the progression of the perturbative series in different observables. In particular, we investigate the impact of the newly obtained corrections on the inclusive production cross section of W± bosons, as well as on the ratios of the production cross sections for W+, W− and/or a virtual photon. Finally, we present N3LO predictions for the charge asymmetry at the LHC.


2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Alexander Lind ◽  
Andrea Banfi

AbstractWe present H1jet, a fast code that computes the total cross section and differential distribution in the transverse momentum of a colour singlet. In its current version, the program implements only leading-order $$2\rightarrow 1$$ 2 → 1 and $$2\rightarrow 2$$ 2 → 2 processes, but could be extended to higher orders. We discuss the processes implemented in H1jet, give detailed instructions on how to implement new processes, and perform comparisons to existing codes. This tool, mainly designed for theorists, can be fruitfully used to assess deviations of selected new physics models from the Standard Model behaviour, as well as to quickly obtain distributions of relevance for Standard Model phenomenology.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Hasan Ogul ◽  
Kamuran Dilsiz

Prediction of Z→l+l- production cross section (where l±=e±,μ±) in proton-proton collisions at s=14 TeV is estimated up to next-to-next-to-leading order (NNLO) in perturbative QCD including next-to-leading order (NLO) electroweak (EW) corrections. The total inclusive Z boson production cross section times leptonic branching ratio, within the invariant mass window 66<mll<116 GeV, is predicted using NNLO HERAPDF2.0 at NNLO QCD and NLO EW as σZTot=2111.69-26.92+26.31 (PDF) ±11 (αs) ±17 (scale) -30.98+57.41 (parameterization and model). Theoretical prediction of the fiducial cross section is further computed with the latest modern PDF models (CT14, MMHT2014, NNPDF3.0, HERAPDF2.0, and ABM12) at NNLO for QCD and NLO for EW. The central values of the predictions are based on DYNNLO 1.5 program and the uncertainties are extracted using FEWZ 3.1 program. In addition, the cross section is also calculated as functions of μR and μF scales. The choice of μR and μF for scale variation uncertainty is further discussed in detail.


2019 ◽  
Vol 34 (38) ◽  
pp. 2050065
Author(s):  
Gabriel Facini ◽  
Kyrylo Merkotan ◽  
Matthias Schott ◽  
Alexander Sydorenko

Fiducial production cross-section measurements of Standard Model processes, in principle, provide constraints on new physics scenarios via a comparison of the predicted Standard Model cross-section and the observed cross-section. This approach received significant attention in recent years, both from direct constraints on specific models and the interpretation of measurements in the view of effective field theories. A generic problem in the reinterpretation of Standard Model measurements is the corrections application of to data to account for detector effects. These corrections inherently assume the Standard Model to be valid, thus implying a model bias of the final result. In this work, we study the size of this bias by studying several new physics models and fiducial phase–space regions. The studies are based on fast detector simulations of a generic multi-purpose detector at the Large Hadron Collider. We conclude that the model bias in the associated reinterpretations is negligible only in specific cases, however, typically on the same level as systematic uncertainties of the available measurements.


1998 ◽  
Vol 13 (17) ◽  
pp. 2883-2930 ◽  
Author(s):  
GIORGIO CHIARELLI

In this review I summarize the results obtained by CDF on top physics. After the discovery of the top quark, the efforts were concentrated on obtaining precision measurements of the observables. A description of the algorithms developed and used to isolate top in various samples is given, together with the discussion of background and selection strategies followed. The measurements of top mass and [Formula: see text] production cross section are discussed in detail and studies related to top decays and kinematics of [Formula: see text] events are presented.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
A. Gutiérrez-Rodríguez ◽  
M. A. Hernández-Ruíz

We study the prospects of theB-Lmodel with an additionalZ′boson to be a Higgs boson factory at high-energy and high-luminosity linear electron positron colliders, such as the ILC and CLIC, through the Higgs-strahlung processe+e-→(Z,Z′)→Zh, including both the resonant and the nonresonant effects. We evaluate the total cross section ofZhand we calculate the total number of events for integrated luminosities of 500–2000 fb−1and center of mass energies between 500 and 3000 GeV. We find that the total number of expectedZhevents can reach 106, which is a very optimistic scenario and it would be possible to perform precision measurements for bothZ′and Higgs boson in future high-energye+e-colliders experiments.


2011 ◽  
Vol 20 (05) ◽  
pp. 1243-1270 ◽  
Author(s):  
A. I. AHMADOV ◽  
R. M. BURJALIYEV

In this paper, we investigate the next-to-leading order contribution of the higher-twist Feynman diagrams to the large-pT inclusive pion production cross-section in proton–proton collisions and present the general formulae for the higher-twist differential cross-sections in the case of the running coupling and frozen coupling approaches. We compared the resummed next-to-leading order higher-twist cross-sections with the ones obtained in the framework of the frozen coupling approach and leading-twist cross-section. The structure of infrared renormalon singularities of the higher-twist subprocess cross-section and its resummed expression (the Borel sum) are found. It is shown that the resummed result depends on the choice of the meson wave functions used in the calculations. We discuss the phenomenological consequences of possible higher-twist contributions to the meson production in proton–proton collisions in next-to-leading order at RHIC.


Sign in / Sign up

Export Citation Format

Share Document