Download or read book Measurement of the Higgs boson Coupling to Tau leptons and Combined Measurements of Higgs boson Properties at Sqrt s written by Théo Megy and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The measurement of the Higgs-boson coupling to tau-leptons, based on an integrated luminosity of 36.1 ifb recorded at a centre-of-mass energy of 13 TeV by the ATLAS detector, is presented in this thesis. The analysis considers all combinations of leptonic and hadronic decays of tau-leptons, and targets the main two production modes of the Higgs boson, gluon Fusion and Vector-Boson Fusion. The inclusive cross section of the H->tautau decay channel is measured as 3.77 +1.06-0.95 (+0.60-0.59 (Stat.) +0.87-0.74 (Syst.)) pb, which corresponds to a deviation from the background-only hypothesis with an observed (expected) significance of 4.4 (4.1) standard deviations. In addition, the measurement of cross sections in the framework of Simplified Template Cross Sections is discussed. All measurement are in agreement with predictions of the Standard Model. The combined measurement of Higgs-boson properties is also presented, based on up to 79.8 ifb of data recorded at sqrt(s) = 13 TeV by the ATLAS detector. An observation of the four main production modes (ggF, VBF, VH and ttH+tH) and of four of the five main decay channels (H->gammagamma, H->ZZ, H->WW and H->bb) of the Higgs boson is achieved. In particular, the deviation from the background-only hypothesis with an observed (expected) significance of 6.5 (5.3) standard deviations for the VBF production mode is the first observation of this process by a single experiment. Measurements in the scope of the kappa-framework and of Simplified Template Cross Sections are also discussed. All the performed measurements are compatible with the Standard-Model expectations

Download or read book Measurement of the Higgs boson Coupling to Tau leptons and Combined Measurements of Higgs boson Properties at square Roots s written by Théo J. Megy and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The measurement of the Higgs-boson coupling to tau-leptons, based on an integrated luminosity of 36.1 ifb recorded at a centre-of-mass energy of 13 TeV by the ATLAS detector, is presented in this thesis. The analysis considers all combinations of leptonic and hadronic decays of tau-leptons, and targets the main two production modes of the Higgs boson, gluon Fusion and Vector-Boson Fusion. The inclusive cross section of the H->tautau decay channel is measured as 3.77 +1.06-0.95 (+0.60-0.59 (Stat.) +0.87-0.74 (Syst.)) pb, which corresponds to a deviation from the background-only hypothesis with an observed (expected) significance of 4.4 (4.1) standard deviations. In addition, the measurement of cross sections in the framework of Simplified Template Cross Sections is discussed. All measurement are in agreement with predictions of the Standard Model. The combined measurement of Higgs-boson properties is also presented, based on up to 79.8 ifb of data recorded at sqrt(s) = 13 TeV by the ATLAS detector. An observation of the four main production modes (ggF, VBF, VH and ttH+tH) and of four of the five main decay channels (H->gammagamma, H->ZZ, H->WW and H->bb) of the Higgs boson is achieved. In particular, the deviation from the background-only hypothesis with an observed (expected) significance of 6.5 (5.3) standard deviations for the VBF production mode is the first observation of this process by a single experiment. Measurements in the scope of the kappa-framework and of Simplified Template Cross Sections are also discussed. All the performed measurements are compatible with the Standard-Model expectations.

Download or read book Measurement of the Higgs Boson Coupling to Tau Leptons in Proton proton Collisions at square Root s written by Frank Sauerburger and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Higgs Boson Properties Using Its Decay to a Pair of tau Leptons in Proton proton Collisions at s written by Doyeong Kim and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Compact Muon Solenoid (CMS) detector has successfully operated with the Large Hadron Collider (LHC) collisions since 2010, leading to the Higgs boson discovery in 2012 by the CMS and ATLAS collaborations. The analyses of data taken during Run 2 (2016-2018) has already led to many interesting results about the properties of the Higgs boson and for the most part they are compatible in the context of the standard model (SM) so far. These studies are important because the SM appears to be an approximation of a more general theory. Precise studies of the Higgs boson's interactions with the known matter and force particles are essential to reveal the microscopic deviations from the SM prediction. One of such interactions is Yukawa couplings of the Higgs boson and fermions. The H → [tau tau] decay is the most sensitive fermionic decay mode that allows direct probing of this interaction. This thesis presents a study of the Higgs boson properties by observing its decay to a pair of tau leptons and testing evidence of non-SM interactions in the Higgs boson production. The results exploit the data collected by the CMS detector during LHC Run-2, in proton-proton collisions with a center-of-mass energy of 13 TeV. Firstly, the Higgs bosons' properties were explored by two complementary approaches by measuring its cross sections. Thanks to the observation of the H → [tau tau] decay in 2016, we can measure the total cross section with higher precision. Furthermore, in the first analysis, the cross sections of different Higgs productions were scrutinized using fine selections within each Higgs production mode which are mutually exclusive using the Simplified Template Cross Section (STXS) framework, proposed by the LHC Higgs Cross Section Working Group. In the second analysis, the first-ever measurement of the inclusive and differential fiducial cross sections for the Higgs boson production decaying to a pair of tau leptons was presented. In the third analysis, a search for anomalous couplings in the Higgs production vertex, including Charge-Parity (CP) violating couplings, is also performed targeting Higgs boson production via gluon fusion in association with two jets and vector boson fusion. None of these analyses has found any hint of new physics beyond the SM, but stringent limits on anomalous Higgs boson couplings to data were set and cross sections of the Higgs bosons in smaller phase spaces were precisely measured.

Download or read book Measurements of the CP Properties of the Higgs Boson Couplings to Tau Leptons and Top Quarks with the CMS Experiment written by Albert Kenneth Dow 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 A Study of the Standard Model Higgs Boson Decaying to a Pair of Tau Leptons with the CMS Detector at the LHC written by Tyler Henry Ruggles and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a 5.5 standard deviation observation of the Higgs boson decaying to fermions using the data collected at the LHC at 13 TeV center-of-mass energy. The studied dataset corresponds to an integrated luminosity of 35.9 inverse femtobarns. The best fit signal strength for the H to tau tau process is measured to be mu = 1.24 ^{+0.29}/{-0.27}, consistent with standard model predictions. Unique event categories are used targeting the leading Higgs boson production processes, gluon fusion, vector boson fusion, and associated production. This provides signal regions sensitive to Higgs boson couplings to both fermions and vector bosons. These two Higgs boson couplings are measured and are consistent with standard model predictions within one standard deviation. This 5.5 standard deviation observation of the H to tau tau process and the consistency of the Higgs boson couplings with the standard model provide confirmation of the Higgs boson Yukawa couplings to fermions. This is evidence that the Higgs field provides mass for the tau lepton in addition to the vector bosons.

Download or read book Discovery of the Higgs Boson Measurements of Higgs Boson Properties and Search for High Mass Beyond the Standard Model Scalar Particle in the Diphoton Final State with the ATLAS Detector at the Large Hadron Collider written by Hongtao Yang and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: With 4.8~$\rm{fb}^{-1}$ of proton-proton collision data collected at $\sqrt{s}=7~\rm{TeV}$ in 2011, and 5.9~$\rm{fb}^{-1}$ collected at $\sqrt{s}=8~\rm{TeV}$ in 2012 by the ATLAS detector at the Large Hadron Collider, an excess of 4.5 standard deviations from the background-only hypothesis is observed near 126.5~GeV in the diphoton invariant mass spectra. Along with the excesses observed in the $H \rightarrow ZZ^{(*)}\rightarrow \ell\ell\ell\ell$ and $H \rightarrow WW^{(*)}\rightarrow \ell\nu\ell\nu$ channels, the observation of a Higgs-like particle is established at 6.0 standard deviations level. With more data accumulated during LHC Run~1, the measurements of Higgs boson couplings and mass in the $H\to\gamma\gamma$ channel are conducted by the ATLAS experiment based on 4.5~$\rm{fb}^{-1}$ of proton-proton collisions at $\sqrt{s}=7~\rm{TeV}$ collected in 2011, and 20.3~$\rm{fb}^{-1}$ at $\sqrt{s}=8~\rm{TeV}$ collected in 2012. The combined signal strength, defined as number of observed Higgs boson decays to diphoton divided by the corresponding Standard Model prediction, is measured to be $1.17 \ ^{+0.28}_{-0.26}$ assuming the Higgs boson mass being 125.4~$\rm{GeV}$. The signal strengths for individual Higgs boson production processes are also measured, and are found to be in good consistency with the Standard Model. The mass of the Higgs boson is measured in $H\to\gamma\gamma$ channel by the ATLAS experiment to be $125.98 \pm 0.50$~\GeV. This measurement is combined with the ones from ATLAS $H \rightarrow ZZ^{(*)}\rightarrow \ell\ell\ell\ell$ as well as CMS $H\to\gamma\gamma$ and $H \rightarrow ZZ^{(*)}\rightarrow \ell\ell\ell\ell$. The Higgs boson mass measured from the combination is $125.09\pm0.24~\rm{GeV}$. With LHC center-of-mass energy increased to 13~TeV, a search for high mass Beyond the Standard Model scalar resonance is performed in the diphoton decay channel based on 15.4~$\rm{fb}^{-1}$ of proton-proton collision data collected by the ATLAS detector during 2015 and 2016. While a notable wide excess was first observed in the diphoton invariant mass spectrum from the 2015 data (3.2~$\rm{fb}^{-1}$) with mass near 750~GeV, it is not confirmed by the 2016 data with much higher statistics (12.4~$\rm{fb}^{-1}$). Limits on the production cross section times branching ratio of such resonances are set.

Download or read book The God Particle written by Leon M. Lederman and published by Houghton Mifflin Harcourt. This book was released on 2006 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fascinating tour of particle physics from Nobel Prize winner Leon Lederman. At the root of particle physics is an invincible sense of curiosity. Leon Lederman embraces this spirit of inquiry as he moves from the Greeks' earliest scientific observations to Einstein and beyond to chart this unique arm of scientific study. His survey concludes with the Higgs boson, nicknamed the God Particle, which scientists hypothesize will help unlock the last secrets of the subatomic universe, quarks and all--it's the dogged pursuit of this almost mystical entity that inspires Lederman's witty and accessible history.

Download or read book Search for Additional Higgs Bosons Decaying to Tau Leptons and Measurement of the CP Properties of the Higgs Yukawa Coupling to Top Quarks Using the CMS Detector written by Daniel Winterbottom and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measuring the CP Nature of the Yukawa Coupling Between the Higgs Boson and Tau Leptons written by Mohammad Hassan Hassanshahi 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 the Higgs Boson Coupling with Tau Leptons and Search for an Additional Neutral MSSM Higgs Bosob with the ATLAS Detector written by Damián Alvarez Piqueras and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combined Measurement of the Higgs Boson Mass in pp Collisions at sqrt s written by and published by . This book was released on 2015 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the Higgs boson mass is presented based on the combined data samples of the ATLAS and CMS experiments at the CERN LHC in the H 2![gamma][gamma] and H 2!ZZ 2!4l decay channels. These results are obtained from a simultaneous fit to the reconstructed invariant mass peaks in the two channels and for the two experiments. We measured masses from the individual channels and the two experiments are found to be consistent among themselves. Furthermore, the combined measured mass of the Higgs boson is mH = 125.09 " 0.21(stat) " 0.11(syst)GeV.

Download or read book Measurements of Higgs Boson Production and Couplings in the Four lepton Channel in pp Collisions at Center of mass Energies of 7 and 8 TeV 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:

Download or read book Search for Neutral MSSM Higgs Bosons Decaying to Pairs of tau Leptons at square Root of S written by Evan Klose Friis and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes a search for the Higgs boson, a new particle predicted by a theory called the minimal supersymmetric extension to the standard model (MSSM). The standard model of particle physics, the MSSM, and Higgs boson phenomenology are introduced briefly. The search presented in this thesis uses a single final state configuration, in which the Higgs boson decays to two tau leptons, with one tau decaying to a muon and neutrinos, and the other decaying to pions and a single neutrino. Two new methods are introduced in this analysis, the Tau Neural Classifier tau identification algorithm, and the Secondary Vertex fit tau pair mass reconstruction method. Both methods are discussed in detail. The analysis uses the 2010 dataset from the Compact Muon Solenoid (CMS) experiment, which contains 36 pb−1 of integrated luminosity at a center of mass energy of 7 TeV. In total, 573 events are selected in the analysis. We fit the observed tau pair mass spectrum and measure the composition of the events. The result is compatible with the standard model expectation. No excess of signal events is observed, and we set an upper limit on the cross section times branching ratio of a Higgs boson. This limit is interpreted in the parameter space of the MSSM.

Download or read book Evidence for the Higgs boson Yukawa Coupling to Tau Leptons 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:

Download or read book Evidence for the Higgs Boson Yukawa Coupling to Tau Leptons with the ATLAS Detector written by C. Jeske and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of Higgs Boson Production Via Gluon Fusion and Vector boson Fusion in the H WW Decay Mode with the ATLAS Experiment at the LHC at square Root s written by Ralf Gugel and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: On the 4 th of July 2012 the observation of a new neutral particle was announced by the ATLAS [1] and CMS [2] Collaborations. This particle is by now generally considered as the Higgs boson H predicted [3, 4] in the Standard Model of particle physics. Its mass of m H = 125.09 ± 0.24 GeV [5] implies a rich set of final states which allow for experimental studies in regards to this particle and searches for deviations from the properties predicted by the Standard Model. In this thesis a measurement of the gluon-fusion and vector-boson fusion production cross sections times H→WW* branching ratio is presented using final states with one electron and one muon. The measurement is based on proton- proton collisions with an integrated luminosity of 36.1 fb -1 √ recorded with the ATLAS detector at the CERN Large Hadron Collider ( LHC ) at s = 13 TeV in 2015 and 2016. Signal-like events are selected in categories with different jet multiplicities. The results are extracted by means of a binned maximum-likelihood fit. To this end, either distributions in multiple discriminant variables or the response of a multivariate classifier are used depending on the category. The results are found to be well compatible with the Standard Model predictions. This analysis is extrapolated to estimate the future precision of such a measurement at the end of the High-Luminosity LHC programme [6]. This extrapolated analysis is combined with analogously extrapolated analyses targeting other production and decay modes of the Higgs boson. Based on this combination the expected precision is determined for future measurements of couplings between the Higgs boson and other particles. Thereby an estimation is given for the anticipated sensitivity of these analyses to signs of physics beyond the Standard Model. In addition studies are presented to identify sources of electron charge misidentification in the reconstruction algorithms employed in the ATLAS Collaboration.