Results from the high-energy, high-statistics studies of neutrino nucleon interactions by the CCFR collaboration at the Fermilab Tevatron are described. Using a data sample of over 3.7 million events ...with energies up to 600 GeV, precision measurements are presented for the weak mixing angle, sin
2
θ
w
, the structure functions, F
2(
χ, Q
2) and
χF
3(
χ, Q
2), and the strange quark distribution,
χs(
χ, Q
2). Comparisons of these measurements to those obtained in other processes are made in the context of global electroweak and QCD tests. Prospects for the next generation measurements by the NuTeV collaboration at Fermilab are also presented.
A high-statistics study by the Columbia-Chicago-Fermilab-Rochester Collaboration of opposite-sign dimuon events induced by neutrino-nucleon scattering at the Fermilab Tevatron is presented. A sample ...of 5044 nusub mu and 1062 bar nusub mu induced musup minus plusmusup plus minus events with ital Psub mu1ge9 GeV/ital c, ital Psub mu2ge5 GeV/ital c, 30leital Esub nule600 GeV, and l angleital Qsup 2r angle=22.2 GeVsup 2/ital csup 2 is observed. The data support the slow-rescaling model of charm production with a value of ital msub ital c=1.31plus minus0.24 GeVsup 2/ital csup 2. The first measurement of the ital Qsup 2 dependence of the nucleon strange quark distribution ital xs(ital x) is presented. The data yield the Cabibbo-Kobayashi-Maskawa matrix element vert barital Vsub ital cital dvert bar=0.209plus minus0.012 and the nucleon fractional strangeness content etasub ital s=0.064sub minus0.007sup +0.008.
The CMS Global Calorimeter Trigger (GCT) is the device within the Level-1 CMS calorimeter trigger system which is assigned the tasks of finding and sorting forward, central and tau-jet candidates, ...sorting isolated and non-isolated electron candidates and reading out all of the calorimeter trigger data. The GCT system has been installed and commissioned in the CMS underground cavern. A sophisticated software package has been developed for controlling and configuring the GCT hardware and monitoring the GCT status. Over the past two years the GCT system has undergone detailed testing and its performance is well understood. The GCT design provides for buffers at the inputs to the GCT which have been used to inject energy depositions corresponding to electrons and jets and test the GCT functionality by comparing the GCT output with that of simulation. Monte Carlo events simulating the decay of Higgs particles and other processes have been used to validate the performance of the GCT. The GCT has also been commissioned with the other components of the Level-1 trigger chain in cosmicray muon runs. Results from these studies are presented.
QCD in the photon structure at HERA Foudas, Constantinos
Nuclear physics. Section B, Proceedings supplement,
03/1999, Letnik:
74, Številka:
1
Journal Article
Studies of the structure of real and virtual photons provide an important test for QCD. At HERA the photon structure is probed via jet production in photon-photon collisions. In this article we ...review the status of the current measurements on photon structure at HERA.
The CMS Level-1 calorimeter trigger is being upgraded in two stages to maintain performance as the LHC increases pile-up and instantaneous luminosity in its second run. In the first stage, improved ...algorithms including event-by-event pile-up corrections are used. New algorithms for heavy ion running have also been developed. In the second stage, higher granularity inputs and a time-multiplexed approach allow for improved position and energy resolution. Data processing in both stages of the upgrade is performed with new, Xilinx Virtex-7 based AMC cards.
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