Download or read book Heavy Neutral Particle Decays to Tau Pairs written by Michail Bachtis and published by Springer. This book was released on 2016-08-27 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presented in this thesis spans a wide range of experimental particle physics subjects, starting from level-1 trigger electronics to the final results of the search for Higgs boson decay and to tau lepton pairs. The thesis describes an innovative reconstruction algorithm for tau decays and details how it was instrumental in providing a measurement of Z decay to tau lepton pairs. The reliability of the analysis is fully established by this measurement before the Higgs boson decay to tau lepton pairs is considered. The work described here continues to serve as a model for analysing CMS Higgs to tau leptons measurements.
Download or read book Heavy Neutral Particle Decays to Tau Pairs in Proton Collisions at Sqrt s written by and published by . This book was released on 2012 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes a study of the tau-pair final state in proton collisions at a center of mass energy of 7 TeV using the CMS Experiment at the CERN Large Hadron Collider. Tau leptons usually decay to hadrons and their efficient detection is very challenging in a hadronic environment. A novel tau reconstruction algorithm that maintains tau detection efficiency for low background rates was developed. Events were then selected from the CMS 2011 data sample in three T T final states depending on the tau decays: mu + T (h), e+ T (h) , e+mu where T (h) denotes a hadronic tau decay. Those events were used to measure the Z-boson production cross section where Z yields T T . A search for the Standard Model and Minimal Supersymmetric Standard Model (MSSM) Higgs bosons was also performed. No signal was observed in the Higgs search and stringent new bounds were set for the SM Higgs production and in the MSSM parameter space.
Download or read book Heavy Neutral Particle Decays to Tau Pairs written by Michail Bachtis and published by Springer Science & Business Media. This book was released on 2013-12-13 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presented in this thesis spans a wide range of experimental particle physics subjects, starting from level-1 trigger electronics to the final results of the search for Higgs boson decay and to tau lepton pairs. The thesis describes an innovative reconstruction algorithm for tau decays and details how it was instrumental in providing a measurement of Z decay to tau lepton pairs. The reliability of the analysis is fully established by this measurement before the Higgs boson decay to tau lepton pairs is considered. The work described here continues to serve as a model for analysing CMS Higgs to tau leptons measurements.
Download or read book Search for a Heavy Neutral Particle Decaying to E Mu E Tau Or Mu Tau in Pp Collisions 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: This Letter presents a search for a heavy neutral particle decaying into an opposite-sign different-flavor dilepton pair, e±?∓, e±?∓, or ?±?∓ using 20.3 fb-1 of pp collision data at √s=8 TeV collected by the ATLAS detector at the LHC. The numbers of observed candidate events are compatible with the standard model expectations. Limits are set on the cross section of new phenomena in two scenarios: the production of ????????? in R-parity-violating supersymmetric models and the production of a lepton-flavor-violating Z' vector boson.
Download or read book Decays of the Tau Lepton written by Patricia Burchat and published by Ann Arbor, Mich. : University Microfilms International. This book was released on 1986 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for a Heavy Neutral Particle Decaying to E mu E tau Or mu tau in Pp Collisions 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:
Download or read book Decays of the Heavy Lepton Tau 1785 written by Craig Alan Blocker and published by . This book was released on 1980 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chaptong sani written by and published by . This book was released on 1920 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for Heavy Resonances Decaying to Tau Lepton Pairs in Proton proton Collisions at sqrt s 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 for heavy resonances that decay to tau lepton pairs is performed using proton-proton collisions at \sqrt{s}$ = 13 TeV. The data were collected with the CMS detector at the CERN LHC and correspond to an integrated luminosity of 2.2 inverse femtobarns. The observations are in agreement with standard model predictions. An upper limit at 95% confidence level on the product of the production cross section and branching fraction into tau lepton pairs is calculated as a function of the resonance mass. For the sequential standard model, the presence of Z' bosons decaying into tau lepton pairs is excluded for Z' masses below 2.1 TeV, extending previous limits for this final state. For the topcolor-assisted technicolor model, which predicts Z' bosons that preferentially couple to third-generation fermions, Z' masses below 1.7 TeV are excluded, representing the most stringent limit to date.
Download or read book Search for a Heavy Neutral Particle Decaying to E Mu E Tau Or Mu Tau in Pp Collisions at Root S 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 Study of Tau Lepton Decays to Three Charged Hadrons and One Neutral Pion written by Kregg E. Arms and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: We report a study of [tau] lepton decays to three charged hadrons and a [pi]0. We use (7.56 +/- 0.15) fb −1 of data collected with the CLEO III detector at the Y (4S) resonance, which corresponds to a total of (6.90 +/- 0.14) x 106 [tau]-pairs. Using both a Ring Imaging Cherenkov (RICH) detector and measurement of specific ionization energy loss (dE/dx) for particle identification, we report the first observation of the decay [tau]− [right arrow] K−[omega][tau neutrino]. We report the first statistically significant measurements of the branching fractions for [tau]− [right arrow] K−[pi][pi]−[pi]0[tau neutrino] (excluding K0), [tau]− [right arrow] K−K[pi]−[pi]0[tau neutrino] and the first published upper limit for [tau]− [right arrow] K−K+K−[pi]0[tau neutrino]. We also measure branching fractions for the decays, [tau]− [right arrow] h−[omega][tau neutrino], [tau]− [right arrow] [pi]−[omega][tau neutrino], [tau]− [right arrow] h−h+h−[pi]0[tau neutrino], and [tau]− [right arrow] [pi]−[pi]+[pi]−[pi]0[tau neutrino].
Download or read book Exotic Physics written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the results of a search for anomalous resonant production of tau lepton pairs with large invariant mass, the first such search using the CDF II Detector in Run II of the Tevatron p{bar p} collider. Such anomalous production could arise from various new physics processes. In a data sample corresponding to 195 pb−1 of integrated luminosity we predict 2.8 " 0.5 events from Standard Model background processes and observe 4. We use this result to set limits on the production of heavy scalar and vector particles decaying to tau lepton pairs.
Download or read book Search for Heavy Resonances Decaying to Taus in 7 TeV Proton proton Collisions at the Large Hadron Collider written by Alfredo Gurrola and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last few decades, the Standard Model (SM) of particle physics has been used as a means of understanding the world around us. However, there is an increasing amount of data that suggests the SM of particle physics only describes nature up to energies of the electroweak scale. Extensions to the SM have been developed as a means of explaining experimental observation. If these extensions are indeed the correct mathematical descriptions of nature, the Large Hadron Collider (LHC), located at the European Center for Nuclear Research (CERN) near Geneva, Switzerland, is expected to produce new and exciting physics signatures that can shed light on the evolution of our universe since the early hypothesized Big Bang. Of particular interest are models that may lead to events with highly energetic tau lepton pairs. In this dissertation, focus is placed on a possible search for new heavy gauge bosons decaying to highly energetic tau pairs using a data sample corresponding to an integrated luminosity of 36 pb−1 of proton-proton collisions at [square root of] s = 7 TeV collected with the CMS detector at the CERN LHC. The number of observed events in the data is in good agreement with the predictions for SM background processes. In the context of the Sequential SM, a Zʹ with mass less than 468 GeV/c2 is excluded at 95%credibility level, exceeding the sensitivity by the Tevatron experiments at the Fermi National Accelerator Laboratory.
Download or read book Tau Lepton Physics Proceedings Of The Second Workshop written by K K Gan and published by World Scientific. This book was released on 1993-04-08 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: The II International Workshop on Tau Lepton Physics was held in Ohio, USA in September 1992. Its purpose is to gather the experts on tau lepton physics to examine the current understanding of the tau lepton physics and to assess future prospects. A particular emphasis of the Workshop was a detailed examination of the '1-prong problem': the discrepancy between the inclusive measurement of one-charged-particle decay branching ratio and the sum of the exclusive decays. The Workshop also stimulated new ideas on tests of the Standard Model using the third generation lepton and assessed the future prospects of the lepton physics.
Download or read book Decays of the Tau Lepton written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Previous measurements of the branching fractions of the tau lepton result in a discrepancy between the inclusive branching fraction and the sum of the exclusive branching fractions to final states containing one charged particle. The sum of the exclusive branching fractions is significantly smaller than the inclusive branching fraction. In this analysis, the branching fractions for all the major decay modes are measured simultaneously with the sum of the branching fractions constrained to be one. The branching fractions are measured using an unbiased sample of tau decays, with little background, selected from 207 pb−1 of data accumulated with the Mark II detector at the PEP ee− storage ring. The sample is selected using the decay products of one member of the .gamma.gamma.− pair produced in e+e− annihilation to identify the event and then including the opposite member of the pair in the sample. The sample is divided into subgroups according to charged and neutral particle multiplicity, and charged particle identification. The branching fractions are simultaneously measured using an unfold technique and a maximum likelihood fit. The results of this analysis indicate that the discrepancy found in previous experiments is possibly due to two sources. First, the leptonic branching fractions measured in this analysis are about one standard deviation higher than the world average. The measured leptonic branching fractions correspond to a tau lifetime of (3.0 +- 0.2) x 10−13 s. Secondly, the total branching fraction to one charged hadron plus at least one neutral particle is measured to be (7 +- 3)% higher than the branching fraction expected from a combination of previous measurements and theoretical predictions. It is shown that decay modes involving the eta are not expected to contribute more than 3% to this excess.
Download or read book A Search for New Physics with High Mass Tau Pairs in Proton Anti proton Collisions at u221A s written by and published by . This book was released on 2005 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the results of a search for new particles decaying to tau pairs using the data corresponding to an integrated luminosity of 195 pb-1 collected from March 2002 to September 2003 with the CDF detector at the Tevatron. Hypothetical particles, such as Z' and MSSM Higgs bosons can potentially produce the tau pair final state. We discuss the method of tau identification, and show the signal acceptance versus new particle mass. The low-mass region, dominated by Z → ??, is used as a control region. In the high-mass region, we expect 2.8 ± 0.5 events from known background sources, and observe 4 events in the data sample. Thus no significant excess is observed, and we set upper limits on the cross section times branching ratio as a function of the masses of heavy scalar and vector particles.
Download or read book Search for High Mass Resonances Decaying to Tau Pairs at the CMS Experiment written by Carlos Andres Florez Bustos and published by . This book was released on 2011 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt:
