Tau Jet Signals for Supersymmetry at the Tevatron
Tau Jet Signals for Supersymmetry at the Tevatron

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Published: 2000

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The authors present a more detailed account of the study (hep-ph/9903238) for the supersymmetry reach of the Tevatron in channels with isolated leptons and identified tau jets. They review the theoretical motivations for expecting such signatures, and describe the relevant parameter space in the minimal supergravity and the minimal gauge-mediated models. With explicit Monte Carlo simulations they then show that for certain parameter ranges, channels with two leptons and one tau jet offer a better reach in Run 2 than the clean trilepton signal. They emphasize that improving on tau ID is an important prerequisite for successful searches in multiple tau jet channels. Finally, they discuss some triggering issues.

Heavy Octets and Tevatron Signals with Three Or Four B Jets
Heavy Octets and Tevatron Signals with Three Or Four B Jets

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Published: 2011

Total Pages: 33

ISBN-13:

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Hypothetical color-octet particles of spin 0, pair-produced at hadron colliders through their QCD coupling, may lead to final states involving three or four b jets. We analyze kinematic distributions of the 3b final state that differentiate the scalar octets from supersymmetric Higgs bosons. Studying the scalar sector that breaks an SU(3) x SU(3) gauge symmetry down to the QCD gauge group, we find that the scalar octet is resonantly produced in pairs via a spin-1 octet (coloron). A scalar octet of mass in the 140-150 GeV range can explain the nonstandard shape of the b-jet transverse energy distributions reported by the CDF Collaboration, especially when the coloron mass is slightly above twice the scalar mass. The dominant decay mode of the scalar octet is into a pair of gluons, so that the production of a pair of dijet resonances is large in this model, of about 40 pb at the Tevatron. Even when a W boson is radiated from the initial state, the inclusive cross section for producing a dijet resonance near the scalar octet mass remains sizable, around 0.15 pb.

Supersymmetry and the Unification of Fundamental Interactions
Supersymmetry and the Unification of Fundamental Interactions

Author: Deog Ki Hong

Publisher: AIP Conference Proceedings (Nu

Published: 2008-12-11

Total Pages: 670

ISBN-13:

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This annual SUSY conference has become the world's largest international meeting devolted to new ideas in high energy physics. The main subject of the conference is theoretical and phenomenological aspects of supersymmetric theories, and dark matter and dark energy, and other comological connections. New, interesting results from various experimental groups are increasingly presented at the conference as well. With roughly 200 plenary and parallel presentations, SUSY08 will likely deliver energy and enthusiasm of both theorists and experimentalists who are searching the frontier of high energy physics.

Top Quark Physics at Hadron Colliders
Top Quark Physics at Hadron Colliders

Author: Arnulf Quadt

Publisher: Springer Science & Business Media

Published: 2007-08-16

Total Pages: 166

ISBN-13: 3540710604

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This will be a required acquisition text for academic libraries. More than ten years after its discovery, still relatively little is known about the top quark, the heaviest known elementary particle. This extensive survey summarizes and reviews top-quark physics based on the precision measurements at the Fermilab Tevatron Collider, as well as examining in detail the sensitivity of these experiments to new physics. Finally, the author provides an overview of top quark physics at the Large Hadron Collider.

Measurement of Sigma(p Anti-p -] T Anti-t) in the Tau + Jets Channel by the Dï¿1/2 Experiment at Run II of the Tevatron Collider
Measurement of Sigma(p Anti-p -] T Anti-t) in the Tau + Jets Channel by the Dï¿1/2 Experiment at Run II of the Tevatron Collider

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Published: 2008

Total Pages: 135

ISBN-13:

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The top quark is the heaviest and most mysterious of the known elementary particles. Therefore, careful study of its production rate and other properties is of utmost importance for modern particle physics. The Tevatron is the only facility currently capable of studying top quark properties by on-shell production. Measurement of the top quark pair production cross section is one of the major goals of the Tevatron Run II physics program. It provides an excellent test of QCD at energies exceeding 100 GeV. We report on a new measurement of p{bar p} → t{bar t} production at √ = 1.96 TeV using 350 pb−1 of data collected with the D0 detector between 2002 and 2005. We focus on the final state where a W boson from one of the top quarks decays into a [tau] lepton and its associated neutrino, while the other decays into a quark-antiquark pair. We aim to select those events in which the [tau] lepton subsequently decays to one or three charged hadrons, zero or more neutral hadrons and a tau neutrino (the charge conjugate processes are implied in all of the above). The observable signature thus consists of a narrow calorimeter shower with associated track(s) characteristic of a hadronic tau decay, four or more jets, of which two are initiated by b quarks accompanying the W's in the top quark decays, and a large net missing momentum in the transverse plane due to the energetic neutrino-antineutrino pair that leave no trace in the detector media. The preliminary result for the measured cross section is: [sigma](t{bar t}) = 5.1{sub -3.5}{sup +4.3}(stat){sub -0.7}{sup +0.7}(syst) ± 0.3 (lumi.) pb.