125413811
Heavy quarkonium physics with early ATLAS data
2486196
The certification of ATLAS thin gap chambers produced in Israel and China
Thin gap chambers (TGCs) are used for the muon trigger system in the forward region of the LHC experiment ATLAS. A TGC consists of a plane of closely spaced wires maintained at positive high voltage, sandwiched between resistive grounded cathode planes with an anode wire to cathode plane gap distance smaller than the wire-to-wire spacing. The TGCs are expected to provide a trigger signal within 25 ns of the bunch spacing of the LHC accelerator, with an efficiency exceeding 95%, while exposed to an effective photon and neutron background ranging from 30 to 500 Hz/cm/sup 2/. About 2,500 out of the 3,600 ATLAS TGCs are being produced at the Weizmann institute in Israel, and in Shandong University in China. Once installed in the ATLAS detector the TGCs will be inaccessible. A vigorous production quality control program is therefore implemented at the production sites. Furthermore, after chamber completion, a thorough program of quality assurance is implemented to ensure the efficient performance of the chambers during more than ten years of operation in the LHC high rate environment. This program consists of a detailed mapping of the detector response using cosmic rays, as well as checking the chambers behavior using a high rate radiation source. An aging test performed on five chambers in a serial gas connection is presented. Finally the results of the chamber certification tests performed at CERN before the installation in ATLAS are described.
54495416
System test of the ATLAS muon spectrometer in the H8 beam at the CERN SPS
We describe a system-test of the ATLAS Muon Spectrometer performed at the H8 beam line of the CERN SPS during 2003. The setup includes one barrel tower made of six Monitored Drift Tube chambers equipped with an alignment system and four Resistive Plate Chambers, and one end-cap octant consisting of six end-cap MDT equipped with an alignment system and one triplet and two doublets of Thin Gap Chambers. Many system aspects of the muon spectrometer have been studied with this setup, from the performance of the precision and trigger chambers to the capability to align the precision chambers at the level of a few tens of micrometers and to operate the muon trigger at the crossing frequency of the LHC.
13594197
The cosmic ray hodoscopes for testing thin gap chambers at the Technion and Tel Aviv University
Thin gap chambers (TGCs) are built for the muon trigger chambers in the endcap region of the LHC experiment ATLAS. More than 2500 ATLAS TGCs are being produced at the Weizmann institute in Israel, and in Shandong University in China. Detailed testing of these chambers is performed at the Technion and at the Tel-Aviv University. Two cosmic ray hodoscopes for testing the operation of these detectors were built in Israel. In these hodoscopes the response of the chambers to energetic cosmic ray muons is recorded and analyzed. The hodoscopes measure the exact time and space location of the cosmic ray hit and read out the chambers which are being tested to verify that they produce a corresponding signal within the required time interval. The cosmic ray hodoscopes built at the Technion and at the Tel Aviv University for the test of ATLAS TGCs are described. The mechanical structure, readout electronics, data acquisition and operating scheme are presented. Typical TGC test results are presented and discussed.
118170002
Analysis of the tau polarization and its forward - backward asymmetry on the Z0
This thesis describes a new a measurement of the tau lepton polarization and its forward-backward asymmetry at the Z resonance using the OPAL detector. This measurement is based on analyses of the tau->electron, muon and pion (Kaon) decays from a sample of 30663 tau-pair events collected in the polar angle range of Abs(cos(theta)) =(-13.5+/-2.9+/-2.2)% and the tau polarization forward-backward asymmetry to be AFBpol=(-11.0+/-3.5+/-0.5)% where the first error is statistical and the second systematic. Combining these figures with the OPAL and AFBpol measured with the tau->rho channel we get an average tau polarization, =(-14.9+/-1.9+/-1.3)% and for the asymmetry in the polarization, AFBpol=(-8.9+/-2.2+/-0.9)% . These results are consistent with lepton universality. Combining the two results we obtain for the electroweak mixing angle the value sin^2(theta_W)=0.2331+/-0.0023 within the context of the Standard Model, where the error includes both statistical and systematic uncertainties.
17588777
High-precision measurement of the left-right Z Boson cross-section asymmetry.
We present a measurement of the left-right cross-section asymmetry ( A(LR)) for Z boson production by e(+)e(-) collisions. The measurement includes the final data taken with the SLD detector at the SLAC Linear Collider during the period 1996-1998. Using a sample of 383 487 Z decays collected during the 1996-1998 runs we measure the pole value of the asymmetry, A(0)(LR), to be 0.150 56+/-0.002 39 which is equivalent to an effective weak mixing angle of sin (2)straight theta(eff)(W) = 0.231 07+/-0.000 30. Our result for the complete 1992-1998 data set comprising approximately 537 000 Z decays is sin (2)straight theta(eff)(W) = 0.230 97+/-0.000 27.
12785495
The Detection of Ionizing Radiation by Plasma Panel Sensors: Cosmic Muons, Ion Beams and Cancer Therapy
The plasma panel sensor is an ionizing photon and particle radiation detector derived from PDP technology with high gain and nanosecond response. Experimental results in detecting cosmic ray muons and beta particles from radioactive sources are described along with applications including high energy and nuclear physics, homeland security and cancer therapeutics