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Book Search for the Higgs Boson in the All Hadronic Final State Using the CDF II Detector

Download or read book Search for the Higgs Boson in the All Hadronic Final State Using the CDF II Detector written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis reports the result of a search for the Standard Model Higgs boson in events containing four reconstructed jets associated with quarks. For masses below 135 GeV/c2, the Higgs boson decays to bottom-antibottom quark pairs are dominant and result primarily in two hadronic jets. An additional two jets can be produced in the hadronic decay of a W or Z boson produced in association with the Higgs boson, or from the incoming quarks that produced the Higgs boson through the vector boson fusion process. The search is performed using a sample of s = sqrt(1.96) TeV proton-antiproton collisions corresponding to an integrated luminosity of 9.45 fb-1 recorded by the CDF II detector. The data are in agreement with the background model and 95% credibility level upper limits on Higgs boson production are set as a function of the Higgs boson mass. The median expected (observed) limit for a 125 GeV/c2 Higgs boson is 11.0 (9.0) times the predicted standard model rate.

Book Discovery Of The Higgs Boson

Download or read book Discovery Of The Higgs Boson written by Aleandro Nisati and published by World Scientific. This book was released on 2016-08-26 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: The recent observation of the Higgs boson has been hailed as the scientific discovery of the century and led to the 2013 Nobel Prize in physics. This book describes the detailed science behind the decades-long search for this elusive particle at the Large Electron Positron Collider at CERN and at the Tevatron at Fermilab and its subsequent discovery and characterization at the Large Hadron Collider at CERN. Written by physicists who played leading roles in this epic search and discovery, this book is an authoritative and pedagogical exposition of the portrait of the Higgs boson that has emerged from a large number of experimental measurements. As the first of its kind, this book should be of interest to graduate students and researchers in particle physics.

Book Combination of Searches for the Higgs Boson Using the Full CDF Data Set

Download or read book Combination of Searches for the Higgs Boson Using the Full CDF Data Set written by and published by . This book was released on 2013 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Perspectives for Higgs Boson Search in Full Hadronic Final States at CDF 2

Download or read book Perspectives for Higgs Boson Search in Full Hadronic Final States at CDF 2 written by Luca Scodellaro and published by . This book was released on 2001 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Search for a Standard Model Higgs Boson in the Channel  VH to VWW  with Leptons and Hadronic   tau  in the Full CDF Run II Data Set

Download or read book Search for a Standard Model Higgs Boson in the Channel VH to VWW with Leptons and Hadronic tau in the Full CDF Run II Data Set written by and published by . This book was released on 2015 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the results of the CDF search for a Standard Model Higgs boson decaying into a pair of W bosons with electrons, muons and hadronically decaying taus in the final state. In particular, we investigate a channel with three objects, two leptons and a tau. In 9.7 fb-1 of data we expect 40.0 ± 5.4 background events and 0.54 ± 0.05 signal events for a Higgs mass hypothesis of 160 GeV/c2, whereas in data we count 28 events. We set a 95% C.L. upper limit on [sigma]/[sigma]SM of 12.6 for a Higgs mass hypothesis of 160 GeV/c2. The expected 95% C.L. upper limit for the same mass is 12.4. Results for other ninete 0 GeV/c2 to 200 GeV/c2 are also presented.

Book Search for the Higgs Boson in the ZH to Uubb Channel at CDF Using Novel Multivariate Techniques

Download or read book Search for the Higgs Boson in the ZH to Uubb Channel at CDF Using Novel Multivariate Techniques written by Justin Robert Pilot and published by . This book was released on 2011 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: We present a search for the Standard Model Higgs Boson using the process ZH to uubb. We use a dataset corresponding to 9.2/fb of integrated luminosity from proton-antiproton collisions with center-of-mass energy 1.96 TeV at the Fermilab Tevatron, collected with the CDF II detector. This analysis benefits from several new multivariate techniques that have not been used in previous analyses at CDF. We use a multivariate function to select muon candidates, increasing signal acceptance while simultaneously keeping fake rates small. We employ an inclusive trigger selection to further increase acceptance. To enhance signal discrimination, we utilize a multi-layer approach consisting of expert discriminants. This multi-layer discriminant method helps isolate the two main classes of background events, t-tbar and Z+jets production. It also includes a flavor separator, to distinguish light flavor jets from jets consistent with the decay of a B-hadron. With this novel multi-layer approach, we proceed to set limits on the ZH production cross section times branching ratio. For a Higgs boson with mass 115 GeV/c^2, we observe (expect) a limit of 8.0 (4.9) times the Standard Model prediction.

Book A Search for the Standard Model Higgs Boson in Four jet Final States in Center of mass Energies Near 193 GeV with the ALEPH Detector at LEP

Download or read book A Search for the Standard Model Higgs Boson in Four jet Final States in Center of mass Energies Near 193 GeV with the ALEPH Detector at LEP written by Stephen R. Armstrong and published by . This book was released on 1998 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book A Search for the Higgs Boson in the  ZH  Dilepton Decay Channel at CDF II

Download or read book A Search for the Higgs Boson in the ZH Dilepton Decay Channel at CDF II written by and published by . This book was released on 2009 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes a search for the Standard Model Higgs boson produced in association with the Z boson via Higgs-strahlung at the CDF II detector at the Tevatron. At a Higgs boson mass between 100 GeV/c2 and 135 GeV/c2, the primary Higgs decay mode is to a pair of b quarks. The associated Z boson can decay to a pair of electrons or muons, allowing detection of a final event signature of two visible leptons and two b quarks. This final state allows reduction of large QCD backgrounds compared to a hadronic Z boson decay, leading to a more sensitive search. To increase sensitivity, standard model matrix element probabilities for ZH signal and the dominant backgrounds are used as components to a likelihood fit in signal fraction. In 2.7 fb−1 of CDF II data, we see no evidence of production of a Higgs boson with a mass between 100 GeV c2 and 150 GeV/c2. Using the Feldman-Cousins technique to set a limit, at 95% coverage and a Higgs boson mass of 115 GeV/c2, the median expected limit was 12.1 x [sigma]{sub SM} and a limit of 8.2 x [sigma]{sub SM} was observed, where [sigma]{sub SM} is the NNLO theoretical cross section of p{bar p} →ZH → l +l -b{bar b} at √s=1.96 TeV . Cross section limits are computed at a range of Higgs boson mass values between 100 GeV/c 2 and 150 GeV/c2.

Book Search for the Higgs Boson in the  ZH to mu   mu   B bar b   Channel at CDF Using Novel Multivariate Techniques

Download or read book Search for the Higgs Boson in the ZH to mu mu B bar b Channel at CDF Using Novel Multivariate Techniques written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a search for the Standard Model Higgs Boson using the process $ZH\to\mu^+\mu^- b\bar{b}$. We use a dataset corresponding to 9.2 fb$^{-1}$ of integrated luminosity from proton-antiproton collisions with center-of-mass energy 1.96 TeV at the Fermilab Tevatron, collected with the CDF II detector. This analysis benefits from several new multivariate techniques that have not been used in previous analyses at CDF. We use a multivariate function to select muon candidates, increasing signal acceptance while simultaneously keeping fake rates small. We employ an inclusive trigger selection to further increase acceptance. To enhance signal discrimination, we utilize a multi-layer approach consisting of expert discriminants. This multi-layer discriminant method helps isolate the two main classes of background events, $t\bar{t}$ and $Z$+jets production. It also includes a flavor separator, to distinguish light flavor jets from jets consistent with the decay of a $B$-hadron. Wit h this novel multi-layer approach, we proceed to set limits on the $ZH$ production cross section times branching ratio. For a Higgs boson with mass 115 GeV/$c^2$, we observe (expect) a limit of 8.0 (4.9) times the Standard Model prediction.

Book Higgs Boson Searches at CDF

Download or read book Higgs Boson Searches at CDF written by and published by . This book was released on 2009 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are presented on searches for standard model and non-standard model production of a Higgs boson in pbar-p collisions at (square root)s = 1.96 TeV with the CDF II detector at the Fermilab Tevatron. Using data corresponding to 2-3.6 1/fb of integrated luminosity, searches are performed in a number of different production and decay modes. No excess in data above that expected from backgrounds is observed; therefore, we set upper limits on the production cross section times branching fraction as a function of the Higgs boson mass.

Book A Search for the Higgs Boson Produced in Association with Top Quarks in Multilepton Final States at ATLAS

Download or read book A Search for the Higgs Boson Produced in Association with Top Quarks in Multilepton Final States at ATLAS written by Chris Lester and published by . This book was released on 2015 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents preliminary results of a search for Higgs boson production in association with top quarks in multilepton final states. The search was conducted in the 2012 dataset of proton-proton collisions delivered by the CERN Large Hadron Collider at a center-of-mass energy of 8 TeV and collected by the ATLAS experiment. The dataset corresponds to an integrated luminosity of 20.3 inverse femtobarns. The analysis is conducted by measuring event counts in signal regions distinguished by the number of leptons (2 same-sign, 3, and 4), jets and b-tagged jets present in the reconstructed events. The observed events in the signal regions constitute an excess over the expected number of background events. The results are evaluated using a frequentist statistical model. The observed exclusion upper limit at the 95 % confidence level is 5.50 times the predicted Standard Model production cross section for Higgs production in association with top quarks. The fitted value of the ratio of the observed production rate to the expected Standard Model production rate is 2.83 + 1.58 - 1.35.

Book A Search for the Standard Model Higgs Boson with Missing Mass Final States at Center of mass Energy at 188 6 GeV with the ALEPH Detector at LEP

Download or read book A Search for the Standard Model Higgs Boson with Missing Mass Final States at Center of mass Energy at 188 6 GeV with the ALEPH Detector at LEP written by Xidong Wu and published by . This book was released on 2000 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Search for the Standard Model Higgs Boson in the Diphoton Final State in  p bar p   Collisions at   sqrt s

Download or read book Search for the Standard Model Higgs Boson in the Diphoton Final State in p bar p Collisions at sqrt s written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a search for the Standard Model Higgs boson decaying into a pair of photons produced in p$p\bar{p}$ collisions with a center of mass energy of 1.96 TeV. The results are based on data corresponding to an integrated luminosity of 10 fb-1 collected by the CDF II detector. Higgs boson candidate events are identified by reconstructing two photons in either the central or plug regions of the detector. The acceptance for identifying photons is significantly increased by using a new algorithm designed to reconstruct photons in the central region that have converted to an electron-positron pair. In addition, a new neural network discriminant is employed to improve the identification of non-converting central photons. No evidence for the Higgs boson is observed in the data, and we set an upper limit on the cross section for Higgs boson production multiplied by the H 2![gamma][gamma] branching ratio. For a Higgs boson mass of 125 GeV/c 2, we obtain an observed (expected) limit of 12.2 (10.8) times the Standard Model prediction at the 95% credibility level.

Book Search for the Higgs Boson with the CDF Experiment at Tevatron

Download or read book Search for the Higgs Boson with the CDF Experiment at Tevatron written by and published by . This book was released on 2005 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for a low-mass SM Higgs-Boson in the channel WH → lvb$\bar{b}$ has been performed using neural networks. The data were taken by the CDF experiment at the p-$\bar{p}$ collider Tevatron from 2000-2003, corresponding to in integrated luminosity of Lint = 162 pb-1 at a CMS-energy of √s = 1.96 TeV. 95% confidence level upper limits are set on [sigma] × BR, the product of the production cross section times the Branching ratio, as a function of the Higgs boson mass. Cross sections above 8 pb are excluded for six different Higgs masses between 110 GeV/c2 and 150 GeV/c2. The required integrated luminosities for a 95% C.L. exclusion, 3[sigma] evidence and 5[sigma] discovery are calculated.