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. 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 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 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 a Heavy Neutral Particle Decaying to E E Or 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. In addition, 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 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 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 Search for a Heavy Neutral Particle Decaying to E E Or 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 Ź vector boson.
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 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 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 Energy Research Abstracts written by and published by . This book was released on 1994-12 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Search for the Higgs Boson written by John V. Lee and published by Nova Publishers. This book was released on 2006 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Higgs boson is an undiscovered elementary particle, thought to be a vital piece of the closely fitting jigsaw of particle physics. Like all particles, it has wave properties akin to those ripples on the surface of a pond which has been disturbed; indeed, only when the ripples travel as a well defined group is it sensible to speak of a particle at all. In quantum language the analogue of the water surface which carries the waves is called a field. Each type of particle has its own corresponding field. The Higgs field is a particularly simple one -- it has the same properties viewed from every direction, and in important respects in indistinguishable from empty space. Thus physicists conceive of the Higgs field being "switched on", pervading all of space and endowing it with "grain" like that of a plank of wood. The direction of the grain in undetectable, and only becomes important once the Higgs' interactions with other particles are taken into account. for instance, particles call vector bosons can travel with the grain, in which case they move easily for large distances and may be observed as photons - that is, particles of light that we can see or record using a camera; or against, in which case their effective range is much shorter, and we call them W or Z particles. These play a central role in the physics of nuclear reactions, such as those occurring in the core of the sun. The Higgs field enables us to view these apparently unrelated phenomenon as two sides of the same coin; both may be described in terms of the properties of the same vector bosons. When particles of matter such as electrons or quarks (elementary constituents of protons and neutrons, which in turn constitute the atomic nucleus) travel through the grain, they are constantly flipped "head-over-heels". this forces them to move more slowly than their natural speed, that of light, by making them heavy.
Download or read book Astrophysics and Condensed Matter written by Thomas G. Hardwell and published by Nova Publishers. This book was released on 2008 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the latest research in two leading areas of physics - astrophysics and condensed matter.
