scholarly journals New heavy gauge bosons decaying to pair of electroweak bosons: prospect studies at Run 3 and HL-LHC with ATLAS

2021 ◽  
Vol 29 (1) ◽  
pp. 15-20
Author(s):  
I. A. Serenkova ◽  
A. A. Pankov ◽  
V. A. Bednyakov
Keyword(s):  
Standard Model ◽  
Gauge Boson ◽  
Final States ◽  
Gauge Bosons ◽  
Data Set ◽  
Gauge Sector ◽  
Mixing Parameters ◽  
Upper Limits ◽  
Electroweak Gauge Boson ◽  
Vector Bosons

The expected ATLAS Run 3 data set with time-integrated luminosity of 300 fb-1 and HL-LHC option of the LHC with L = 3000 fb-1 in the diboson channels in semileptonic final states are used to probe a simple benchmark model with an extended gauge sector, proposed by Altarelli et al. This model accommodates new charged W' and neutral Z' vector bosons with modified trilinear Standard Model gauge couplings, decaying into electroweak gauge boson pairs WZ or WW , where W / Z decay semileptonically. We present upper limits on the mixing parameters, W - W' and Z- Z ' , by using the expected Run 3 data and HL-LHC options of the LHC.

scholarly journals Search for Heavy Higgs Bosons in Fermionic Decay Channels with CMS

2018 ◽  
Vol 46 ◽  
pp. 1860058
Author(s):  
Ye Chen
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Confidence Level ◽  
Higgs Bosons ◽  
Final States ◽  
Centre Of Mass ◽  
Decay Channels ◽  
Upper Limits ◽  
The Standard Model ◽  
Cms Detector

Latest results of searches for heavy Higgs bosons in fermionic final states are presented using the CMS detector at the LHC. Results are based on pp collision data collected at centre-of-mass energies of 8 and 13 TeV which have been interpreted according to different extensions of the Standard Model such as MSSM, 2HDM, and NMSSM. These searches look for evidence of other scalar or pseudoscalar bosons, in addition to the observed SM-like 125 GeV Higgs boson, and set 95% confidence level upper limits in fermionic final states and benchmark models explored. The talk reviews briefly the major results obtained by the CMS Collaboration during Run I, and presents the most recent searches performed during Run II.

scholarly journals Standard Model Higgs boson searches at the Tevatron

2014 ◽  
Vol 29 (10) ◽  
pp. 1430009
Author(s):  
Kyle J. Knoepfel
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Cross Section ◽  
Boson Mass ◽  
Standard Model Higgs Boson ◽  
Full Data ◽  
Data Set ◽  
Proton Antiproton ◽  
Vector Bosons ◽  
Best Fit

We give an overview of Standard Model (SM) Higgs boson studies performed at the CDF and D∅ experiments at the Tevatron proton–antiproton collider. Combining the results of many individual analyses, most of which use the full data set available, an excess with a significance of 3.0 standard deviations with respect to the SM hypothesis is observed at a Higgs boson mass of 125 GeV /c2. At that mass, the combined best-fit cross-section is consistent with the SM prediction. Constraints are also placed on the Higgs boson couplings with fermions and electroweak vector bosons and are consistent with the SM predictions within the uncertainties.

scholarly journals Can vanishing mass-on-shell interactions generate a dip at colliders?

2015 ◽  
Vol 30 (20) ◽  
pp. 1550120 ◽  
Author(s):  
Yang Bai ◽  
Wai-Yee Keung
Keyword(s):  
Gauge Boson ◽  
New Physics ◽  
Unstable Particle ◽  
Particle Interactions ◽  
Gauge Bosons ◽  
Complex Mass ◽  
Vector Bosons ◽  
Effective Operators

We categorize new physics signatures that manifest themselves as a “dip” structure at colliders. One potential way to realize a dip is to require interactions to be zero when all particles are mass on-shell, but not if one or more are mass off-shell. For three particle interactions, we have found three interesting cases: one massive gauge boson with two identical scalars; one massless gauge boson with two different scalars; one massive gauge boson with two identical massless gauge bosons. For each case, we identify the relevant effective operators to explore its dip signature at the LHC. Unfortunately, the unstable particle with a vanishing mass-on-shell interaction has a complex mass which is coincident with the complex pole in its propagator. As a result, a contact-like amplitude without a dip is produced. Some interesting collider signatures for “fermion-phobic” vector bosons are also discussed.

GAUGE-BOSON SCATTERING IN A HIDDEN SYMMETRY BREAKING SECTOR AT e+e− COLLIDERS

1996 ◽  
Vol 11 (03) ◽  
pp. 247-255
Author(s):  
M.V. RAMANA
Keyword(s):  
Symmetry Breaking ◽  
Production Rate ◽  
Gauge Boson ◽  
Electroweak Symmetry Breaking ◽  
Final States ◽  
Electroweak Symmetry ◽  
Gauge Bosons ◽  
Hidden Symmetry ◽  
Number Of Particles

We calculate the production rate of gauge-boson pairs at e+e− colliders in a model with a “hidden” electroweak symmetry breaking sector, i.e. one in which there is a large number of particles in the symmetry breaking sector other than the W± and Z0. We show that the background exceeds the two gauge-boson fusion signals of electroweak symmetry breaking. This implies that in order to explore this model we must be prepared to observe final states other than gauge-bosons.

VECTOR BOSON DOMINANCE OF ELECTROWEAK INTERACTIONS

1993 ◽  
Vol 08 (33) ◽  
pp. 3129-3138 ◽  
Author(s):  
YU. F. PIROGOV
Keyword(s):  
Field Theory ◽  
Standard Model ◽  
Vector Boson ◽  
Local Symmetry ◽  
Higgs Bosons ◽  
Quantum Field ◽  
Gauge Bosons ◽  
The Standard Model ◽  
Vector Bosons ◽  
Common Substructure

The linearization of the nonlinear standard model G/H= SU(3) L × U(1)/SU(2) L × U(1) via the hidden local symmetry H loc = SU(2) L × U(1) is considered. Mixing of the light elementary gauge bosons of the standard model with the dynamically generated heavy composite vector bosons is studied under the hypothesis of vector boson dominance. The model is theoretically consistent as quantum field theory and phenomenologically acceptable. It can be used as a guide to study systematically the deviations from the standard model due to a common substructure of leptons, quarks and Higgs bosons.

scholarly journals Gauge Boson Mixing in the 3-3-1 Models with Discrete Symmetries

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
P. V. Dong ◽  
V. T. N. Huyen ◽  
H. N. Long ◽  
H. V. Thuy
Keyword(s):  
Standard Model ◽  
Gauge Boson ◽  
Discrete Symmetries ◽  
Lepton Number ◽  
Neutrino Mixing ◽  
Gauge Bosons ◽  
Neutral Gauge Boson ◽  
Neutral Scalar ◽  
The Standard Model ◽  
Lepton Number Violating

The mixing among gauge bosons in the 3-3-1 models with the discrete symmetries is investigated. To get tribimaximal neutrino mixing, we have to introduce sextets containing neutral scalar components with lepton numberL=1,2. Assignation of VEVs to these fields leads to the mixing of the new gauge bosons and those in the standard model. The mixing in the charged gauge bosons leads to the lepton number violating interactions of theWboson. The same situation happens in the neutral gauge boson sector.

scholarly journals MUSiC: a model-unspecific search for new physics in proton–proton collisions at $$\sqrt{s} = 13\,\text {TeV} $$

2021 ◽  
Vol 81 (7) ◽  
Author(s):  
◽  
A. M. Sirunyan ◽  
A. Tumasyan ◽  
W. Adam ◽  
F. Ambrogi ◽  
...  
Keyword(s):  
Standard Model ◽  
Model Simulation ◽  
Standard Model Prediction ◽  
Proton Collision ◽  
Final States ◽  
Final State ◽  
Data Set ◽  
Proton Proton ◽  
Wide Range ◽  
The Standard Model

AbstractResults of the Model Unspecific Search in CMS (MUSiC), using proton–proton collision data recorded at the LHC at a centre-of-mass energy of 13$$\,\text {TeV}$$ TeV , corresponding to an integrated luminosity of 35.9$$\,\text {fb}^{-1}$$ fb - 1 , are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.

scholarly journals Search for physics beyond the standard model in final states with two or three soft leptons and missing transverse momentum in proton-proton collisions at s=13 TeV

2021 ◽  
Vol 2105 (1) ◽  
pp. 012012
Author(s):  
Ioanna Papavergou ◽  
Emmanouil Vourliotis
Keyword(s):  
Standard Model ◽  
Mass Parameter ◽  
Mass Difference ◽  
Final States ◽  
Top Squark ◽  
Proton Proton ◽  
Missing Transverse Momentum ◽  
Upper Limits ◽  
The Standard Model ◽  
Proton Proton Collisions

Abstract The most recent CMS results from a search for supersymmetry (SUSY) with a compressed mass spectrum in leptonic final states will be presented. The search is targeting signatures with missing transverse momentum and two or three low-momentum (soft) leptons. The dataset used is collected by the CMS experiment during the Run–2 proton-proton collisions at s = 13 TeV at the LHC, and corresponds to an integrated luminosity of up to 137 fb−1. The observed data are found to be in agreement with the Standard Model prediction and exclusion upper limits are set on the SUSY particles production cross section. The results are interpreted in terms of electroweakino and top squark pair production. In both cases, a small mass difference between the produced SUSY particles and the lightest neutralino is considered. A wino-bino and a higgsino simplified models are used for the electroweakino interpretation. Exclusion limits at 95% confidence level are set on x ˜ 2 0 / x ˜ 1 ± masses up to 280 GeV for a mass difference between the x ˜ 2 0 / x ˜ 1 ± and the lightest neutralino of 10 GeV for the wino-bino production. In the higgsino interpretation x ˜ 2 0 / x ˜ 1 ± masses are excluded up to 210 GeV for a mass difference of 7.5 GeV and up to 150 GeV for a mass difference of 3 GeV. The results for the higgsino production are additionally interpreted in terms of a phenomenological minimal SUSY extension of the standard model, excluding the higgsino mass parameter μ up to 180 GeV for bino mass parameter M1 = 800 GeV. Upper limits at 95% confidence level are set on the top squark pair production interpretation, excluding top squark masses up to 530 GeV in the four-body top squark decay model and up to 475 GeV in the chargino-mediated decay model for a mass difference between the top squark and the lightest neutralino of 30 GeV.

UPPER LIMITS ON THE TOP QUARK MASS IN MODELS WITH NEW GAUGE BOSONS

1990 ◽  
Vol 05 (02) ◽  
pp. 115-123 ◽  
Author(s):  
THOMAS G. RIZZO
Keyword(s):  
Top Quark ◽  
Quark Mass ◽  
Top Quark Mass ◽  
Gauge Bosons ◽  
Gauge Sector ◽  
Upper Limit ◽  
Upper Limits ◽  
The Standard Model ◽  
Lower Limits ◽  
Rule Out

The experimental value of the ρ parameter is used to obtain an upper limit on the top-quark mass (mt) in models with extended gauge sectors. This limit is found to be generally stronger than that obtained from similar considerations in the Standard Model (SM). This bound, however, is shown to depend strongly on the particular extension of the usual SM gauge sector under consideration. Improved experimental lower limits on mt can also be used to rule out large regions of the parameter space of extended electroweak models.

scholarly journals ρ PARAMETER IN THE VECTOR CONDENSATE MODEL OF ELECTROWEAK INTERACTIONS

1994 ◽  
Vol 09 (18) ◽  
pp. 1701-1705 ◽  
Author(s):  
G. CYNOLTER ◽  
E. LENDVAI ◽  
G. POCSIK
Keyword(s):  
Gauge Symmetry ◽  
Standard Model ◽  
Vector Boson ◽  
Higgs Doublet ◽  
Electroweak Interactions ◽  
Gauge Bosons ◽  
Momentum Scale ◽  
The Standard Model ◽  
Vector Bosons

In the standard model of electroweak interactions the Higgs doublet is replaced by a doublet of vector bosons and the gauge symmetry is broken dynamically. This generates masses for the gauge bosons and fermions as well as it fixes the interactions in the model. The model has a low momentum scale. In this note we show that the model survives the test of the ρ parameter, and to each momentum scale ρ chooses a possible range of vector boson masses.

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