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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 Evidence of the Higgs Boson Decaying Into Two Photons

Download or read book Evidence of the Higgs Boson Decaying Into Two Photons written by Douglas R. Berry and published by . This book was released on 2013 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Search for a Higgs Boson Decaying Into   gamma    gamma to ell ell gamma  with Low Dilepton Mass in Pp Collisions at   sqrt s

Download or read book Search for a Higgs Boson Decaying Into gamma gamma to ell ell gamma with Low Dilepton Mass in Pp Collisions at sqrt s written by and published by . This book was released on 2015 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our search is described for a Higgs boson decaying into two photons, one of which has an internal conversion to a muon or an electron pair (ll?). The analysis is performed using proton–proton collision data recorded with the CMS detector at the LHC at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7 fb-1. The events selected have an opposite-sign muon or electron pair and a high transverse momentum photon. No excess above background has been found in the three-body invariant mass range 120 mll? 150 GeV, and limits have been derived for the Higgs boson production cross section times branching fraction for the decay H → ?*? → ll?, where the dilepton invariant mass is less than 20 GeV. A Higgs boson with mH=125 GeV has a 95% confidence level (CL) exclusion observed (expected) limit is 6.7 (5.9sup+2.8/supsub-1.8/sub ) times the standard model prediction. Additionally, an upper limit at 95% CL on the branching fraction of H → (J/?)? for the 125 GeV Higgs boson is set at 1.5 × 10

Book Search for Two Higgs Bosons in Final States Containing Two Photons and Two Bottom Quarks

Download or read book Search for Two Higgs Bosons in Final States Containing Two Photons and Two Bottom Quarks written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search is presented for the production of two Higgs bosons in final states containing two photons and two bottom quarks. Both resonant and nonresonant hypotheses are investigated. The analyzed data correspond to an integrated luminosity of 19.7 inverse femtobarns of proton-proton collisions at sqrt(s) = 8 TeV collected with the CMS detector. Good agreement is observed between data and predictions of the standard model (SM). Upper limits are set at 95% confidence level on the production cross section of new particles and compared to the prediction for the existence of a warped extra dimension. When the decay to two Higgs bosons is kinematically allowed, assuming a mass scale LambdaR = 1 TeV for the model, the data exclude a radion scalar at masses below 980 GeV. The first Kaluza-Klein excitation mode of the graviton in Randall-Sundrum models is excluded for masses between 325 and 450 GeV. Limits set on nonresonant production constrain the parameter space for anomalous Higgs boson couplings.

Book Search for a Higgs Boson Decaying Into   gamma   gamma to ell ell gamma  with Low Dilepton Mass in Pp Collisions at   sqrt s

Download or read book Search for a Higgs Boson Decaying Into gamma gamma to ell ell gamma with Low Dilepton Mass in Pp Collisions at sqrt s written by and published by . This book was released on 2015 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our search is described for a Higgs boson decaying into two photons, one of which has an internal conversion to a muon or an electron pair (ll[gamma]). The analysis is performed using proton-proton collision data recorded with the CMS detector at the LHC at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7 fb-1. The events selected have an opposite-sign muon or electron pair and a high transverse momentum photon. No excess above background has been found in the three-body invariant mass range 120

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 Higgs like Boson Decaying to Two Photons in  p bar p   Collisions at   sqrt s

Download or read book Search for a Higgs like Boson Decaying to Two Photons in p bar p Collisions at sqrt s written by and published by . This book was released on 2013 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a search for the Standard Model (SM) Higgs boson decaying to two photons using the 9.6 fb-1 of p$\bar{p}$ collisions at √s = 1.96 TeV collected by the D0 detector at the Tevatron from July 2002 to September 2011. The data corresponds to the complete data-set in the RunII period of the Tevatron. This thesis employs a multivariate technique, boosted decision trees, to optimize the discrimination of signal from background. No significant excess of data above theoretical prediction is observed, so limits on the ratio of the production cross section times the branching ratio to the SM value are set at 95% confidence level as a function of hypothetical Higgs boson mass. The expected and observed limits on this ratio are 8.7 and 12.8 respectively at 125 GeV. We also interpret the data in the fermiophobic Higgs model. The result has reached a sensitivity of 114 GeV, and we set a lower limit on the fermiophobic Higgs mass of MHf > 113 GeV.

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 248 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$par{p}$ 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 → ?? 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 Standard Model Higgs Boson Decaying Into Two Photons in Pp Collisions at Sqrt s

Download or read book Search for the Standard Model Higgs Boson Decaying Into Two Photons in Pp 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: A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.

Book Search for Higgs Boson Pair Production in the Two Bottom Quarks Plus Two Photons Final State in Pp Collisions at  square Root s

Download or read book Search for Higgs Boson Pair Production in the Two Bottom Quarks Plus Two Photons Final State in 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:

Book Observation of the Higgs Boson Decaying to WW to Leptons and Neutrinos

Download or read book Observation of the Higgs Boson Decaying to WW to Leptons and Neutrinos written by Nikolina Ilic and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Combined CDF and D0 Searches for the Standard Model Higgs Boson Decaying to Two Photons with Up to 8 2 Fb  1

Download or read book Combined CDF and D0 Searches for the Standard Model Higgs Boson Decaying to Two Photons with Up to 8 2 Fb 1 written by and published by . This book was released on 2011 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: We combine results from CDF and D0's direct searches for the standard model (SM) Higgs boson (H) produced in p{bar p} collisions at the Fermilab Tevatron at √s = 1.96 TeV, focusing on the decay H → [gamma][gamma]. We compute upper limits on the Higgs boson production cross section times the decay branching fraction in the range 100

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 a Fermiophobic Higgs Boson Decaying Into Two Photons at Cms

Download or read book Search for a Fermiophobic Higgs Boson Decaying Into Two Photons at Cms written by 張育瑋 and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: