54755032
Spatial resolution in Micromegas detectors
The performance of a telescope of Micromegas detectors has been studied in a pion beam at the CERN PS. With a gas "lling of CF and 20% isobutane and with a strip pitch of 100m an accuracyof 14 $3m on the spatial resolution has been measured at normal incidence. A simulation demonstrates that the resolution is limited bythe size of the holes of the mesh of the detector and could be reduced to 11m in the same conditions with smaller holes. Even further improvement down to 8.5m is feasible for the same gas with an optimized 75m strip pitch. 2001 Elsevier Science B.V. All rights reserved.
199676084
Measurement of the differential q**2 spectrum and forward-backward asymmetry for B ---> K* l+ l-
62211675
PAT: The CMS Physics Analysis Toolkit
The CMS Physics Analysis Toolkit (PAT) is presented. The PAT is a high-level analysis layer enabling the development of common analysis efforts across and within Physics Analysis Groups. It aims at fulfilling the needs of most CMS analyses, providing both ease-of-use for the beginner and flexibility for the advanced user. The main PAT concepts are described in detail and some examples from physics analyses are given.
209834639
Search for supersymmetry in events with b-quark jets and missing transverse energy in pp collisions at 7 TeV
Results are presented from a search for physics beyond the standard model based on events with large missing transverse energy, at least three jets, and at least one, two, or three b-quark jets. The study is performed using a sample of proton-proton collision data collected at sqrt(s)=7 TeV with the CMS detector at the LHC in 2011, with the missing transverse energy distribution as the principal search variable. The integrated luminosity of the sample is 4.98 inverse femtobarns. The observed number of events is found to be consistent with the standard model expectation, which is evaluated using control samples in the data. The results are used to constrain cross sections for the production of supersymmetric particles decaying to b-quark-enriched final states in the context of simplified model spectra.
122757815
Performance Study of the CMS Barrel Resistive Plate Chambers with Cosmic Rays
In October and November 2008, the CMS collaboration conducted a programme of cosmic ray data taking, which has recorded about 270 million events. The Resistive Plate Chamber system, which is part of the CMS muon detection system, was successfully operated in the full barrel. More than 98% of the channels were operational during the exercise with typical detection efficiency of 90%. In this paper, the performance of the detector during these dedicated runs is reported.
118843154
Performance and operation of the CMS electromagnetic calorimeter
The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75 848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented.
122778605
Monopole trigger for the streamer tube system in macro
Abstract We report the study done on the streamer tube trigger for monopoles to be used in MACRO. The acceptance, trigger rate and electronic efficiency of the trigger system are discussed.
10789270
Preliminary Result of Frascati (ADONE) on the Nature of a New 3.1-GeV Particle Produced in e+ e- Annihilation
fications system is not functioning and we therefore cannot separate muons from strongly interacting particles. However, outside the peak the data are consistent with our previously measured p. -pair cross section. Since a large wg or EE branching ratio would be unexpected for a resonance this massive, the two-body enhancement observed is probably but not conclusively in the p, -pair channel. The e'e hadron cross section is presumed to go through the one-photon intermediate state with angular momentum, parity, and charge conjugation quantum numbers J~c = 1 . . It is difficult to understand how, without involving new quantum numbers or. selection rules, a resonance in this state which decays to hadrons could be so nal row. We wish to thank the SPEAR operations staff for providing the stable conditions of machine performance necessary for this experiment. Special monitoring and control techniques were developed on very short notice and performed excellently.
126412612
Search for astrophysical point sources of muons with the MACRO detector
122501894
UVT-PMMA Cherenkov counter performance tests
Abstract UVT-PMMA Cherenkov detectors have been tested in a particle beam at the Frascati electron linear accelerator. The scintillation light is 1 45 of the Cherenkov light. These counters have good uniformity, in spite of the strong angular dependence of the Cherenkov light.
121781569
Experimental Test of Higher-Order QED and a Search for Excited Muon States
The reactions e/sup +/e/sup -/..--> mu../sup +/..mu../sup -/..gamma gamma.. and e/sup +/e/sup -/..--> mu../sup +/..mu../sup -/..gamma.. have been studied at ..sqrt..s = 29 GeV with the MAC detector at the SLAC storage ring. The measured cross sections, charge asymmetry, and invariant-mass distributions are in good agreement with the predictions of QED theory. Limits are derived for the production of excited muon states.