Download or read book Scalar Boson Decays to Tau Leptons written by Cécile Caillol and published by Springer. This book was released on 2017-11-15 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a study of the scalar sector in the standard model (SM), as well as various searches for an extended scalar sector in theories beyond the SM (BSM). The first part of the thesis details the search for an SM Higgs boson decaying to taus, and produced by gluon fusion, vector boson fusion, or associated production with a vector boson, leading to evidence for decays of the Higgs boson to taus. In turn, the second part highlights several searches for an extended scalar sector, with scalar boson decays to taus. In all of the analyses presented, at least one scalar boson decays to a pair of taus. The results draw on data collected by the Compact Muon Solenoid (CMS) detector during proton–proton collisions with a center-of-mass energy of 7 or 8 TeV.
Download or read book Search for a Very Light NMSSM Higgs Boson Produced in Decays of the 125 GeV Scalar Boson and Decaying Into Tau Leptons in Pp Collisions at the LHC written by Amithabh Shrinivas and published by . This book was released on 2016 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: A search for a very light Higgs boson decaying into a pair of tau leptons is presented within the framework of the next-to-minimal supersymmetric standard model(NMSSM). This search is based on a data set corresponding to an integrated luminosity of 19.7 fb-1 and 2.5 fb-1 of proton-proton collisions collected by the CMS experiment at a centre-of-mass energy of 8 TeV and 13 TeV respectively. The signal consists of the production of either of the two lightest scalars, h1 or h2, via gluon-gluon fusion and subsequent decay into a pair of the lightest Higgs bosons, a1 or h1. The h1 or h2 boson is identified with the observed state at a mass of 125 GeV. The analysis searches for decays of the a1(h1) states into pairs of tau leptons and covers a mass range for the a1(h1) boson of 4 to 15 GeV. The search reveals no significant excess in data above standard model background expectations, and an upper limit is set on the signal production cross section times branching fraction as a function of the a 1(h1) boson mass.
Download or read book Search for a Very Light NMSSM Higgs Boson Produced in Decays of the 125 GeV Scalar Boson and Decaying Into tau Leptons in Pp Collisions at sqrt s written by and published by . This book was released on 2015 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our search for a very light Higgs boson decaying into a pair of t leptons is presented within the framework of the next-to-minimal supersymmetric standard model. This search is based on a data set corresponding to an integrated luminosity of 19.7 fb-1 of proton-proton collisions collected by the CMS experiment at a centre-of-mass energy of 8 TeV. The signal is defined by the production of either of the two lightest scalars, h1 or h2, via gluon-gluon fusion and subsequent decay into a pair of the lightest Higgs bosons, a1 or h1. The h1 or h2 boson is identified with the observed state at a mass of 125 GeV. The analysis searches for decays of the a1 (h1) states into pairs of t leptons and covers a mass range for the a1 (h1) boson of 4 to 8 GeV. Furthermore, the search reveals no significant excess in data above standard model background expectations, and an upper limit is set on the signal production cross section times branching fraction as a function of the a1 (h1) boson mass. The 95% confidence level limit ranges from 4.5 pb at ma1 (mh1) = 8 GeV to 10.3 pb at ma1 (mh1) = 5 GeV.
Download or read book Search for Higgs Boson Decays to Long Lived Scalar Particles in Pp Interactions at 13 TeV written by Daniel Cipriano Diaz and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented in this thesis are the results of a novel search for exotic particles produced at the Large Hadron Collider (LHC). The search is performed using the data collected by the Compact Muon Solenoid (CMS) detector during the Run II period (2016 - 2018) of data taking. The data corresponds to a total integrated luminosity of 117fb-1, recorded at [square root of s] = 13 TeV. The search is performed in the topology where the Higgs boson is produced in association with a Z boson. The Higgs boson may decay to two exotic long-lived scalar particles (S). Final states where the long-lived particle decays to pairs of either b-quarks, d-quarks or [tau]-leptons are considered. No significant excess in the data with respect to the expected number of events containing decays to long-lived particles was observed. Limits are set on the branching ratio BR(H-SS) for the final states where the long-lived particle decays to pairs of b-quarks or d-quarks. No limit is set for the final state containing decays of the long-lived particles to pairs of [tau]-leptons. The limits reflect the most stringent results for the decays of the scalar particles to low mass ( 20 GeV) particles with lifetimes in the range 10 c[tau]
Download or read book Searches for a Heavy Scalar Boson mathrm H Decaying to a Pair of 125 GeV Higgs Bosons mathrm Hh Or for a Heavy Pseudoscalar Boson mathrm A Decaying to mathrm Zh in the Final States with mathrm h to tau tau written by and published by . This book was released on 2015 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Physics Associated with Neutrino Masses written by Diego Aristizabal Sierra and published by Frontiers Media SA. This book was released on 2020-01-13 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.
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 the Third generation Scalar Leptoquarks and Heavy Right handed Neutrinos in Final States with Two Tau Leptons and Two Jets in Proton proton Collisions at sqrt s written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A search is performed for third-generation scalar leptoquarks and heavy right-handed neutrinos in events containing one electron or muon, one hadronically decaying tau lepton, and at least two jets, using a $\sqrt{s}$=13 TeV pp collision data sample corresponding to an integrated luminosity of 12.9 inverse femtobarns collected with the CMS detector at the LHC in 2016. The number of observed events is found to be in agreement with the standard model prediction. A limit is set at 95% confidence level on the product of the leptoquark pair production cross section and beta squared where beta is the branching fraction of leptoquark decay to a tau lepton and a bottom quark. Assuming beta=1, third-generation leptoquarks with masses below 850 GeV are excluded at 95 % confidence level. An additional search based on the same event topology involves heavy right-handed neutrinos, N[R], and right-handed W bosons, W[R], arising in a left-right symmetric extension of the standard model. In this search, W[R] bosons are assumed to decay to a tau lepton and N[R] followed by the decay of the N[R] to a tau lepton and an off-shell W[R] boson. Assuming the mass of the right-handed neutrino to be half of the mass of the right-handed W boson, W[R] boson masses below 2.9 TeV are excluded at 95 % confidence level. These results improve on the limits from previous searches for third-generation leptoquarks and heavy right-handed neutrinos with tau leptons in the final state.
Download or read book A Search for Charged Higgs Boson Decays of the Top Quark Using Hadronic Decays of the Tau Lepton in Proton antiproton Collisions at Square Root S written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Standard Model predicts the existence of one neutral scalar Higgs boson, which is a remnant of the mechanism that breaks the SU(2)[sub L]xU(1)[sub Y] electroweak symmetry and generates masses for the heavy vector bosons and fermions. Many extensions to the Standard Model predict two or more Higgs doublets, resulting in a larger spectrum of Higgs bosons including a charged Higgs boson (H[sup [+-]]). For a light charged Higgs boson mass, the top decay into a charged Higgs boson and bottom quark might occur. This thesis presents results of a direct search for this top quark decay mode via the charged Higgs decay to a tau lepton and tau-neutrino, using the hadronic decays of the tau leptons. The search data consist of 100 pb[sup -1] of Run 1 data collected between 1992-1995 at the CDF detector, from p[anti p] collisions at a center-of-mass energy of 1.8 TeV produced at Fermilab's Tevatron accelerator. A total of seven events are observed in two search channels with an expected background contribution of 7.4[+-]2.0 events coming from fake taus (5.4[+-]1.5), heavy vector boson decays with jets (1.9[+-]1.3) and dibosons(0.08[+-]0.06). Lacking evidence for a signal, we set limits on charged Higgs production at the 95% confidence level in the charged Higgs mass plane versus tan[beta](a parameter of the theory) for a top quark mass of 175 GeV/c[sup 2] and for top production cross sections ([sigma][sub t[anti t]]) of 5.0 and 7.5 pb, assuming the Type-II Two-Higgs-Doublet-Model. For large tan[beta], this analysis excludes a charged Higgs boson of mass below 147(158)GeV/c[sup 2] for [sigma][sub t[anti t]]=5.0(7.5)pb. Using the Standard Model measured top quark cross section from CDF, this limit increases to 168 GeV/c[sup 2] and we also exclude a branching fraction of top decays via this charged Higgs mode of greater than 43% for charged Higgs masses below 168 GeV/c[sup 2].
Download or read book Lepton Photon Interactions At High Energies Lepton Photon 2017 Proceedings Of The 28th International Symposium written by Wang Wei and published by World Scientific. This book was released on 2020-02-27 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: The latest of the 'Lepton Photon' symposium, one of the well-established series of meetings in the high-energy physics community, was successfully organized at the South Campus of Sun Yat-sen University, Guangzhou, China, from August 7-12, 2017, where physicists around the world gathered to discuss the latest advancements in the research field.This proceedings volume of the Lepton Photon 2017 collects contributions by the plenary session speakers and the posters' presenters, which cover the latest results in particle physics, nuclear physics, astrophysics, cosmology, and plans for future facilities.
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 Lepton flavor VViolation in Z boson Decays with tau Leptons with the ATLAS Detector written by ATLAS Collaboration CERN and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cracking the Quantum Code of the Universe written by John Moffat and published by Oxford University Press. This book was released on 2014-02 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: If the new boson is indeed the Higgs particle, its discovery represents an important milestone in the history of particle physics. However, despite the pressure to award Nobel Prizes to physicists associated with the Higgs boson, John Moffat argues that there still remain important data analyses to be performed before uncorking the champagne. John Moffat is Professor Emeritus of Physics at the University of Toronto and a senior researcher at the Perimeter Institute for Theoretical Physics. Well-known for his outside-the-box research on topics such as dark matter, dark energy, and the varying speed of light cosmology (VSL), his new book takes a critical look at the hype surrounding the Higgs boson. In the process, he presents a cogent and often entertaining history of particle physics and an exploration of alternative theories of particle physics that do not feature the Higgs boson, including his own. He gives a detailed and personal description of how theoretical physicists come up with new theories, and emphasizes how carefully experimental physicists must interpret the complex data now coming out of accelerators like the Large Hadron Collider (LHC). The book does not shy away from controversial topics such as the sociology of particle physics. There is immense pressure on projects like the $9 billion LHC to come up with positive results in order to secure funding for the future. Yet to date, the Higgs boson may be the only positive result to emerge from the LHC experiments. The searches for dark matter particles, mini-black holes, extra dimensions, and supersymmetric particles have all come up empty-handed, with serious consequences for theoretical physics, including string theory and gravity theory. John Moffat is also the author of Reinventing Gravity (2008) and Einstein Wrote Back (2010).
Download or read book Search for Higgs Boson Pair Production in the bb Decay Channel written by Luca Cadamuro and published by Springer. This book was released on 2018-12-06 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents innovative contributions to the CMS experiment in the new trigger system for the restart of the LHC collisions in Run II, as well as original analysis methods and important results that led to official publications of the Collaboration. The author's novel reconstruction algorithms, deployed on the Field-Programmable Gate Arrays of the new CMS trigger architecture, have brought a gain of over a factor 2 in efficiency for the identification of tau leptons, with a very significant impact on important H boson measurements, such as its decays to tau lepton pairs and the search for H boson pair production. He also describes a novel analysis of HH → bb tautau, a high priority physics topic in a difficult channel. The original strategy, optimisation of event categories, and the control of the background have made the result one of the most sensitive concerning the self-coupling of the Higgs boson among all possible channels at the LHC.
Download or read book The Higgs Hunter s Guide written by John F. Gunion and published by CRC Press. This book was released on 2018-03-05 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Higgs Hunter's Guide is a definitive and comprehensive guide to the physics of Higgs bosons. In particular, it discusses the extended Higgs sectors required by those recent theoretical approaches that go beyond the Standard Model, including supersymmetry and superstring-inspired models.
Download or read book Joint International Lepton photon Symposium And Europhysics Conference On High Energy Physics Lp hep 91 In 2 Volumes written by Seamus Hegarty and published by World Scientific. This book was released on 1992-05-26 with total page 1432 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proceedings of the Joint International Lepton-Photon Symposium and Europhysics Conference on High Energy Physics cover the full range of frontline research in high energy particle physics. The latest results, both theoretical and experimental, are presented and reviews of recent developments in instrumentation and accelerator techniques are included.Volume one summarises the highly specialised topics presented in the parallel sessions while the second volume contains the review talks given by the invited speakers.
Download or read book Study of Z Boson Decays Into Pairs of Muon and Tau Leptons with the CMS Detector at the LHC written by Manuel Zeise and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
