Study of (W/Z)H Production and Higgs Boson Couplings Using H2!WW* Decays with the ATLAS Detector

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Total Pages : 65 pages
Book Rating : 4.:/5 (925 download)

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Book Synopsis Study of (W/Z)H Production and Higgs Boson Couplings Using H2!WW* Decays with the ATLAS Detector by :

Download or read book Study of (W/Z)H Production and Higgs Boson Couplings Using H2!WW* Decays with the ATLAS Detector written by and published by . This book was released on 2015 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for Higgs boson production in association with a W or Z boson, in the H2!W W* decay channel, is performed with a data sample collected with the ATLAS detector at the LHC in proton-proton collisions at centre-of-mass energies [arrow]"=7 TeV and 8 TeV, corresponding to integrated luminosities of 4.5 fb-1 and 20.3 fb-1, respectively. The WH production mode is studied in two-lepton and three-lepton final states, while two- lepton and four-lepton final states are used to search for the ZH production mode. The observed significance, for the combined WH and ZH production, is 2.5 standard deviations while a significance of 0.9 standard deviations is expected in the Standard Model Higgs boson hypothesis. The ratio of the combined WH and ZH signal yield to the Standard Model expectation, [mu]VH, is found to be [mu]VH = 3.0-1.1+1.3 (stat.)-0.7+1.0 (sys.) for the Higgs boson mass of 125.36 GeV. WH and ZH production modes are also combined with the gluon fusion and vector boson fusion production modes studied in the H 2!W W* 2!l[nu]l[nu] decay channel, resulting in an overall observed significance of 6.5 standard deviations and [mu]ggF+VBF+VH=1.16-0.15+0.16 (stat.) -0.15+0.18 (sys.). The results are interpreted in terms of scaling factors of the Higgs boson couplings to vector bosons ([kappa]V) and fermions ([kappa]F); the combined results are.

Study of (W/Z)H Production and Higgs Boson Couplings Using H2!W W * Decays with the ATLAS Detector

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Book Synopsis Study of (W/Z)H Production and Higgs Boson Couplings Using H2!W W * Decays with the ATLAS Detector by :

Download or read book Study of (W/Z)H Production and Higgs Boson Couplings Using H2!W W * Decays with the ATLAS Detector written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for Higgs boson production in association with a W or Z boson, in the H2!W W * decay channel, is performed with a data sample collected with the ATLAS detector at the LHC in proton-proton collisions at centre-of-mass energies \(\sqrt{s}=7 \) TeV and 8 TeV, corresponding to integrated luminosities of 4.5 fb-1 and 20.3 fb-1, respectively. The WH production mode is studied in two-lepton and three-lepton final states, while two- lepton and four-lepton final states are used to search for the ZH production mode. The observed significance, for the combined W H and ZH production, is 2.5 standard deviations while a significance of 0.9 standard deviations is expected in the Standard Model Higgs boson hypothesis. The ratio of the combined W H and ZH signal yield to the Standard Model expectation, [mu]V H, is found to be [mu] V H = 3.0-1.1+1.3 (stat.)-0.7 +1.0 (sys.) for the Higgs boson mass of 125.36 GeV. The W H and ZH production modes are also combined with the gluon fusion and vector boson fusion production modes studied in the H 2!W W * 2!l[nu]l[nu] decay channel, resulting in an overall observed significance of 6.5 standard deviations and [mu]ggF + VBF + VH = 1.16-0.15+0.16 (stat.) -0.15+0.18 (sys.). The results are interpreted in terms of scaling factors of the Higgs boson couplings to vector bosons ([kappa]V) and fermions ([kappa]F); the combined results are.

Discovery and Measurement of the Higgs Boson in the WW Decay Channel

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Publisher : Springer
ISBN 13 : 3319199897
Total Pages : 175 pages
Book Rating : 4.3/5 (191 download)

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Book Synopsis Discovery and Measurement of the Higgs Boson in the WW Decay Channel by : David Hall

Download or read book Discovery and Measurement of the Higgs Boson in the WW Decay Channel written by David Hall and published by Springer. This book was released on 2015-06-15 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the stand-alone discovery and measurement of the Higgs boson in its decays to two W bosons using the Run-I ATLAS dataset. This is the most precise measurement of gluon-fusion Higgs boson production and is among the most significant results attained at the LHC. The thesis provides an exceptionally clear exposition on a complicated analysis performed by a large team of researchers. Aspects of the analysis performed by the author are explained in detail; these include new methods for evaluating uncertainties on the jet binning used in the analysis and for estimating the background due to associated production of a W boson and an off-shell photon. The thesis also describes a measurement of the WW cross section, an essential background to Higgs boson production. The primary motivation of the LHC was to prove or disprove the existence of the Higgs boson. In 2012, CERN announced this discovery and the resultant ATLAS publication contained three decay channels: gg, ZZ, and WW.

Constraints on New Phenomena Via Higgs Boson Couplings and Invisible Decays with the ATLAS Detector

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ISBN 13 :
Total Pages : 52 pages
Book Rating : 4.:/5 (94 download)

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Book Synopsis Constraints on New Phenomena Via Higgs Boson Couplings and Invisible Decays with the ATLAS Detector by :

Download or read book Constraints on New Phenomena Via Higgs Boson Couplings and Invisible Decays with the ATLAS Detector written by and published by . This book was released on 2015 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ATLAS experiment at the LHC has measured the Higgs boson couplings and mass, and searched for invisible Higgs boson decays, using multiple production and decay channels with up to 4.7 fb-1 of pp collision data at √s=7 TeV and 20.3 fb-1 at √s=8 TeV. In the current study, the measured production and decay rates of the observed Higgs boson in the [gamma][gamma], ZZ, W W , Z[gamma], bb, [tau] [tau] , and [mu][mu] decay channels, along with results from the associated production of a Higgs boson with a top-quark pair, are used to probe the scaling of the couplings with mass. The limits are set on parameters in extensions of the Standard Model including a composite Higgs boson, an additional electroweak singlet, and two-Higgs-doublet models. Together with the measured mass of the scalar Higgs boson in the [gamma][gamma] and ZZ decay modes, a lower limit is set on the pseudoscalar Higgs boson mass of mA > 370 GeV in the "hMSSM" simplified Minimal Supersymmetric Standard Model. Results from direct searches for heavy Higgs bosons are also interpreted in the hMSSM. Finally, direct searches for invisible Higgs boson decays in the vector-boson fusion and associated production of a Higgs boson with W/Z (Z → ll, W/Z → jj) modes are statistically combined to set an upper limit on the Higgs boson invisible branching ratio of 0.25. As a result, the use of the measured visible decay rates in a more general coupling fit improves the upper limit to 0.23, constraining a Higgs portal model of dark matter.

Search for the Higgs Boson in the Vector Boson Fusion Channel at the ATLAS Detector

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Publisher : Springer
ISBN 13 : 3319135996
Total Pages : 114 pages
Book Rating : 4.3/5 (191 download)

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Book Synopsis Search for the Higgs Boson in the Vector Boson Fusion Channel at the ATLAS Detector by : Eric Ouellette

Download or read book Search for the Higgs Boson in the Vector Boson Fusion Channel at the ATLAS Detector written by Eric Ouellette and published by Springer. This book was released on 2015-01-20 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Thesis describes the first measurement of, and constraints on, Higgs boson production in the vector boson fusion mode, where the Higgs decays to b quarks (the most common decay channel), at the LHC. The vector boson fusion mode, in which the Higgs is produced simultaneously with a pair of quark jets, provides an unparalleled opportunity to study the detailed properties of the Higgs, including the possibility of parity and CP violation, as well as its couplings and mass. It thus opens up this new field of study for precision investigation as the LHC increases in energy and intensity, leading the way to this new and exciting arena of precision Higgs research.

ATLAS Measurements of the Higgs Boson Coupling to the Top Quark in the Higgs to Diphoton Decay Channel

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Publisher : Springer
ISBN 13 : 9783030863708
Total Pages : 0 pages
Book Rating : 4.8/5 (637 download)

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Book Synopsis ATLAS Measurements of the Higgs Boson Coupling to the Top Quark in the Higgs to Diphoton Decay Channel by : Jennet Elizabeth Dickinson

Download or read book ATLAS Measurements of the Higgs Boson Coupling to the Top Quark in the Higgs to Diphoton Decay Channel written by Jennet Elizabeth Dickinson and published by Springer. This book was released on 2022-11-18 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: During Run 2 of the Large Hadron Collider, the ATLAS experiment recorded proton-proton collision events at 13 TeV, the highest energy ever achieved in a collider. Analysis of this dataset has provided new opportunities for precision measurements of the Higgs boson, including its interaction with the top quark. The Higgs-top coupling can be directly probed through the production of a Higgs boson in association with a top-antitop quark pair (ttH). The Higgs to diphoton decay channel is among the most sensitive for ttH measurements due to the excellent diphoton mass resolution of the ATLAS detector and the clean signature of this decay. Event selection criteria were developed using novel Machine Learning techniques to target ttH events, yielding a precise measurement of the ttH cross section in the diphoton channel and a 6.3 $\sigma$ observation of the ttH process in combination with other decay channels, as well as stringent limits on CP violation in the Higgs-top coupling.

Measurements of ZH and WH Production in the H → Bb Decay Channel in Pp Collisions at 13 TeV with the ATLAS Detector

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (124 download)

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Book Synopsis Measurements of ZH and WH Production in the H → Bb Decay Channel in Pp Collisions at 13 TeV with the ATLAS Detector by : ATLAS Collaboration CERN

Download or read book Measurements of ZH and WH Production in the H → Bb Decay Channel in Pp Collisions at 13 TeV with the ATLAS Detector written by ATLAS Collaboration CERN and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Measurements are presented of the Standard Model Higgs boson decaying into a bb ̄ pair and produced in association with a W or Z boson decaying into leptons, using proton-proton collision data collected between 2015 and 2018 by the ATLAS detector. The measurements use data delivered by the Large Hadron Collider at a centre-of-mass energy of s√=13 TeV, corresponding to an integrated luminosity of 139 fb−1. The production of a Higgs boson in association with a W or Z boson is established, with observed (expected) significances of 4.0 (4.1) and 5.3 (5.1) standard deviations, respectively. Cross-sections of associated production of a Higgs boson decaying into bottom quark pairs with an electroweak gauge boson, W or Z, decaying into leptons are measured as a function of the gauge boson transverse momentum in kinematic fiducial volumes. The cross-section measurements are all consistent with the Standard Model expectations, and the total uncertainties vary from 30% in the high gauge boson transverse momentum regions to 85% in the low regions

Measurements of WH and ZH Production in the H->bb Decay Channel in Pp Collisions at 13TeV with the ATLAS Detector

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (135 download)

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Book Synopsis Measurements of WH and ZH Production in the H->bb Decay Channel in Pp Collisions at 13TeV with the ATLAS Detector by : ATLAS Collaboration CERN

Download or read book Measurements of WH and ZH Production in the H->bb Decay Channel in Pp Collisions at 13TeV with the ATLAS Detector written by ATLAS Collaboration CERN and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Measurements of the Standard Model Higgs boson decaying into a bb ̄ pair and produced in association with a W or Z boson decaying into leptons, using proton-proton collision data collected between 2015 and 2018 by the ATLAS detector, are presented. The measurements use collisions produced by the Large Hadron Collider at a centre-of-mass energy of s√=13TeV, corresponding to an integrated luminosity of 139fb−1. The production of a Higgs boson in association with a W or Z boson is established with observed (expected) significances of 4.0 (4.1) and 5.3 (5.1) standard deviations, respectively. Cross-sections of associated production of a Higgs boson decaying into bottom quark pairs with an electroweak gauge boson, W or Z, decaying into leptons are measured as a function of the gauge boson transverse momentum in kinematic fiducial volumes. The cross-section measurements are all consistent with the Standard Model expectations, and the total uncertainties vary from 30% in the high gauge boson transverse momentum regions to 85% in the low regions. Limits are subsequently set on the parameters of an effective Lagrangian sensitive to modifications of the WH and ZH processes as well as the Higgs boson decay into bb ̄

Measurements of Higgs Boson Production and Couplings in Diboson Final States with the ATLAS Detector at the LHC.

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (951 download)

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Book Synopsis Measurements of Higgs Boson Production and Couplings in Diboson Final States with the ATLAS Detector at the LHC. by :

Download or read book Measurements of Higgs Boson Production and Couplings in Diboson Final States with the ATLAS Detector at the LHC. written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H→[gamma][gamma], H→ZZ{sup *}→4l and H→WW{sup *}→l[nu]l[nu]. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of {radical s}=7 TeV and {radical s}=8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson.

Measurement of Higgs Boson Production Via Vector Boson Fusion in Decays Into W Bosons with the ATLAS Detector

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ISBN 13 :
Total Pages : 214 pages
Book Rating : 4.:/5 (888 download)

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Book Synopsis Measurement of Higgs Boson Production Via Vector Boson Fusion in Decays Into W Bosons with the ATLAS Detector by : Johanna Bronner

Download or read book Measurement of Higgs Boson Production Via Vector Boson Fusion in Decays Into W Bosons with the ATLAS Detector written by Johanna Bronner and published by . This book was released on 2014 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Search for the Standard Model Higgs Boson Production and Decay to W Boson Pairs Using the Lepton + Met + Jets Channel Using 4.7 Fb−1 of Data Recorded by the ATLAS Detector at √s

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ISBN 13 :
Total Pages : 294 pages
Book Rating : 4.:/5 (847 download)

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Book Synopsis Search for the Standard Model Higgs Boson Production and Decay to W Boson Pairs Using the Lepton + Met + Jets Channel Using 4.7 Fb−1 of Data Recorded by the ATLAS Detector at √s by : Dilip Kumar Jana

Download or read book Search for the Standard Model Higgs Boson Production and Decay to W Boson Pairs Using the Lepton + Met + Jets Channel Using 4.7 Fb−1 of Data Recorded by the ATLAS Detector at √s written by Dilip Kumar Jana and published by . This book was released on 2013 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Higgs from Top to Bottom

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ISBN 13 : 9789402813029
Total Pages : 283 pages
Book Rating : 4.8/5 (13 download)

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Book Synopsis Higgs from Top to Bottom by : Tim Michael Heinz Wolf

Download or read book Higgs from Top to Bottom written by Tim Michael Heinz Wolf and published by . This book was released on 2018 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the Standard Model (SM) of particle physics, it is expected that the Higgs boson as a scalar spin-0 particle gives mass to all other elementary particles. In addition, the coupling to the top quark, as the heaviest elementary particle, is expected to be of order unity. Proton--proton collision data at a center of mass energy of 13 TeV collected by the ATLAS experiment during Run 2 of the Large Hadron Collider is used to study the interaction between the Higgs boson and the top quark. Data of up to 79.8 fb−1 in various Higgs boson decay modes is analyzed to study Higgs boson production in association with a pair of top quarks (ttH) and probe the SM expectation. This thesis focuses on Higgs decays to bottom quarks and faces the challenges inherent to this decay mode such as limited amount of Monte Carlo statistics and limited understanding of the background modeling. In this thesis, the collected data is used to establish the Higgs boson-top quark coupling by combining analyses targeting different Higgs boson decay modes, employing cutting edge statistical methods. The extracted cross-section ratio with respect to the SM prediction of the ttH process is measured to be 1.32 (+0.28 -0.26) in agreement with the SM expectation. This constitutes a discovery with a significance of 5.8 standard deviations and establishes the coupling between the Higgs boson and the top quark.

Measurement of the Higgs Boson Production and Couplings in the Four-lepton Decay Channel with the ATLAS Detector

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Publisher :
ISBN 13 :
Total Pages : 200 pages
Book Rating : 4.:/5 (949 download)

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Book Synopsis Measurement of the Higgs Boson Production and Couplings in the Four-lepton Decay Channel with the ATLAS Detector by : Stefano Zambito

Download or read book Measurement of the Higgs Boson Production and Couplings in the Four-lepton Decay Channel with the ATLAS Detector written by Stefano Zambito and published by . This book was released on 2015 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Searches for Associated Higgs Boson Production with Top Quark Pair and Higgs Pair Production in Multi Lepton Final States with the ATLAS Detector

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (122 download)

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Book Synopsis Searches for Associated Higgs Boson Production with Top Quark Pair and Higgs Pair Production in Multi Lepton Final States with the ATLAS Detector by : Merve Nazlim Agaras

Download or read book Searches for Associated Higgs Boson Production with Top Quark Pair and Higgs Pair Production in Multi Lepton Final States with the ATLAS Detector written by Merve Nazlim Agaras and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the discovery of the Higgs boson at a mass around 125 GeV by both ATLAS and CMS collaborations in July 2012, it became crucial to measure its properties, such as its couplings to other particles, and search for any deviations from the Standard Model (SM) predictions. The top quark Yukawa coupling is close to unity and the strongest in the fermionic sector. Therefore, this coupling plays a crucial role in the theory. Determination of the associated production of The Higgs boson production with a pair of top quarks (ttH) offers a tree-level access to measuring this coupling. The analysis of ttH production at ATLAS experiment exploits several Higgs decay channel, together with different top quark decay modes. In this thesis, the study of the ttH (H → Multi lepton) process is presented in the topology where the Higgs decays to WW,ZZ or tautau, using a dataset corresponding to an integrated luminosity of 79.8fb^-1 at √s = 13 TeV, collected with the ATLAS detector between 2015-2017. Improved knowledge on the background modelling and the complex fit model is used with many degrees of freedoms. Particularly different fit setups are presented in order to understand the modelling of the major irreducible background, ttW. Furthermore, a search for the SM Higgs boson pair production in the multi lepton final states is presented. The search uses 139fb^-1 of proton-proton collisions data at a centre-of-mass energy of 13 TeV provided by the Large Hadron Collider (LHC) and recorded by the ATLAS experiment in 2015 and 2018. The first studies in two lepton same-sign channel is performed for lepton working point optimisation and estimation of background contributions. Template fit method is applied to estimated the reducible backgrounds and preliminary expected upper limit is calculated.

Measurements of the Higgs Boson Inclusive and Differential Fiducial Cross-sections in the Diphoton Decay Channel with Pp Collisions at [square Root]s

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (137 download)

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Book Synopsis Measurements of the Higgs Boson Inclusive and Differential Fiducial Cross-sections in the Diphoton Decay Channel with Pp Collisions at [square Root]s by : [Study Group] ATLAS Collaboration CERN

Download or read book Measurements of the Higgs Boson Inclusive and Differential Fiducial Cross-sections in the Diphoton Decay Channel with Pp Collisions at [square Root]s written by [Study Group] ATLAS Collaboration CERN and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: A measurement of inclusive and differential fiducial cross-sections for the production of the Higgs boson decaying into two photons is performed using 139 fb−1 of proton-proton collision data recorded at s√ = 13 TeV by the ATLAS experiment at the Large Hadron Collider. The inclusive cross-section times branching ratio, in a fiducial region closely matching the experimental selection, is measured to be 67 ± 6 fb, which is in agreement with the state-of-the-art Standard Model prediction of 64 ± 4 fb. Extrapolating this result to the full phase space and correcting for the branching ratio, the total cross-section for Higgs boson production is estimated to be 58 ± 6 pb. In addition, the cross-sections in four fiducial regions sensitive to various Higgs boson production modes and differential cross-sections as a function of either one or two of several observables are measured. All the measurements are found to be in agreement with the Standard Model predictions. The measured transverse momentum distribution of the Higgs boson is used as an indirect probe of the Yukawa coupling of the Higgs boson to the bottom and charm quarks. In addition, five differential cross-section measurements are used to constrain anomalous Higgs boson couplings to vector bosons in the Standard Model effective field theory framework

Observation of H→bb Decays and VH Production with the ATLAS Detector, Anglais

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (11 download)

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Book Synopsis Observation of H→bb Decays and VH Production with the ATLAS Detector, Anglais by : Yanhui Ma

Download or read book Observation of H→bb Decays and VH Production with the ATLAS Detector, Anglais written by Yanhui Ma and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for the Standard Model Higgs boson produced in association with a W or Z boson, and decaying to a bb pair has been performed with ATLAS detector. The data were collected in proton-proton collisions during Run 2 of the Large Hadron Collider at a centre-of-mass energy of 13 TeV, and correspond to an integrated luminosity of 79.8 fb−1. Three channels containing zero, one and two charged leptons (electrons or muons) have been considered to target each of the leptonic decays of the W or Z boson, Z->vv, W->lv et Z->ll, referred to as as the 0-lepton, 1-lepton and 2-lepton channels, respectively. For a Higgs boson mass of 125 GeV, an excess of events over the expected background from other Standard Model processes is found with an observed significance of 4.9 standard deviations, compared to an expectation of 4.3 standard deviations. The ratio of the measured signal events to the Standard Model expectation equal 1.16 +0.27/-0.25 = 1.16 +/-0.16(stat) +0.21/-0.19(syst). The result is also combined with the other results from the searches for the Higgs boson in the bb 18 decay mode in Run 1 and Run 2, the combination yields an observed (expected) significance of 5.4 (5.5) 20 standard deviations, and therefore provides a direct observation of the Higgs boson decay into a bb pair. In addition, a combination of Run 2 results searching for the Higgs boson produced in association with a W or Z boson yields an observed (expected) significance of 5.3 (4.8) standard deviations, and therefore provides a direct observation of Higgs boson being produced in association with a W or Z boson.

Measurement of the Brout-Englert-Higgs Boson Couplings in Its Diphoton Decay Channel with the ATLAS Detector at the LHC

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ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (892 download)

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Book Synopsis Measurement of the Brout-Englert-Higgs Boson Couplings in Its Diphoton Decay Channel with the ATLAS Detector at the LHC by : Estelle Scifo

Download or read book Measurement of the Brout-Englert-Higgs Boson Couplings in Its Diphoton Decay Channel with the ATLAS Detector at the LHC written by Estelle Scifo and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: After the Higgs boson discovery in the first LHC data, the focus is now on its properties measurement. Among these properties, its couplings are of particular importance since any deviation from the expected value can be an indication of new physics, beyond the Standard Model. This thesis is oriented towards the Higgs couplings measurements with the ATLAS experiment, using the diphoton decay channel. Selected diphoton events are classified into different categories to disentangle the five Higgs production modes by tagging the objects produced in association with the Higgs boson: two jets for the VBF production mode, lepton and missing transverse energy for the higgsstrahlung (WH and ZH), b-jets for ttH, the remaining events being mostly produced via the dominant production mode ggH. The impact of the Higgs pT modelling in the ggH production mode is also investigated. Theoretical developments provide predictions of the pT shape at NNLO+NNLL accuracy, including top and bottom mass effects in the loop up to NLO+NLL, implemented in the HRes program. A reweighting technique to take into account these latest theoretical improvements is derived, taking into consideration the correlation with the number of jets. Its impact on the final measurement is estimated to be of the order of a few percent. The final couplings results, measured at the Higgs mass obtained by the combination of the H->gamma gamma and H->ZZ*->4l channels in ATLAS (mH = 125.4 +/- 0.4 GeV) do not show any statistically significant deviation from the Standard Model. The observed signal strength mu = sigma^{obs} / sigma^{exp} is found to be: mu = 1.17^{+0.28}_{-0.25} = 1.17 +/- 0.23(stat) ^{+0.10}_{-0.08}(syst) ^{+0.12}_{-0.08}(theory). The ratio of the observed number of events in each production mode to the expected ones are measured at: mu_ggH = 1.32 +/- 0.32(stat.) ^{+0.13}_{-0.09}(syst.) ^{+0.19}_{-0.11}(theory) ; mu_VBF = 0.8 +/- 0.7(stat.) ^{+0.2}_{-0.1}(syst.) ^{+0.2}_{-0.3}(theory) ; mu_WH = 1.0 +/- 1.5(stat.) ^{+0.3}_{-0.1}(syst.) ^{+0.2}_{-0.1}(theory) ; mu_ZH = 0.1 ^{+3.6}_{-0.1}(stat.) ^{+0.7}_{-0.0}(syst.) ^{+0.1}_{-0.0}(theory) ; mu_ttH = 1.6 ^{+2.6}_{-1.8}(stat.) ^{+0.6}_{-0.4}(syst.} ^{+0.5}_{-0.2}(theory).