Download or read book Search for Resonant Pair Production of Long lived Particles Decaying to B Anti b in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2009 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on a first search for production of Higgs bosons decaying into neutral long-lived particles (NLLP) which each decay to a b{bar b} pair, using 3.6 fb−1 of data recorded with the D0 detector at the Fermilab Tevatron collider. We search for pairs of displaced vertices in the tracking detector at radii in the range 1.6-20 cm from the beam axis. No significant excess is observed above background, and upper limits are set on the production rate in a hidden-valley benchmark model for a range of Higgs boson masses and NLLP masses and lifetimes.

Download or read book Search Strategies for New Physics at the LHC written by Daniele Spier Moreira Alves and published by Stanford University. This book was released on 2011 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: The LHC is in the frontline of experimental searches for New Physics beyond the Standard Model of Particle Physics. Its power is accompanied by no smaller challenges in analyzing and interpreting its results. In this thesis I explore ways to parameterize new physics phenomena, design search strategies that are sensitive to them, and interpret experimental results in general new physics contexts. In particular, I discuss interpretations of the first ATLAS analysis for supersymmetry with 70/nb of integrated luminosity. I also carry a careful investigation of comprehensive search strategies for new physics with jets and missing energy signatures, and estimate the sensitivity bounds of the 7 TeV LHC to new colored particles decaying to jets and and a neutral particle that escapes detection. Finally, I discuss the implications of the recent LHC excesses hinting to a Higgs boson with mass in the range 142-147 GeV. If confirmed, this range for the Higgs mass will be an important evidence for Split Supersymmetry. I work out the phenomenological predictions of this scenario that will be tested in the very near future by a variety of experiments, including direct and indirect dark matter detection, EDM experiments searching for CP violation and the 7 TeV run of the LHC.

Download or read book High Energy Physics Index written by and published by . This book was released on 1990 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for New High Mass Particles Decaying to Lepton Pairs in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2005 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for the Decays of Stopped Exotic Long lived Particles Produced in P P Collisions at 13 TeV at CMS written by Weifeng Ji and published by . This book was released on 2018 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, I present the searches looking for decays of stopped massive long-lived exotic particles, which are pair produced in the proton-proton collisions at 13 TeV and come to rest afterwards in the CMS detector at the CERN LHC. The decays are most likely to be observed when there are no collisions. Two specific decay scenarios are studied: a long-lived particle (LLP) decaying hadronically or semi- leptonically in the calorimeter, and a LLP decaying semi-leptonically or leptonically to a pair of muons in the muon detector. The calorimeter-based search is performed using 2.7 fb-1 of 13 TeV collision run data collected in 2015 and 35.9 fb-1 of 13 TeV collision run data collected in 2016, corresponding to a total trigger livetime of 721 hours. The muon search is performed using 2.8 fb-1 of 13 TeV collision run data collected in 2015 and 36.2 fb-1 of 13 TeV collision run data collected in 2016, corresponding to a total trigger livetime of 744 hours. Search results are interpreted in a couple of simplified models. The limits on the production cross sections and masses of LLPs are calculated as a function of particle lifetimes, which vary from 100 ns to 10 days, assuming the corresponding decaying branching fractions to be 100%. The results are the most stringent ones on the stopped LLPs so far.

Download or read book INIS Atomindeks written by and published by . This book was released on 1988 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for Resonant T Anti t Production in P Anti p Collisions at S written by and published by . This book was released on 2007 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on a search for narrow-width particles decaying to a top and antitop quark pair. The data set used in the analysis corresponds to an integrated luminosity of 680 pb−1 collected with the Collider Detector at Fermilab in Run II. We present 95% confidence level upper limits on the cross section times branching ratio. Assuming a specific top color-assisted technicolor production model, the leptophobic Z′ with width?{sub Z{prime}} = 0.012M{sub Z{prime}}, we exclude the mass range M{sub Z{prime}}

Download or read book Search for Long lived Resonance Decaying to a Dilepton Pair in Pp Collisions at square Root of S written by Siinn Che and published by . This book was released on 2018 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for Heavy Long lived Particles that Decay to Photons in Ppbar Collisions at Sqrt s written by Peter Wagner and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents the results of the first search for heavy, neutral, longlived particles that decay to photons at a hadron collider. We use a sample of +jet+missing transverse energy events in pp̄ collisions at s = 1.96 TEV taken with the Collider Detector at Fermilab. Candidate events are selected based on the arrival time of a high-energy photon at the electromagnetic calorimeter as measured with a timing system that was recently installed. The final result is that we find 2 events, using 570"34 pb−1 of data collected during 2004-2005 at the Fermilab Tevatron, consistent with the background estimate of 1.3"0.7 events.

Download or read book Search for Pair Production of Strongly Interacting Particles Decaying to Pairs of Jets in p bar p Collisions at sqrt s written by and published by . This book was released on 2013 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1987 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for Decays of Stopped Long lived Particles Produced in Proton proton Collisions at arrow written by and published by . This book was released on 2015 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for Stable and Long lived Heavy Charged Particles in Electron positron Collisions at Center of Mass Energies from 130 to 209 GeV with the OPAL Detector at LEP written by Gabriele Benelli and published by . This book was released on 2003 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Search for R parity Violating Supersymmetry with Displaced Vertices 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: Results are reported from a search for R-parity violating supersymmetry in proton-proton collision events collected by the CMS experiment at a center-of-mass energy of sqrt(s)=8 TeV. The data sample corresponds to an integrated luminosity of 17.6 inverse femtobarns. This search assumes a minimal flavor violating model in which the lightest supersymmetric particle is a long-lived neutralino or gluino, leading to a signal with jets emanating from displaced vertices. In a sample of events with two displaced vertices, no excess yield above the expectation from standard model processes is observed, and limits are placed on the pair production cross section as a function of mass and lifetime of the neutralino or gluino. At 95% confidence level, the analysis excludes cross sections above approximately 1 fb for neutralinos or gluinos with mass between 400 and 1500 GeV and mean proper decay length between 1 and 30 mm. Assuming gluino pair production cross sections, gluino masses are excluded below 1 and 1.3 TeV for mean proper decay lengths of 300 micrometers and 1 mm, respectively, and below 1.4 TeV for the range 2-30 mm. The results are also applicable to other models in which long-lived particles decay into multijet final states.

Download or read book A Search for Resonant Production of t bar t Pairs in 4 8 rm fb 1 of Integrated Luminosity of p bar p Collisions at sqrt s written by and published by . This book was released on 2011 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: We search for resonant production of t{bar t} pairs in 4.8 fb−1 integrated luminosity of p{bar p} collision data at √s = 1.96 TeV in the lepton+jets decay channel, where one top quark decays leptonically and the other hadronically. A matrix element reconstruction technique is used; for each event a probability density function (pdf) of the t{bar t} candidate invariant mass is sampled. These pdfs are used to construct a likelihood function, whereby the cross section for resonant t{bar t} production is estimated, given a hypothetical resonance mass and width. The data indicate no evidence of resonant production of t{bar t} pairs. A benchmark model of leptophobic Z' → t{bar t} is excluded with m{sub Z'}

Download or read book Search for the Production of Narrow T Anti b Resonances in 1 9 Fb 1 of P Anti p Collisions at S written by and published by . This book was released on 2009 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present new limits on resonant tb production in ppbar collisions at sqrt(s) = 1.96 TeV, using 1.9 fb−1 of data recorded with the CDF II detector at the Fermilab Tevatron. We reconstruct a putative tb mass in events with a lepton, neutrino candidate, and two or three jets, and search for anomalous tb production as modeled by W′ → tb. We set a new limit on a right-handed W′ with standard model-like coupling, excluding any mass below 800 GeV at 95% C.L. For any narrow W′-like state with mass above 800 GeV, the cross-section is found to be less than 0.28 pb at 95% C.L. We also present an exclusion of the W′ coupling strength versus W′ mass.

Download or read book Search for Long lived Particles Using Delayed Photons in Proton proton Collisions at 13 TeV with the CMS Detector written by Kevin Patrick McDermott and published by . This book was released on 2019 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents a search for long-lived particles using delayed photons in proton-proton collisions at sqrt(s) = 13 TeV recorded by the Compact Muon Solenoid (CMS) experiment at the CERN Large Hadron Collider in 2017, corresponding to an integrated luminosity of 41.5 fb^-1. This analysis includes a number of unique components that will be discussed: a dedicated signal trigger, out-of-time photon reconstruction and identification, and a detector time resolution measurement. The results of this search include the combination of a related analysis using data collected in 2016 also at sqrt(s) = 13 TeV, corresponding to a combined integrated luminosity of 77.4 fb^-1. The combined results are interpreted in the context of supersymmetry with gauge-mediated supersymmetry breaking, where the neutralino is long-lived and decays to a photon and a gravitino. Limits are presented as a function of the neutralino proper decay length and mass. For neutralino proper decay lengths of 10^1, 10^2, 10^3, and 10^4 cm, masses up to 320, 525, 360, and 215 GeV are excluded at 95% confidence level, respectively. Additionally, a discussion on a high-performance computing upgrade to CMS, known as mkFit, will be presented. mkFit is an on-going effort to exploit highly parallel computer architectures in vectorizing and parallelizing combinatorial Kalman filter charged particle track reconstruction algorithms. The current physics and computational performance of this project will be discussed.