Download or read book Measurement of Higgs Boson Production Cross Sections in the Diphoton Channel written by Ahmed Tarek Abouelfadl Mohamed and published by Springer Nature. This book was released on 2020-11-12 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the measurement of the Higgs boson cross section in the diphoton decay channel. The measurement relies on proton-proton collision data at a center-of-mass energy √s = 13 TeV recorded by the ATLAS experiment at the Large Hadron Collider (LHC). The collected data correspond to the full Run-2 dataset with an integrated luminosity of 139 fb-1. The measured cross sections are used to constrain anomalous Higgs boson interactions in the Effective Field Theory (EFT) framework. The results presented in this thesis represent a reduction by a factor 2 of the different photon and jet energy scale and resolution systematic uncertainties with respect to the previous ATLAS publication. The thesis details the calibration of electron and photon energies in ATLAS, in particular the measurement of the presampler energy scale and the estimation of its systematic uncertainty. This calibration was used to perform a measurement of the Higgs boson mass in the H → γγ and H → 4l channels using the 36 fb−1 dataset.
Download or read book Measurement of Differential Cross Sections for Higgs Boson Production in the Diphoton Decay Channel in Pp Collisions at sqrt s written by and published by . This book was released on 2016 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, we presented a measurement of differential cross sections for the Higgs boson (H) production in pp collisions at √s = 8 TeV. The analysis exploits the H →?? decay in data corresponding to an integrated luminosity of 19.7 fb-1 collected by the CMS experiment at the LHC. The cross section is measured as a function of the kinematic properties of the diphoton system and of the associated jets. Results corrected for detector effects are compared with predictions at next-to-leading order and nextto-next-to-leading order in perturbative quantum chromodynamics, as well as with predictions beyond the standard model. Furthermore, for isolated photons with pseudorapidities.
Download or read book Higgs Boson Cross Section Measurements in the Diphoton Decay Channel in Proton proton Collisions at s written by Ivan Konstantinovich Pogrebnyak and published by . This book was released on 2021 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents ATLAS measurements of the total and differential fiducial cross sections for the process of the Higgs boson production and subsequent decay to two photons. The analyzed dataset of proton-proton collisions at √s = 13 TeV has an integrated luminosity of 139 ifb and was collected during the Run 2 of the Large Hadron Collider in 2015–2018. The cross sections were measured in a fiducial phase space closely matching the experimental selection, and compared to the Standard Model predictions from the state-of-the-art calculations. The differential cross sections were measured with respect to an array of observables, allowing us to probe the kinematics, jet activity, and spin and CP properties of the Higgs boson interactions. The data were analyzed iteratively, with yearly results from partial datasets presented at conferences and in publications. The inclusive fiducial cross section obtained from the analysis of the full Run 2 dataset is 65.2 ± 4.5 (stat.) ± 5.6 (exp.) ± 0.3 (theory) fb, which is in excellent agreement with the SM prediction of 63.5 ± 3.3 fb. The results provide the state-of-the-art experimental measurements of the Higgs boson production cross sections, and extend our confidence in the SM in the Higgs sector and QCD, as well as in the computational techniques used to obtain theoretical predictions.
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
Download or read book Measurements of Fiducial Differential Cross Sectionsfor Higgs Boson Production in the Diphoton Decay Channel at s written by Marco Filipuzzi and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Higgs Boson Production in the Diphoton Decay Channel with CMS at the LHC written by Martina Machet and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Discovery of the Higgs Boson with the Diphoton Decay Channel and First Differential Cross section Measurements with ATLAS written by and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In July 2012, a Higgs boson was discovered by both the ATLAS and CMS experiments. This thesis presents the most recent version of the H ->[gamma][gamma] analysis that was used in the discovery. Since the discovery, focus has shifted to measure the properties of the Higgs boson. The analysis presented here is the analysis of the Higgs couplings, where events are divided into twelve categories defined to isolate the various production processes. Specific focus is given to the vector boson fusion (VBF) process where the Higgs boson is produced in association with two foward/backward jets. Due to its small theory errors, the VBF process can allow for very precise measurements of the Higgs boson's properties. Also presented are the first differential cross section measurements for the Higgs boson as measured in the diphoton decay channel. Distributions in data are unfolded to particle level and compared with the latest Monte Carlo event generators for gluon-gluon fusion. Many distributions concentrate on the kinematics of the Higgs boson produced in association with jets. Finally, a proposal for a 1-jet VBF region for the high-luminosity LHC is proposed based on the difference in rapidity between the Higgs boson and the leading jet. This region shows good discrimination power against gluon-gluon fusion events and has been shown to discriminate against beyond the Standard Model couplings.
Download or read book Measurements of Higgs Boson Production Cross sections in the H tau plus tau minus Decay Channel in Pp Collisions at square Root s written by 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:
Download or read book Measurement of Differential and Integrated Fiducial Cross Sections for Higgs Boson Production in the Four lepton Decay Channel in Pp Collisions at sqrt s written by and published by . This book was released on 2016 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integrated fiducial cross sections for the production of four leptons via the H → 4l decays (l = e, [mu]) are measured in pp collisions at $ \sqrt{s}=7 $ and 8TeV. Measurements are performed with data corresponding to integrated luminosities of 5.1 fb$^{-1}$ at 7TeV, and 19.7 fb$^{-1}$ at 8 TeV, collected with the CMS experiment at the LHC. Differential cross sections are measured using the 8 TeV data, and are determined as functions of the transverse momentum and rapidity of the four-lepton system, accompanying jet multiplicity, transverse momentum of the leading jet, and difference in rapidity between the Higgs boson candidate and the leading jet. A measurement of the Z → 4l cross section, and its ratio to the H → 4l cross section is also performed. All cross sections are measured within a fiducial phase space defined by the requirements on lepton kinematics and event topology. Here, the integrated H → 4l fiducial cross section is measured to be 0.56$_{-0.44}^{+0.67}$ (stat)$_{-0.06}^{+0.21}$ (syst) fb at 7 TeV, and 1.11$_{-0.35}^{+0.41}$ (stat)$_{-0.10}^{+0.14}$ (syst) fb at 8 TeV. The measurements are found to be compatible with theoretical calculations based on the standard model.
Download or read book Measurements of the Total and Differential Higgs Boson Production Cross Sections Combining the H 2 gamma gamma and H 2 ZZ 2 4l Decay Channels at arrow written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the total and differential cross sections of Higgs boson production are performed using 20.3 fb-1 of pp collisions produced by the Large Hadron Collider at a center-of-mass energy of [arrow]" = 8 TeV and recorded by the ATLAS detector. Cross sections are obtained from measured H 2![gamma][gamma] and H 2!ZZ* 2!4l event yields, which are combined accounting for detector efficiencies, fiducial acceptances, and branching fractions. Differential cross sections are reported as a function of Higgs boson transverse momentum, Higgs boson rapidity, number of jets in the event, and transverse momentum of the leading jet. The total production cross section is determined to be [sigma]pp2! = 33.0 " 5.3 (stat) " 1.6 (syst) pb. The measurements are compared to state-of-the-art predictions.
Download or read book Higgs Boson Production with a Top Quark Pair in the Diphoton Channel Double Higgs Production in the Bb diphoton Channel and Inner Tracker Upgrade with the Atlas Detector at the Large Hadron Collider written by Alex Zeng Wang and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the discovery of the Higgs boson in 2012, the diphoton ([gamma][gamma]) decay channel of the Higgs boson has been one of the most potent channels due to the contrast between the smoothly falling background and sharply peaked signal in the diphoton invariant mass. In 2018, with up to 80 fb-1 of data at [square root]s = 13 TeV, ATLAS observed Higgs boson production in association with a pair of top quarks (ttH) with a significance of 5.8 [sigma] by combining measurements in the [gamma][gamma], bb, ZZ, and multi-lepton Higgs decay channels. The ttH production cross-section was measured to be 670 [plus or minus] 90 (stat) +110 -100 (syst) fb. The diphoton channel was one of the main contributors to this result, alone providing a significance of 4.1 [sigma]. With 140 fb-1, a search for non-resonant Higgs pair production in the bb[gamma][gamma] final state was performed. No significant signal was observed and upper limits at 95% confidence level were set. The observed limit on the SM cross-section was 130 fb, or 4.2 times the predicted value. The observed Higgs trilinear coupling modifier was constrained to be between [-1.5, 6.7]. Both the ttH (H [rightwards arrow] [gamma][gamma]) and HH bb[gamma][gamma] analyses will benefit tremendously from the increased statistics expected from the High-Luminosity LHC (HL-LHC). To ensure the continued efficiency of the detector in the harsh HL-LHC environment, ATLAS will install a new Inner Tracker (ITk) consisting of silicon pixel sensors in its innermost layer. At SLAC National Accelerator Laboratory, a variety of electrical tests are performed for the construction of a prototype integrated pixel system, in order to provide early feedback and validation of the ITk design.
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.
Download or read book Measurements of the Total and Differential Higgs Boson Production Cross Sections Combining the H u2192 and H u2192 ZZ u2192 4l Decay Channels at u221A s written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the total and differential cross sections of Higgs boson production are performed using 20.3 fb-1 of pp collisions produced by the Large Hadron Collider at a center-of-mass energy of √s = 8 TeV and recorded by the ATLAS detector. Cross sections are obtained from measured H → ?? and H → ZZ* → 4l event yields, which are combined accounting for detector efficiencies, fiducial acceptances, and branching fractions. Differential cross sections are reported as a function of Higgs boson transverse momentum, Higgs boson rapidity, number of jets in the event, and transverse momentum of the leading jet. The total production cross section is determined to be ?pp→H = 33.0 ± 5.3 (stat) ± 1.6 (syst) pb. The measurements are compared to state-of-the-art predictions.
Download or read book Measurement of Higgs boson Production Cross sections and Test of CP Invariance in Vector boson Fusion Production in the H Lep Had Decay Mode with the ATLAS Detector written by Dirk Sammel and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This thesis presents a measurement of the Higgs-boson production cross-section and a test of CP invariance in vector-boson fusion production in the semileptonic final state of the H->tau tau decay channel. Both analyses use proton-proton collision data corresponding to an integrated luminosity of 36.1 fb^-1 recorded with the ATLAS detector at a center-of-mass energy of 13 TeV. The events are divided into categories that target the specific kinematics of the gluon fusion- and the vector-boson fusion production processes of the Higgs boson. A maximum-likelihood fit in the reconstructed di-tau mass is performed to extract the H->tau tau cross-section. A signal excess with an observed significance of 2.4 standard deviations is found under the background-only hypothesis, whereas the expected significance is 2.6 standard deviations. The resulting H->tau tau cross-section is 3.13 +1.53/-1.33 pb, which is in agreement with the prediction by the Standard Model. In combination with the fully leptonic- and fully hadronic final states of the H->tau tau decay channel, the resulting cross-section is 3.77 +1.06/-0.95 pb, which is again consistent with the prediction by the Standard Model. The obtained observed significance is 4.4 standard deviations with an expected significance of 4.1 standard deviations. Further combination with the result of the search for the H->tau tau decay with data recorded at center-of-mass energies of 7 and 8 TeV yields an observed significance of 6.4 standard deviation with an expected significance of 5.4 standard deviations. To test CP invariance in the coupling between the Higgs boson and the electroweak gauge bosons, the production of the Higgs boson via vector-boson fusion is studied. This production process is separated from other processes by using a machine learning approach in form of Boosted Decision Trees. An Effective Field Theory approach is used to expand the Lagrangian of the Standard Model with additional CP-odd terms, quantified by the parameter dtilde. Maximum-likelihood fits are performed in the CP-odd Optimal Observable to set constraints on dtilde. The observed confidence interval at 68.3% confidence level is [-0.006,0.089], whereas the expected confidence interval is [-0.064,0.065]. The combination with the fully leptonic- and fully hadronic final states of the H->tau tau decay channel yields an observed 68.3% confidence interval of [-0.090,0.035] with an expected confidence interval of [-0.035,0.033]. In the combination, also an expected confidence interval at 95% confidence level of [-0.21,015] is obtained. All the results are in agreement with dtilde=0 as predicted by the Standard Model
Download or read book Discovery and Measurement of the Higgs Boson in the WW Decay Channel written by David Hall and published by . This book was released on 2015 with total page 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.
Download or read book Measurement and Interpretation of Higgs Boson Differential Cross Sections Inthe Diphoton Decay Channel and Measurement of the Photon Identification Effiviency in the ATLAS Experiment written by Früd Braren and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cross Section Measurements of the Higgs Boson in the Diphoton Decay Channel Using Proton Proton Collision Data Recorded by the ATLAS Detector at Centre of Mass Energies of 7 TeV and 8 TeV written by James Lacey and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
