scholarly journals Search for a heavy resonance decaying into a Z boson and a vector boson in the ν ν ¯ q q ¯ $$ \nu \overline{\nu}\mathrm{q}\overline{\mathrm{q}} $$ final state

2018 ◽  
Vol 2018 (7) ◽  
Author(s):  
A. M. Sirunyan ◽  
◽  
A. Tumasyan ◽  
W. Adam ◽  
F. Ambrogi ◽  
...  
Keyword(s):  
Z Boson ◽  
Vector Boson ◽  
Final State

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 STANDARD MODEL HIGGS COMBINED RESULT FROM CDF

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 825-827
Author(s):  
◽  
JOÃO GUIMARÃES DA COSTA
Keyword(s):  
Standard Model ◽  
Cross Section ◽  
Z Boson ◽  
Decay Channel ◽  
Vector Boson ◽  
Associated Production ◽  
The Standard Model ◽  
The Individual ◽  
Cross Section Limit

The Tevatron is expected to be most sensitive to the Standard Model Higgs in its associated production with a W or Z boson. The Collider Detector at Fermilab (CDF) has performed individual searches for such production in each decay channel of the vector boson, assuming that the Higgs decays to [Formula: see text]. These searches use data collected by CDF during the 1992-95 run. The individual results are reviewed, and a combined cross section limit is presented.

scholarly journals Observation of ZZ production via Vector Boson Scattering in ATLAS

2021 ◽  
Vol 2105 (1) ◽  
pp. 012013
Author(s):  
Ioannis Maznas
Keyword(s):  
Cross Sections ◽  
Vector Boson ◽  
Statistical Significance ◽  
Signal Strength ◽  
Atlas Detector ◽  
Pp Collisions ◽  
Final State ◽  
Measurement Results ◽  
Vector Boson Scattering

Abstract This document presents measurement results of the ZZ production via Vector Boson Scattering interactions in 139fb −1 of data recorded by the ATLAS detector from pp collisions at s = 13 TeV during LHC Run-II (2015-2018). In this study, 127 candidate events with a fully leptonic final state (ℓℓℓℓjj) have been observed and another 82 events for ℓℓvvjj final state, with a contribution of the purely electroweak ZZjj process estimated to be 20.6 ± 2.5 and 12.3 ± 0.7 events respectively. The measured cross sections were found to be 1.27 ± 0.14fb (1.22 ± 0.35fb) for ℓℓℓℓjj (ℓℓvvjj) in their respective fiducial regions. Using multivariant methods, the EW production of ZZjj events (combining the ℓℓℓℓjj and ℓℓvvjj channels) was measured to have a signal strength of 1.35± 0.34, which leads to a rejection of the no-electroweak hypothesis with a statistical significance of 5.5σ.

scholarly journals Search for a light pseudoscalar Higgs boson in the boosted μμττ final state in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
A. M. Sirunyan ◽  
◽  
A. Tumasyan ◽  
W. Adam ◽  
F. Ambrogi ◽  
...  
Keyword(s):  
Higgs Boson ◽  
Branching Fraction ◽  
Vector Boson ◽  
Mass Difference ◽  
Standard Technique ◽  
Gluon Fusion ◽  
Large Mass ◽  
Proton Collision ◽  
Final State ◽  
Proton Proton

Abstract A search for a light pseudoscalar Higgs boson (a) decaying from the 125 GeV (or a heavier) scalar Higgs boson (H) is performed using the 2016 LHC proton-proton collision data at $$ \sqrt{s} $$ s = 13 TeV, corresponding to an integrated luminosity of 35.9 fb−1, collected by the CMS experiment. The analysis considers gluon fusion and vector boson fusion production of the H, followed by the decay H → aa → μμττ, and considers pseudoscalar masses in the range 3.6 < ma< 21 GeV. Because of the large mass difference between the H and the a bosons and the small masses of the a boson decay products, both the μμ and the ττ pairs have high Lorentz boost and are collimated. The ττ reconstruction efficiency is increased by modifying the standard technique for hadronic τ lepton decay reconstruction to account for a nearby muon. No significant signal is observed. Model-independent limits are set at 95% confidence level, as a function of ma, on the branching fraction (ℬ) for H → aa → μμττ, down to 1.5 (2.0) × 10−4 for mH = 125 (300) GeV. Model-dependent limits on ℬ(H → aa) are set within the context of two Higgs doublets plus singlet models, with the most stringent results obtained for Type-III models. These results extend current LHC searches for heavier a bosons that decay to resolved lepton pairs and provide the first such bounds for an H boson with a mass above 125 GeV.

SEARCHES FOR EXTRA DIMENSIONS AND Z′ BOSONS AT DØ

2005 ◽  
Vol 20 (15) ◽  
pp. 3277-3283 ◽  
Author(s):  
◽  
RYAN J. HOOPER
Keyword(s):  
Z Boson ◽  
Extra Dimensions ◽  
Large Extra Dimensions ◽  
Z Bosons ◽  
Planck Scale ◽  
Final States ◽  
Mass Limit ◽  
Theoretical Frameworks ◽  
Final State ◽  
Dielectron Channel

We present results on the searches for Extra Dimensions and Z′ Bosons conducted at the Tevatron's DØ Detector using dielectron, diphoton, and dimuon final states. The theoretical frameworks of Large Extra Dimensions (LED), Randall-Sundrum Extra Dimensions (RS), TeV-1 Extra Dimensions, and Z′ bosons are explored in the dielectron and diphoton channels, while LED and Z′ bosons are also searched for in the dimuon final state. In the absence of signals we find lower 95% confidence level (CL) limits on the mass of a SM-like Z′ boson of 780 GeV and 680 GeV in the dielectron and dimuon channels, respectively. Furthermore, we find a lower 95% CL limit of 1.12 TeV on the TeV-1 compactification scale ( M C) in the dielectron channel. In the diEM channel and LED framework we set a lower 95% CL limit of 1.43 TeV (GRW) on the fundamental Planck scale ( M S). Using a dimuon final state we find a lower 95% CL limit of 1.1 TeV (GRW) on M S. We also find a lower 95% CL mass limit of 785 GeV on a RS graviton decaying into a dielectron or diphoton final state.

scholarly journals The Z boson in the framed standard model

2018 ◽  
Vol 33 (32) ◽  
pp. 1850190 ◽  
Author(s):  
José Bordes ◽  
Hong-Mo Chan ◽  
Sheung Tsun Tsou
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Z Boson ◽  
Unknown Parameter ◽  
Vector Boson ◽  
Great Accuracy ◽  
Experimental Accuracy ◽  
Hidden Sector ◽  
The Standard Model ◽  
Mixing Patterns

The framed standard model (FSM), constructed initially for explaining the existence of three fermion generations and the hierarchical mass and mixing patterns of quarks and leptons,[Formula: see text] suggests also a “hidden sector” of particles3 including some dark matter candidates. It predicts in addition a new vector boson [Formula: see text], with mass of order TeV, which mixes with the [Formula: see text] and [Formula: see text] of the standard model yielding deviations from the standard mixing scheme, all calculable in terms of a single unknown parameter [Formula: see text]. Given that standard mixing has been tested already to great accuracy by experiment, this could lead to contradictions, but it is shown here that for the three crucial and testable cases so far studied (i) [Formula: see text], (ii) [Formula: see text], (iii) [Formula: see text]), the deviations are all within the present stringent experimental bounds provided [Formula: see text] TeV, but should soon be detectable if experimental accuracy improves. This comes about because of some subtle cancellations, which might have a deeper reason that is not yet understood. By virtue of mixing, [Formula: see text] can be produced at the LHC and appear as a [Formula: see text] anomaly. If found, it will be of interest not only for its own sake but serve also as a window on to the “hidden sector” into which it will mostly decay, with dark matter candidates as most likely products.

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