115 research outputs found
B Physics and Quarkonia studies with early ATLAS data
Quarkonia and B-Physics are among the first areas to be investigated with the
first data collected by ATLAS. The ATLAS detector at CERN's LHC is preparing to
take data from proton-proton collisions expected to start by the end of 2009.
Investigation of the decay of B-hadrons represents a complementary approach to
direct searches for Physics beyond the Standard Model. Early B-physics data
will provide valuable information on the detector performance, as well as allow
calibration studies in support of new Physics searches. Meaningful quarkonia
studies performed with early data are expected to have the reach to make
authoritative statements about the underlying production mechanism and provide
cross-sections in this new energy regime. We review various aspects of prompt
quarkonium production at the LHC: the accessible ranges in transverse momentum
and pseudo-rapidity, spin alignment of vector states, separation of color octet
and color singlet production mechanism and feasibility of observing radiative
chi_c decaysComment: Proceedings of the Fourth High-Energy Physics International
Conference HEP-MAD 09, Antananarivo, Madagascar, August 21-28, 200
Experimental Studies of Electroweak Physics
Some experimental new Electroweak physics results measured at the LEP/SLD and
the TEVATRON are discussed. The excellent accuracy achieved by the experiments
still yield no significant evidence for deviation from the Standard Model
predictions, or signal to physics beyond the Standard Model. The Higgs particle
still has not been discovered and a low bound is given to its mass.Comment: 10 pages, 5 figures, Invited talk at "Fundemental Particles and
Interactions", Vanderbilt University, Nashville, Tennessee, May 199
Measurements of Hadronic Asymmetries in e+e- Collisions
High precision experimental new electroweak results measured at the four LEP
experiments and the SLD collaboration are discussed. Heavy quark (b b-bar and c
c-bar) forward-backward asymmetries measured at LEP are presented along with
polarized forward-backward and left-right asymmetries measured at SLD. The
results are compared, and the combined averages are used to evaluate the
Standard Model parameters.Comment: 8 Pages, 5 eps files, Presented at the International Europhysics
Conference on High Energy Physics, August 1997, Jerusalem, Israe
ATLAS reach for Quarkonium production and polarization measurements
The ATLAS detector at CERN's LHC is preparing to take data from the first proton-proton collisions expected in the next few months. We report on the analysis of simulated data samples for production of heavy Quarkonium states J/psi and Upsilon, corresponding to an integrated luminosity of 10 pb^-1 with center of mass energy of 14 TeV expected at the early ATLAS data. We review various aspects of prompt Quarkonium production at LHC: the accessible ranges in transverse momentum and pseudorapidity, spin alignment of vector states, separation of color octet and color singlet production mechanism and feasibility of observing radiative decays Xi_c and Xi_b decays. Strategies of various measurements are outlined and methods of separating promptly produced J/psi and Upsilon mesons from various backgrounds are discussed
The use of cluster quality for track fitting in the CSC detector
The new particle accelerators and its experiments create a challenging data
processing environment, characterized by large amount of data where only small
portion of it carry the expected new scientific information. Modern detectors,
such as the Cathode Strip Chamber (CSC), achieve high accuracy of coordinate
measurements (between 50 to 70 microns). However, heavy physical backgrounds
can decrease the accuracy significantly. In the presence of such background,
the charge induced over adjacent CSC strips (cluster) is different from the
ideal Matheison distribution. The traditional least squares method which takes
the same ideal position error for all clusters loses its optimal properties on
contaminated data. A new technique that calculates the cluster quality and uses
it to improve the track fitting results is suggested. The algorithm is applied
on test beam data, and its performance is compared to other fitting methods. It
is shown that the suggested algorithm improves the fitting performance
significantly.Comment: Proceedings of 2006 IEEE NSS, San Diego, California, USA, November
200
Momentum Reconstruction and Triggering in the ATLAS Detector
A neural network solution for a complicated experimental High Energy Physics problem is described. The method is used to reconstruct the momentum and charge of muons produced in collisions of particle in the ATLAS detector. The information used for the reconstruction is limited to the output of the outer layer of the detector, after the muons went through strong and inhomogeneous magnetic field that have bent their trajectory. It is demonstrated that neural network solution is efficient in performing this task. It is shown that this mechanism can be efficient in rapid classification as required in triggering systems of the future particle accelerators. The parallel processing nature of the network makes it relevant for hardware realization in the ATLAS triggering system.A neural network solution for a complicated experimental High Energy Physics problem is described. The method is used to reconstruct the momentum and charge of muons produced in collisions of particle in the ATLAS detector. The information used for the reconstruction is limited to the output of the outer layer of the detector, after the muons went through strong and inhomogeneous magnetic field that have bent their trajectory. It is demonstrated that neural network solution is efficient in performing this task. It is shown that this mechanism can be efficient in rapid classification as required in triggering systems of the future particle accelerators. The parallel processing nature of the network makes it relevant for hardware realization in the ATLAS triggering system.A neural network solution for a complicated experimental High Energy Physics problem is described. The method is used to reconstruct the momentum and charge of muons produced in collision of particles in the ATLAS detector. The information used for the reconstruction is limited to the output of the outer layer of the detector, after the muons went through strong and inhomogeneous magnetic field that have bent their trajectory. It is demonstrated that neural network solution is efficient in performing this task. It is shown that this mechanism can be efficient in rapid classification as required in triggering systems of the future particle accelerators. The parallel processing nature of the network makes it relevant for hardware realization in the ATLAS triggering system
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