The response of the CMS barrel calorimeter (electromagnetic plus hadronic) to hadrons, electrons and muons over a wide momentum range from 2 to 350 GeV/
c
has been measured. To our knowledge, this is ...the widest range of momenta in which any calorimeter system has been studied. These tests, carried out at the H2 beam-line at CERN, provide a wealth of information, especially at low energies. The analysis of the differences in calorimeter response to charged pions, kaons, protons and antiprotons and a detailed discussion of the underlying phenomena are presented. We also show techniques that apply corrections to the signals from the considerably different electromagnetic (EB) and hadronic (HB) barrel calorimeters in reconstructing the energies of hadrons. Above 5 GeV/
c
, these corrections improve the energy resolution of the combined system where the stochastic term equals 84.7±1.6% and the constant term is 7.4±0.8%. The corrected mean response remains constant within 1.3%
rms
.
The CMS high level trigger Adam, W.; Bergauer, T.; Deldicque, C. ...
The European physical journal. C, Particles and fields,
06/2006, Letnik:
46, Številka:
3
Journal Article
Recenzirano
Odprti dostop
At the Large Hadron Collider at CERN the proton bunches cross at a rate of 40 MHz. At the Compact Muon Solenoid experiment the original collision rate is reduced by a factor of \(\mathcal{O}\) (1000) ...using a Level-1 hardware trigger. A subsequent factor of \(\mathcal{O}\) (1000) data reduction is obtained by a software-implemented high level trigger (HLT) selection that is executed on a multi-processor farm. In this review we present in detail prototype CMS HLT physics selection algorithms, expected trigger rates and trigger performance in terms of both physics efficiency and timing.
We present results on efficiency and time resolution of a resistive plate chamber operating at low gas amplification. The measurements were done within the programme of the RD5 experiment at CERN ...with a pion beam of flux 0.1–3.9 kHz/cm
2.
The amplitude of the signal collected from the PbWO4 crystals of the CMS electromagnetic calorimeter is reconstructed by a digital filtering technique. The amplitude reconstruction has been studied ...with test beam data recorded from a fully equipped barrel supermodule. Issues specific to data taken in the test beam are investigated, and the implementation of the method for CMS data taking is discussed.
The performance of lead tungstate crystals using photomultipliers and Si avalanche photodiodes to detect the scintillation light has been studied using high energy electron, pion and muon beams at ...CERN. Results from tests carried out in 1993 and 1994 are presented. Good energy resolution has been obtained using photomultipliers. Some further development is required of crystals and avalanche photodiodes in order to achieve a performance, with avalanche photodiode readout, similar to that obtained using photomultipliers.
The general scheme for the fast, pipelined first level trigger on high
p
t muons in the CMS detector at LHC is presented. The prototype PACT system was tested in the high momentum muon beams in the ...RD5 experiment during 1993/94 runs. The obtained efficiency curves are shown.
New projective prototypes of a scintillator/lead sandwich type sampling calorimeter Shashlik with a silicon preshower detector have been constructed and tested with an electron beam at CERN-SPS. The ...energy resolution is measured to be
8.7%
E(
GeV)
in stochastic term, 0.330/
E(GeV) in noise term and 0.5% in constant term. The angular resolution is better than
70
mrad
E(
GeV)
.
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