4,359 research outputs found
Top Quark Mass Measurements at the Tevatron
The general strategy, as well as channel-specific details, applied to the
measurement of the top quark mass at the Tevatron in Run I are reviewed, and
the combination of the results obtained by the CDF and DO collaborations
presented. The accelerator and detector upgrades for Run II are described, and
expected improvements in the systematic uncertainties on the measurement
evaluated.Comment: Latex (Frascati.sty), 11 pages, 3 figs. Talk given at the 14th
Rencontres de Physique de la Vallee d'Aoste, La Thuile, Aosta Valley, Italy,
February 200
Searches for New Physics at D0
The integrated luminosity at Run 2 of the Tevatron is approaching the Run 1
total, and data analysis is progressing. New results in searches for new
physics by the DO experiment are presented in a variety of channels,
demonstrating good performance of the detector and detailed understanding of
the data.Comment: 6 pages, proceedings of the 38th Rencontres de Morion
Mixing and CP Violation at the Tevatron
Measurements of meson mixing and CP violation parameters obtained by the CDF
and D0 experiments at the Fermilab Tevatron are presented. These include
results on and meson mixing, and searches for CP violation in the
decay , in mixing through semileptonic meson decays,
and in the interference between mixing and decay in the process .Comment: 9 pages, Proceedings of the Hadron Collider Physics Symposium
(HCP2008),Galena, Illinois, US
Determination of Scanning Efficiencies in Experiments Using Nuclear Emulsion Sheets
During their exposure, nuclear emulsion sheets detect both tracks from
experiment-related particles, as well as a considerable amount of background
tracks, mainly due to cosmic rays. Unless the exposure has been fairly short,
it is therefore fairly likely that a fraction of the tracks that have been
identified as belonging to the particles the experiment is interested in, are
really due to background. A method, which allows to measure this fraction
reliably directly from the data, is described.Comment: 7 pages, uses elsart, to be published in NIMA 450, p 44
ATLAS Upgrade Instrumentation in the US
Planned upgrades of the LHC over the next decade should allow the machine to
operate at a center of mass energy of 14 TeV with instantaneous luminosities in
the range 5--7e34 cm^-2 s^-1. With these parameters, ATLAS could collect 3,000
fb^-1 of data in approximately 10 years. However, the conditions under which
this data would be acquired are much harsher than those currently encountered
at the LHC. For example, the number of proton-proton interactions per bunch
crossing will rise from the level of 20--30 per 50 ns crossing observed in 2012
to 140--200 every 25 ns. In order to deepen our understanding of the newly
discovered Higgs boson and to extend our searches for physics beyond that new
particle, the ATLAS detector, trigger, and readout will have to undergo
significant upgrades. In this whitepaper we describe R&D necessary for ATLAS to
continue to run effectively at the highest luminosities foreseen from the LHC.
Emphasis is placed on those R&D efforts in which US institutions are playing a
leading role.Comment: Snowmass contributed paper, 24 pages, 12 figure
A Radiation-Hard Dual Channel 4-bit Pipeline for a 12-bit 40 MS/s ADC Prototype with extended Dynamic Range for the ATLAS Liquid Argon Calorimeter Readout Electronics Upgrade at the CERN LHC
The design of a radiation-hard dual channel 12-bit 40 MS/s pipeline ADC with
extended dynamic range is presented, for use in the readout electronics upgrade
for the ATLAS Liquid Argon Calorimeters at the CERN Large Hadron Collider. The
design consists of two pipeline A/D channels with four Multiplying
Digital-to-Analog Converters with nominal 12-bit resolution each. The design,
fabricated in the IBM 130 nm CMOS process, shows a performance of 68 dB SNDR at
18 MHz for a single channel at 40 MS/s while consuming 55 mW/channel from a 2.5
V supply, and exhibits no performance degradation after irradiation. Various
gain selection algorithms to achieve the extended dynamic range are implemented
and tested.Comment: 22 pages, 22 figures, accepted by JINS
High pT Hadronic Top Quark Identification
At the LHC objects with masses at the electroweak scale will for the first time be produced with very large transverse momenta. In many cases, these objects decay hadronically, producing a set of collimated jets. This interesting new experimental phenomenology requires the development and tuning of new tools, since the usual reconstruction methods would simply reconstruct a single jet. This note describes the application of the YSplitter algorithm in conjunction with the jet mass to identify high transverse momentum top quarks decaying hadronically
Specific separation- and detection strategies for the characterization of acid-functional polymers
A Supersymmetric Solution to the Solar and Atmospheric Neutrino Anomalies
The formalism for neutrino flavor change induced by lepton family number
violating interactions is developed for the three-neutrino case, and used to
derive the corresponding flavor change probabilities in matter. Applied to the
solar and atmospheric neutrino fluxes, it is argued that the observed
anomalies, including the zenith dependence for the atmospheric case, could be
due to such interactions.Comment: 6 pages, 1 figure Modifications: include limit from tau -> rho mu
(leads to somewhat different conclusions) and a change to the figur
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