17,751 research outputs found
New Directions in Data Analysis
In the next decade, high energy physicists will use very sophisticated
equipment to record unprecedented amounts of data in the hope of making major
advances in our understanding of particle phenomena. Some of the signals of new
physics will be small, and the use of advanced analysis techniques will be
crucial for optimizing signal to noise ratio. I will discuss new directions in
data analysis and some novel methods that could prove to be particularly
valuable for finding evidence of any new physics, for improving precision
measurements and for exploring parameter spaces of theoretical models.Comment: 5 pages, 1 Figure, Presented at DPF2000. Proceedings of the American
Physical Society DPF2000 Meeting, Columbus, Ohio, to be published in the
International Journal of Modern Physics
Search for the Top Quark at D0 using Multivariate Methods
We report on the search for the top quark in proton-antiproton collisions at
the Fermilab Tevatron in the di-lepton and lepton+jets channels using
multivariate methods. An H-matrix analysis of the e-mu data corresponding to an
integrated luminosity of about 13.5 pb-1 yields one event with a likelihood to
be a top event (assuming top mass of 180 GeV/c**2) that is 10 times more than
WW and 18 times more than Z -> tau tau. A neural network analysis of e+jets
channel with about 48 pb-1 of data shows an excess of events in the signal
region and yields a cross-section for top-antitop production of 6.7 +/-
2.3(stat.) pb, assuming a top mass of 200 GeV/c**2. A PDE analysis of e+jets
data gives results consistent with the above.Comment: 12 pages, http://d0wop.fnal.gov/d0pubs/ppbar95/pushpa.ps Replaced
because the first submission was problemati
Fermilab Collider Run II: Accelerator Status and Upgrades
Fermilab will continue to maintain its pre-eminent position in the world of
High Energy Physics, with a unique opportunity to make unprecedented studies of
the top quark and major discoveries, until the Large Hadron collider (LHC) at
CERN becomes operational near the end of the decade. Run II is well underway
with major accelerator and detector upgrades since Run I. A program of further
upgrades to the accelerator complex will result in an integrated luminosity of
4-8 fb-1 per experiment, by the year 2009.Comment: 12 pages, 6 figures. To be published in the Proceedings of the 15th
Topical Conference on Hadron Collider Physics, HCP2004, Michigan State
University, East Lansing, MI, June 14-18, 2004 (American Institute of
Physics, NY, 2004
Search for Narrow-Width ttbar Resonances in ppbar Collisions at center of mass energy = 1.8 TeV
We present a preliminary result on a search for narrow-width resonances that
decay into ttbar pairs using 130 pb^{-1} of lepton plus jets data in ppbar
collisions at center of mass energy = 1.8 TeV. No significant deviation from
Standard Model prediction is observed. 95% C.L. upper limits on the production
cross section of the narrow-width resonance times its branching fraction to
ttbar are presented for different resonance masses, M_X. We also exclude the
existence of a leptophobic topcolor particle, X, with M_X < 560 GeV/c^2 for a
width \Gamma_X = 0.012 M_X.Comment: 3 pages, 1 figure; Submitted for proceedings of 5th International
Conference on Quark Confinement and Hadron spectrum, held in Italy, from
11-14 Sep., 200
Strategy for discovering a low-mass Higgs boson at the Fermilab Tevatron
We have studied the potential of the CDF and DZero experiments to discover a
low-mass Standard Model Higgs boson, during Run II, via the processes
-> WH -> , -> ZH ->
and -> ZH ->. We
show that a multivariate analysis using neural networks, that exploits all the
information contained within a set of event variables, leads to a significant
reduction, with respect to {\em any} equivalent conventional analysis, in the
integrated luminosity required to find a Standard Model Higgs boson in the mass
range 90 GeV/c**2 < M_H < 130 GeV/c**2. The luminosity reduction is sufficient
to bring the discovery of the Higgs boson within reach of the Tevatron
experiments, given the anticipated integrated luminosities of Run II, whose
scope has recently been expanded.Comment: 26 pages, 8 figures, 7 tables, to appear in Physical Review D, Minor
fixes and revision
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