503 research outputs found
Scalar and Tensor Couplings in Kaon Decays
In the past few years charged kaon experiments have indicated possible scalar and tensor couplings in semileptonic kaon decays(K --> pi e nu). These couplings, if correct, are not predicted by the Standard Model and may indicate the onset of new physics. We present a summary of the existing data and a new, precision measurement of these couplings in the neutral kaon system based on a 3% subset of the data taken by the KTeV (E799) experiment at Fermilab
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Beam induced backgrounds: CDF experience
We summarize the experiences of the Collider Detector at Fermilab (CDF) experiment in the presence of backgrounds originating from the counter circulating beams in the Fermilab Tevatron. These backgrounds are measured and their sources identified. Finally, we outline the strategies employed to reduce the effects of these backgrounds on the experiment
Channeling and Volume Reflection Based Crystal Collimation of Tevatron Circulating Beam Halo (T-980)
The T980 crystal collimation experiment is underway at the Tevatron to
determine if this technique could increase 980 GeV beam-halo collimation
efficiency at high-energy hadron colliders such as the Tevatron and the LHC.
T980 also studies various crystal types and parameters. The setup has been
substantially enhanced during the Summer 2009 shutdown by installing a new
O-shaped crystal in the horizontal goniometer, as well as adding a vertical
goniometer with two alternating crystals (O-shaped and multi-strip) and
additional beam diagnostics. First measurements with the new system are quite
encouraging, with channeled and volume-reflected beams observed on the
secondary collimators as predicted. Investigation of crystal collimation
efficiencies with crystals in volume reflection and channeling modes are
described in comparison with an amorphous primary collimator. Results on the
system performance are presented for the end-of-store studies and for entire
collider stores. The first investigation of colliding beam collimation
simultaneously using crystals in both the vertical and horizontal plane has
been made in the regime with horizontally channeled and vertically
volume-reflected beams. Planning is underway for significant hardware
improvements during the FY10 summer shutdown and for dedicated studies during
the final year of Tevatron operation and also for a "post-collider beam physics
running" period.Comment: 3 pp. 1st International Particle Accelerator Conference: IPAC'10,
23-28 May 2010: Kyoto, Japa
The NOvA power distribution system
We describe the power distribution systems and grounding schemes built for the near and far detectors of the NOvA long-baseline neutrino experiment. They are used to power the avalanche photodiodes and their thermoelectric coolers, the front-end boards that read out, digitize and time stamp the signals from the avalanche photodiodes, and the data concentrator modules used to receive and format the data from the front-end boards before sending them to a farm of computers used to build the events. The system powers 344, 064 readout channels in the far detector and 20, 192 channels in the near detector
Beam Condition Monitoring with Diamonds at CDF
This report talks Beam Condition Monitoring with Diamonds at CD
Averages of -hadron, -hadron, and -lepton properties as of summer 2014
This article reports world averages of measurements of -hadron,
-hadron, and -lepton properties obtained by the Heavy Flavor Averaging
Group (HFAG) using results available through summer 2014. For the averaging,
common input parameters used in the various analyses are adjusted (rescaled) to
common values, and known correlations are taken into account. The averages
include branching fractions, lifetimes, neutral meson mixing parameters,
violation parameters, parameters of semileptonic decays and CKM matrix
elements.Comment: 436 pages, many figures and tables. Online updates available at
http://www.slac.stanford.edu/xorg/hfag
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