scholarly journals Highly boosted Higgs bosons and unitarity in vector-boson fusion at future hadron colliders

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Wolfgang Kilian ◽  
Sichun Sun ◽  
Qi-Shu Yan ◽  
Xiaoran Zhao ◽  
Zhijie Zhao

Abstract We study the observability of new interactions which modify Higgs-pair production via vector-boson fusion processes at the LHC and at future proton-proton colliders. In an effective-Lagrangian approach, we explore in particular the effect of the operator $$ {h}^2{W}_{\mu \nu}^a{W}^{a,\mu \nu} $$ h 2 W μν a W a , μν , which describes the interaction of the Higgs boson with transverse vector-boson polarization modes. By tagging highly boosted Higgs bosons in the final state, we determine projected bounds for the coefficient of this operator at the LHC and at a future 27 TeV or 100 TeV collider. Taking into account unitarity constraints, we estimate the new-physics discovery potential of Higgs pair production in this channel.

2020 ◽  
pp. 2141005
Author(s):  
Jack Y. Araz ◽  
Benjamin Fuks

We present the implementation in MadAnalysis 5 of the ATLAS-SUSY-2018-32 search for new physics and document the validation of this re-implementation. This analysis targets, with 139 fb[Formula: see text] of proton–proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector, the electroweak pair production of supersymmetric charginos and sleptons when they further decay into a final state comprising a pair of leptons and missing energy. The validation of our work is based on three [Formula: see text]-parity conserving supersymmetric benchmark setups that feature, respectively, chargino pair-production followed by decays into leptons via an intermediate weak boson, chargino pair-production followed by chargino cascade decays into leptons through a slepton mediator, and slepton pair-production followed by slepton direct decays into leptons.


2021 ◽  
Vol 81 (8) ◽  
Author(s):  
A. M. Sirunyan ◽  
A. Tumasyan ◽  
W. Adam ◽  
J. W. Andrejkovic ◽  
T. Bergauer ◽  
...  

AbstractA search for charged Higgs bosons produced in vector boson fusion processes and decaying into vector bosons, using proton–proton collisions at $$\sqrt{s}=13\,{\text {TeV}} $$ s = 13 TeV at the LHC, is reported. The data sample corresponds to an integrated luminosity of 137$$\,{\text {fb}}^{-1}$$ fb - 1 collected with the CMS detector. Events are selected by requiring two or three electrons or muons, moderate missing transverse momentum, and two jets with a large rapidity separation and a large dijet mass. No excess of events with respect to the standard model background predictions is observed. Model independent upper limits at 95% confidence level are reported on the product of the cross section and branching fraction for vector boson fusion production of charged Higgs bosons as a function of mass, from 200 to 3000$$\,{\text {GeV}}$$ GeV . The results are interpreted in the context of the Georgi–Machacek model.


2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Antonio Costantini ◽  
Federico De Lillo ◽  
Fabio Maltoni ◽  
Luca Mantani ◽  
Olivier Mattelaer ◽  
...  

Abstract High-energy lepton colliders with a centre-of-mass energy in the multi-TeV range are currently considered among the most challenging and far-reaching future accelerator projects. Studies performed so far have mostly focused on the reach for new phenomena in lepton-antilepton annihilation channels. In this work we observe that starting from collider energies of a few TeV, electroweak (EW) vector boson fusion/scattering (VBF) at lepton colliders becomes the dominant production mode for all Standard Model processes relevant to studying the EW sector. In many cases we find that this also holds for new physics. We quantify the size and the growth of VBF cross sections with collider energy for a number of SM and new physics processes. By considering luminosity scenarios achievable at a muon collider, we conclude that such a machine would effectively be a “high-luminosity weak boson collider,” and subsequently offer a wide range of opportunities to precisely measure EW and Higgs couplings as well as discover new particles.


2018 ◽  
Vol 98 (11) ◽  
Author(s):  
Frédéric A. Dreyer ◽  
Alexander Karlberg

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