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 A Measurement of the W Boson Mass in Proton antiproton Collisions at a Center of Mass Energy of 1 8 TeV written by Eric Michael Flattum and published by . This book was released on 1996 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 New Heavy Charged Bosons and Measurement of High Mass Drell Yan Production in Proton Proton Collisions written by Markus Zinser and published by Springer. This book was released on 2018-09-25 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents two analyses, the first of which involves the search for a new heavy charged gauge boson, a so-called W' boson. This new gauge boson is predicted by some theories extending the Standard Model gauge group to solve some of its conceptual problems. Decays of the W' boson in final states with a lepton (l± = e± , μ±) and the corresponding (anti-)neutrino are considered. Data collected by the ATLAS experiment in 2015 at a center of mass energy of √s =13 TeV is used for the analysis. In turn, the second analysis presents a measurement of the double-differential cross section of the process pp->Z/gamma^* + X -> l^+l^- + X, including a gamma gamma induced contribution, at a center of mass energy of sqrt{s} = 8 TeV. The measurement is performed in an invariant mass region of 116 GeV to 1500 GeV as a function of invariant mass and absolute rapidity of the l^+l^-- pair, and as a function of invariant mass and pseudorapidity separation of the l^+l^-- pair. The data analyzed was recorded by the ATLAS experiment in 2012 and corresponds to an integrated luminosity of 20.3/fb. It is expected that the measured cross sections are sensitive to the PDFs at very high values of the Bjorken-x scaling variable, and to the photon structure of the proton.
Download or read book New Aspects of High Energy Proton Proton Collisions written by A. Ali and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Articles focus on the planned European proton-proton collider, and concentrate on physics issues, rather than the more technical concerns addressed in the three previous workshops. The use of energies much higher than those of the American Superconducting Super Collider is featured. Topics include reviews of current projects, hadron collisions, lep
Download or read book High Pt Physics at Hadron Colliders written by Dan Green and published by Cambridge University Press. This book was released on 2005 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher Description
Download or read book Medium Energy Antiprotons and the Quark Gluon Structure of Hadrons written by R. Klapisch and published by Springer. This book was released on 2012-01-31 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fourth course of the International School on Physics with Low Energy Antiprotons was held in Erice, Sicily, at the Ettore Majorana Centre for Scientific Culture from 25 to 31 January, 1990. The previous courses covered topics related to fundamental symmetries, light and heavy quark spectroscopy, and antiproton-nucleus interactions. The purpose of this school is to review theoretical and experimental aspects of low energy antiproton physics concerning the quark-gluon structure of hadrons and the dynamics of the. antiproton-nucleon interaction. Another important objective is the discussion of future directions of research with low-and medium-energy antiprotons in the context of future medium energy facilities at CERN and elsewhere. These proceedings contain both the tutorial lectures and the various contributions presented during the school by the participants. The proceedings have been organised in three sections. The first section is devoted to the theoretical lectures and contributions. The selection of the various subjects wants to emphasize the correlation between antiproton-nucleon physics and the underlying description in terms of quarks and gluons. The second section contains an overview about 35 years of experiments with antiprotons. It gives an introduction to the particle physics aspects of the field by outlining the historical development of experiment and theory, and by describing the motivation and the results of three recent LEAR experiments in more detail. The third section contains most of the contributions of the participants describing in more detail certain aspects of current or planned experiments at LEAR.
Download or read book Antiproton Proton Physics and the W Discovery written by J. Thanh Van Tran and published by Atlantica Séguier Frontières. This book was released on 1983 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Associated Production of W Charm in 13 TeV Proton Proton Collisions Measured with CMS and Determination of the Strange Quark Content of the Proton written by Svenja Karen Pflitsch and published by Springer Nature. This book was released on 2020-08-18 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The associated production of a W boson and a single charm quark (W+c) is the only process in proton-proton collisions that directly probes the strange quark content of the proton. In this thesis, W+charm production is measured in proton-proton collisions at the LHC at 13 TeV, as recorded by the Compact Muon Solenoid (CMS) experiment. The analysis focuses on the identification of W bosons in their leptonic decay to a muon and a neutrino and charm quarks are tagged via the full reconstruction of D*-Mesons. The measured cross sections of W+c production are used, in combination with other relevant CMS results and the most precise HERA DIS data, in a QCD analysis to determine the strange quark content of the proton. The resulting strange quark distribution and suppression, with respect to the other light sea quarks, are in good agreement with those obtained in neutrino scattering experiments and extend their kinematic reach.
Download or read book Search for Charginos Nearly Mass Degenerate with the Lightest Neutralino written by Shingo Kazama and published by Springer. This book was released on 2015-10-22 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, the anomaly mediated supersymmetry breaking (AMSB) model is explored by searching for charged winos with their subsequent decays collected with the ATLAS detector at the Large Hadron Collider (LHC). The author develops a new method, called “re-tracking,” to detect charged winos that decay before reaching the Semiconductor Tracker (SCT) detector. Because the nominal tracking algorithm at the ATLAS experiment requires at least seven successive hits in the inner tracking system, the sensitivity to charged winos having a fraction of a nanosecond in the past analysis was therefore limited. However, re-tracking requires a minimum of three pixel hits and provides a fully efficient tracking capability for charged winos traversing the pixel detector, resulting in around about 100 times greater efficiency for charged winos with a lifetime ~0.2 ns longer than that in past searches. Signal topology is characterized by a jet with large transverse momentum (pT), large missing transverse energy, and a high-pT disappearing track. There are three types of back ground tracks: interacting hadron tracks, charged leptons, and tracks with mismeasured pT. A background estimation based on the Monte Carlo (MC) simulation suffers from large uncertainties due to poor statistics and has difficulty simulating the properties of background tracks. Therefore, a data-driven approach has been developed by the author of the book to estimate the background track-pT spectrum. No significant excess above the background expectation is observed for candidate tracks with large transverse momentum, and constraints on the AMSB model are obtained. The author shows that in the AMSB model, a charged wino mass below 270 GeV is excluded at 95 % confidence level, which also directly constrains the mass of wino dark matter.
Download or read book A Study of the Annihilations of Antiprotons at Rest in Hydrogen Into Three Neutral Pions written by Thomas Kozlowski and published by . This book was released on 1971 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pion Kaon Proton and Antiproton Production in Proton Proton Collisions written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-22 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inclusive pion, kaon, proton, and antiproton production from proton-proton collisions is studied at a variety of proton energies. Various available parameterizations of Lorentz-invariant differential cross sections as a function of transverse momentum and rapidity are compared with experimental data. The Badhwar and Alper parameterizations are moderately satisfactory for charged pion production. The Badhwar parameterization provides the best fit for charged kaon production. For proton production, the Alper parameterization is best, and for antiproton production the Carey parameterization works best. However, no parameterization is able to fully account for all the data. Norbury, John W. and Blattnig, Steve R. Langley Research Center ANTIPROTONS; KAONS; PROTON ENERGY; SCATTERING CROSS SECTIONS; PIONS; PARAMETERIZATION; TRANSVERSE MOMENTUM
Download or read book Hadron Production by E e Annihilation at Center of mass Energies Between 2 6 and 7 8 GeV written by James Leon Siegrist and published by . This book was released on 1979 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Searches for Dijet Resonances written by Lydia Audrey Beresford and published by Springer. This book was released on 2018-09-14 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses one of the most intriguing mysteries of our universe: the nature of dark matter. The results presented here mark a significant and substantial contribution to the search for new physics, in particular for new particles that couple to dark matter. The first analysis presented is a search for heavy new particles that decay into pairs of hadronic jets (dijets). This pioneering analysis explores unprecedented dijet invariant masses, reaching nearly 7 TeV, and sets constraints on several important new physics models. The two subsequent analyses focus on the difficult low dijet mass region, down to 200 GeV, and employ a novel technique to efficiently gather low-mass dijet events. The results of these analyses transcend the long-standing constraints on dark matter mediator particles set by several existing experiments.
Download or read book Charged Kaon and Proton Production in B hadron Decays written by Fredrik Tegenfeldt and published by . This book was released on 2001 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Some Consequences of Possible Quadratic Intermidiate Vector Boson Interactions with Hadrons written by Stephen V. Pepper and published by . This book was released on 1964 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The First Measurement of the Differential Cross section of Electroweak W plus minus W plus minus jj Production at 13 TeV with the ATLAS Detector written by Shalu Solomon and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Vector boson scattering is one of the recent remarkable observations at the Large Hadron Collider. The longitudinal polarization modes of the massive vector bosons are strongly tied to the electroweak symmetry breaking mechanism. With the Standard Model predicted Higgs boson playing a crucial role in regularizing the scattering amplitude of these longitudinally polarized bosons, vector boson scattering is a pivotal process in experimentally probing the symmetry breaking mechanism. A golden channel for measuring vector boson scattering at the collider is the electroweak production of two $W$ bosons with the same electric charges. Owing to its largest quark- to gluon- induced production ratio among other di-boson combinations, the process was also the first target of the ATLAS vector boson scattering program, with evidence made in 2014 and observation in 2019. This thesis presents the first measurement of the differential cross-section with the ATLAS experiment at $\sqrt{s}=13$\,TeV using 139\,fb$^{-1}$ datasets of proton-proton collisions. The process is studied in the leptonic decay channels of the $W$ bosons, effectively suppressing many Standard Model backgrounds. The process $pp \rightarrow l^{\pm} \nu l^{\pm} \nu jj $ is measured with the final state consisting of two leptons of like charges, two jets, and missing transverse energy. The characteristic vector boson scattering signature of two tagging jets, with a large di-jet invariant mass, separated by large angles, is used to tag electroweak-induced production. A combination of Monte Carlo-based predictions and data-driven approaches is used to estimate the various backgrounds. A statistical model of profile likelihood is used to constrain the background predictions and reduce the uncertainties following which the events are unfolded, and the cross-section is extracted. The fiducial differential cross-sections are measured in the leptonic channel as a function of several kinematic variables and are found to be consistent with the Standard Model predictions within uncertainties. An experimental precision of 10.2\% is achieved for the fiducial cross-section, and the measurement is unprecedented in precision and granularity for the process. The integrated fiducial cross-section is $3.51 \pm 0.27\,\text{(stat)}\,\pm 0.23\,\text{(syst)}\,\text{fb}$ and agrees with the leading order prediction of $2.97^{+0.28}_{-0.24}\,\text{fb} $ simulated by MadGraph+Herwig7 within uncertainties
