scholarly journals Vector boson fusion at multi-TeV muon colliders

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Antonio Costantini ◽  
Federico De Lillo ◽  
Fabio Maltoni ◽  
Luca Mantani ◽  
Olivier Mattelaer ◽  
...  
Keyword(s):  
Cross Sections ◽  
Vector Boson ◽  
High Energy ◽  
New Physics ◽  
Vector Boson Fusion ◽  
Weak Boson ◽  
Wide Range ◽  
Lepton Colliders ◽  
Muon Colliders ◽  
New Phenomena

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.

scholarly journals Measuring Higgs boson self-couplings with 2 → 3 VBS processes

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Junmou Chen ◽  
Chih-Ting Lu ◽  
Yongcheng Wu
Keyword(s):  
Higgs Boson ◽  
Cross Sections ◽  
Effective Field Theory ◽  
Vector Boson ◽  
Effective Field ◽  
Low Energy ◽  
Final States ◽  
Lepton Colliders ◽  
Vector Boson Scattering ◽  
Muon Colliders

Abstract We study the measurement of Higgs boson self-couplings through 2 → 3 vector boson scattering (VBS) processes in the framework of Standard Model effective field theory (SMEFT) at both proton and lepton colliders. The SMEFT contribution to the amplitude of the 2 → 3 VBS processes, taking WLWL → WLWLh and WLWL → hhh as examples, exhibits enhancement with the energy $$ \frac{{\mathcal{A}}^{\mathrm{BSM}}}{{\mathcal{A}}^{\mathrm{SM}}}\sim \frac{E^2}{\Lambda^2} $$ A BSM A SM ~ E 2 Λ 2 , which indicates the sensitivity of these processes to the related dimension-six operators in SMEFT. Simulation of the full processes at both hadron and lepton colliders with a variety of collision energies are performed to estimate the allowed region on c6 and $$ {c}_{\Phi_1} $$ c Φ 1 . Especially we find that, with the help of exclusively choosing longitudinal polarizations in the final states and suitable pT cuts, WWh process is as important as the more widely studied triple Higgs production (hhh) in the measurement of Higgs self-couplings. Our analysis indicates that these processes can play important roles in the measurement of Higgs self-couplings at future 100 TeV pp colliders and muon colliders. However, their cross sections are generally tiny at low energy machines, which makes them much more challenging to explore.

scholarly journals Two paths towards precision at a very high energy lepton collider

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Dario Buttazzo ◽  
Roberto Franceschini ◽  
Andrea Wulzer
Keyword(s):  
Cross Sections ◽  
Vector Boson ◽  
Center Of Mass ◽  
Percent Level ◽  
High Energy ◽  
New Physics ◽  
Higgs Production ◽  
Diboson Production ◽  
Very High Energy ◽  
Very High

Abstract We illustrate the potential of a very high energy lepton collider (from 10 to 30 TeV center of mass energy) to explore new physics indirectly in the vector boson fusion double Higgs production process and in direct diboson production at high energy. Double Higgs production is found to be sensitive to the anomalous Higgs trilinear coupling at the percent level, and to the Higgs compositeness ξ parameter at the per mille or sub-per mille level thanks to the measurement of the cross-section in the di-Higgs high invariant mass tail. High energy diboson (and tri-boson) production is sensitive to Higgs-lepton contact interaction operators at a scale of several tens or hundred TeV, corresponding to a reach on the Higgs compositeness scale well above the one of any other future collider project currently under discussion. This result follows from the unique capability of the very high energy lepton collider to measure Electroweak cross-sections at 10 TeV energy or more, where the effect of new physics at even higher energy is amplified. The general lesson is that the standard path towards precision physics, based on measurements of high-statistics processes such as single and double Higgs production, is accompanied at the very high energy lepton collider by a second strategy based on measurements at the highest available energy.

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
Keyword(s):  
Pair Production ◽  
Vector Boson ◽  
New Physics ◽  
Higgs Bosons ◽  
Vector Boson Fusion ◽  
Final State ◽  
Proton Proton ◽  
Effective Lagrangian ◽  
Discovery Potential ◽  
New Interactions

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.

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.

High(est) energy lepton colliders

2021 ◽  
pp. 2142016
Author(s):  
Roberto Franceschini
Keyword(s):  
Standard Model ◽  
Center Of Mass ◽  
High Energy ◽  
New Physics ◽  
Mass Energy ◽  
Center Of Mass Energy ◽  
Lepton Colliders ◽  
The Standard Model

We discuss the physics opportunities and challenges presented by high energy lepton colliders in the range of center-of-mass energy between few and several tens of TeV. The focus is on the progress attainable on the study of weak and Higgs interactions in connection with new physics scenarios motivated by the shortcomings of the Standard Model.

scholarly journals tt̄H Coupling Measurement with the ATLAS Detector at the LHC

2018 ◽  
Vol 182 ◽  
pp. 02052
Author(s):  
Asma Hadef
Keyword(s):  
Higgs Boson ◽  
Cross Sections ◽  
Top Quark ◽  
High Energy Physics ◽  
Center Of Mass ◽  
High Energy ◽  
New Physics ◽  
Decay Modes ◽  
Center Of Mass Energy ◽  
Higgs Decay

The Higgs boson was discovered on the 4th of July 2012 with a mass around 125 GeV by ATLAS and CMS experiments at LHC. Determining the Higgs properties (production and decay modes, couplings,...) is an important part of the high-energy physics programme in this decade. A search for the Higgs boson production in association with a top quark pair (tt̄H) at ATLAS [1] is summarized in this paper at an unexplored center-of-mass energy of 13 TeV, which could allow a first direct measurement of the top quark Yukawa coupling and could reveal new physics. The tt̄H analysis in ATLAS is divided into 3 channels according to the Higgs decay modes: H → Hadrons, H → Leptons and H → Photons. The best-fit value of the ratio of observed and Standard Model cross sections of tt̄H production process, using 2015-2016 data and combining all tt̄H final states, is 1:8±0:7, corresponds to 2:8σ (1:8σ) observed (expected) significance.

QCD JETS AT HERA I.: O(αs) RADIATIVE CORRECTIONS TO ELECTROWEAK CROSS SECTIONS AND JET RATES

1989 ◽  
Vol 04 (07) ◽  
pp. 1781-1825 ◽  
Author(s):  
JÜRGEN G. KÖRNER ◽  
ERWIN MIRKES ◽  
GERHARD A. SCHULER
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Neutral Current ◽  
High Energy ◽  
Coupling Constant ◽  
Bjorken Scaling ◽  
Born Cross Section ◽  
Wide Range ◽  
Lepton Polarization ◽  
Jet Cross Sections

We present the complete O(αs) corrections to the electroweak cross sections of both neutral current and charged current deep inelastic e±p scattering including lepton polarization effects. Changes in the cross section due to the inclusion of next-to-leading-log (NLL) effects are parametrized by K factors, which are defined as the ratio of the NLL O(αs) cross sections and the Born cross section. Using the standard redefinition scheme of the parton densities, we find that the K factors deviate substantially from unity for small values of the Bjorken-Scaling variable x. We also elaborate on problems that arise when defining jet cross sections in ep scattering and present numerical results for the O(αs) 3-jet and 2-jet rates. We observe that the Q2-dependence of the 3-jet rate is dominated by the running strong coupling constant αs(Q2) allowing for its determination over a wide range in Q2 at high energy ep colliders.

scholarly journals Neutralinos in vector boson fusion at high energy colliders

2015 ◽  
Vol 91 (11) ◽  
Author(s):  
Asher Berlin ◽  
Tongyan Lin ◽  
Matthew Low ◽  
Lian-Tao Wang
Keyword(s):  
Vector Boson ◽  
High Energy ◽  
Vector Boson Fusion

scholarly journals NEW PHYSICS DISCOVERY POTENTIAL IN FUTURE EXPERIMENTS

1998 ◽  
Vol 13 (40) ◽  
pp. 3235-3249 ◽  
Author(s):  
S. I. BITYUKOV ◽  
N. V. KRASNIKOV
Keyword(s):  
Cross Sections ◽  
High Energy Physics ◽  
High Energy ◽  
New Physics ◽  
Physics Simulation ◽  
Discovery Potential ◽  
Proper Definition ◽  
Definition Of ◽  
Physics Experiments ◽  
Energy Physics

We propose a method to estimate the probability of new physics discovery in future high energy physics experiments. Physics simulation gives both the average numbers <Nb> of background and <Ns> of signal events. We find that the proper definition of the significance for <Nb>, <Ns> ≫ 1 is [Formula: see text] in comparison with often used significances: [Formula: see text] and [Formula: see text]. We propose a method of taking into account the systematical errors related to nonexact knowledge of background and signal cross-sections. An account of such systematics is essential in the search for supersymmetry at LHC. We also propose a method for estimating exclusion limits on new physics in future experiments.

Sign in / Sign up

Export Citation Format

Share Document