scholarly journals Lepton flavor violating decay of 125 GeV Higgs boson to μτ channel and excess in tt̄H

2016 ◽  
Vol 31 (30) ◽  
pp. 1650174 ◽  
Author(s):  
Biplob Bhattacherjee ◽  
Sabyasachi Chakraborty ◽  
Swagata Mukherjee
Keyword(s):  
Higgs Boson ◽  
Top Quark ◽  
Center Of Mass ◽  
New Physics ◽  
Final State ◽  
Center Of Mass Energy ◽  
Lepton Flavor ◽  
Higgs Decay ◽  
Energy Formula ◽  
8 Tev

A recent search for the lepton flavor violating (LFV) decays of the Higgs boson, performed by CMS collaboration, reports an interesting deviation from the Standard Model (SM). The search conducted in the channel [Formula: see text] and [Formula: see text] shows an excess of 2.4[Formula: see text] signal events with 19.6 fb[Formula: see text] data at a center-of-mass energy [Formula: see text] = 8 TeV. On the other hand, a search performed by CMS collaboration for the SM Higgs boson produced in association with a top quark pair [Formula: see text] also showed an excess in the same-sign dimuon final state. In this work, we try to find out if these two seemingly uncorrelated excesses are related or not. Our analysis reveals that a LFV Higgs decay [Formula: see text] can partially explain the excess in the same-sign dimuon final state in the [Formula: see text] search, infact brings down the excess well within 2[Formula: see text] error of the SM expectation. Probing such non-standard Higgs boson decay is of interest and might contain hints of new physics at the electroweak scale.

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.

scholarly journals Search for a heavy Higgs boson decaying into two lighter Higgs bosons in the ττbb final state at 13 TeV

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
◽  
A. Tumasyan ◽  
W. Adam ◽  
J. W. Andrejkovic ◽  
T. Bergauer ◽  
...  
Keyword(s):  
Higgs Boson ◽  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
Branching Fractions ◽  
Center Of Mass ◽  
Final State ◽  
Signal Process ◽  
Center Of Mass Energy ◽  
Heavy Higgs Boson

Abstract A search for a heavy Higgs boson H decaying into the observed Higgs boson h with a mass of 125 GeV and another Higgs boson hS is presented. The h and hS bosons are required to decay into a pair of tau leptons and a pair of b quarks, respectively. The search uses a sample of proton-proton collisions collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 137 fb−1. Mass ranges of 240–3000 GeV for mH and 60–2800 GeV for $$ {m}_{{\mathrm{h}}_{\mathrm{S}}} $$ m h S are explored in the search. No signal has been observed. Model independent 95% confidence level upper limits on the product of the production cross section and the branching fractions of the signal process are set with a sensitivity ranging from 125 fb (for mH = 240 GeV) to 2.7 fb (for mH = 1000 GeV). These limits are compared to maximally allowed products of the production cross section and the branching fractions of the signal process in the next-to-minimal supersymmetric extension of the standard model.

scholarly journals Diboson production at LHC and Tevatron

2014 ◽  
Vol 31 ◽  
pp. 1460279 ◽  
Author(s):  
Jian Wang ◽  
Keyword(s):  
Standard Model ◽  
Center Of Mass ◽  
Mass Energy ◽  
Diboson Production ◽  
Center Of Mass Energy ◽  
Triple Gauge Couplings ◽  
Model Predictions ◽  
Energy Formula ◽  
Anomalous Triple Gauge Couplings ◽  
8 Tev

This is a report at the conference Physics In Collision 2013. The experimental results on physics of diboson production are reviewed. The measurements use pp collision at the LHC with center-of-mass energy [Formula: see text] and 8 TeV, and [Formula: see text] collision at the Tevatron with [Formula: see text]. These include measurements of Wγ, Zγ, WW, WZ and ZZ production. The results are compared with Standard Model predictions, and are interpreted in terms of constraints on charged and neutral anomalous triple gauge couplings.

Implementation of the ATLAS-SUSY-2018-32 analysis (sleptons and eletroweakinos with two leptons and missing transverse energy; 139 fb−1)

2020 ◽  
pp. 2141005
Author(s):  
Jack Y. Araz ◽  
Benjamin Fuks
Keyword(s):  
Pair Production ◽  
Transverse Energy ◽  
Center Of Mass ◽  
New Physics ◽  
Missing Transverse Energy ◽  
Missing Energy ◽  
Final State ◽  
Proton Proton ◽  
Weak Boson ◽  
Center Of Mass Energy

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.

Implementation of the CMS-HIG-18-011 analysis in the MadAnalysis 5 framework (exotic Higgs decays via two pseudoscalars with two muons and two b-jets; 35.9 fb−1)

2020 ◽  
pp. 2141003
Author(s):  
Joon-Bin Lee ◽  
Jehyun Lee
Keyword(s):  
Higgs Boson ◽  
Center Of Mass ◽  
Final State ◽  
Proton Proton ◽  
Proton Collisions ◽  
Center Of Mass Energy ◽  
Cms Experiment ◽  
The Standard Model ◽  
Proton Proton Collisions ◽  
Selection Of

We present the implementation in the MadAnalysis 5 framework of the CMS-HIG-18-011 search for exotic decays of the Standard Model Higgs boson, in which the Higgs boson is assumed to decay into a pair of light pseudoscalar [Formula: see text], that then further decay into a di-muon and di-[Formula: see text]-jet final state. This analysis considers proton-proton collisions at a center-of-mass energy of 13 TeV and data collected by the CMS experiment in 2016, with an integrated luminosity of 35.9 fb[Formula: see text]. We present a selection of recast predictions, obtained with MadAnalysis 5 and Delphes 3, that include a few differential distributions, yields, and efficiencies. We show that they agree at a level of a few percent with public CMS results.

scholarly journals Highlights from the Compact Muon Solenoid (CMS) Experiment

Universe ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 28
Author(s):  
Saranya Ghosh ◽  
on behalf of the CMS Collaboration
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Top Quark ◽  
Compact Muon Solenoid ◽  
Production Cross ◽  
Hadron Collider ◽  
Center Of Mass ◽  
Proton Collision ◽  
Center Of Mass Energy ◽  
Cms Experiment

The highlights of the recent activities and physics results leading up to the summer of 2018 from the Compact Muon Solenoid (CMS) experiment at the CERN Large Hadron Collider (LHC) are presented here. The CMS experiment has a very wide-ranging physics program, and only a very limited subset of the physics analyses being performed at CMS are discussed here, consisting of several important results from the analysis of proton-proton collision data at center-of-mass energy of 13 TeV. These include important analyses of Higgs boson physics, with the highlight being the first observation of the t t ¯ H production of the Higgs boson, along with analyses pertaining to precision standard model measurements, top quark physics, with the single top production cross-section measurement, and flavor physics, with the important observation of χ b (3P) states. Additionally, important searches for physics beyond the standard model are also presented.

scholarly journals Probing the Higgs with angular observables at future e+e− colliders

2016 ◽  
Vol 31 (33) ◽  
pp. 1644005 ◽  
Author(s):  
Zhen Liu
Keyword(s):  
Center Of Mass ◽  
Blind Spot ◽  
New Physics ◽  
Effective Field ◽  
Mass Energy ◽  
Center Of Mass Energy ◽  
Physics Potential ◽  
Energy Formula ◽  
Scalar Top ◽  
The Impact

I summarize our recent works on using differential observables to explore the physics potential of future [Formula: see text] colliders in the framework of Higgs effective field theory. This proceeding is based upon Refs. 1 and 2. We study angular observables in the [Formula: see text] channel at future circular [Formula: see text] colliders such as CEPC and FCC-ee. Taking into account the impact of realistic cut acceptance and detector effects, we forecast the precision of six angular asymmetries at CEPC (FCC-ee) with center-of-mass energy [Formula: see text] GeV and 5 (30) ab[Formula: see text] integrated luminosity. We then determine the projected sensitivity to a range of operators relevant for the Higgsstrahlung process in the dimension-6 Higgs EFT. Our results show that angular observables provide complementary sensitivity to rate measurements when constraining various tensor structures arising from new physics. We further find that angular asymmetries provide a novel means of constraining the “blind spot” in indirect limits on supersymmetric scalar top partners. We also discuss the possibility of using [Formula: see text]-fusion at [Formula: see text] machines at different energies to probe new operators.

Search for physics beyond the Standard Model using jet observables

2015 ◽  
Vol 30 (31) ◽  
pp. 1546009 ◽  
Author(s):  
Konstantinos Kousouris
Keyword(s):  
Standard Model ◽  
Center Of Mass ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Final States ◽  
Proton Proton ◽  
Center Of Mass Energy ◽  
The Standard Model ◽  
8 Tev ◽  
Jet Observables

Jet observables have been exploited extensively during the LHC Run 1 to search for physics beyond the Standard Model. In this article, the most recent results from the ATLAS and CMS collaborations are summarized. Data from proton–proton collisions at 7 and 8 TeV center-of-mass energy have been analyzed to study monojet, dijet, and multijet final states, searching for a variety of new physics signals that include colored resonances, contact interactions, extra dimensions, and supersymmetric particles. The exhaustive searches with jets in Run 1 did not reveal any signal, and the results were used to put stringent exclusion limits on the new physics models.

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