0000000000089524

AUTHOR

Clemens Becker

showing 2 related works from this author

A measurement of the phases of the CP-violating amplitudes in K0→2π decays and a test of CPT invariance

1990

Abstract The phases of the CP-violating amplitudes in K0→π+π− and K0→2π0 decays, φ+−=46.9°±2.2° and φ00=47.1°±2.8°, have been measured in the same experiment, and a direct comparison gives the phase difference φ00−φ+−=0.2°±2.9°. This result leads to an upper limit on possible CPT violation in the K0 mass matrix, of |(m K 0 −m K 0 )/m K 0 | −18 at the 95% confidence level and is the most stringent test of the equality of particle and antiparticle masses.

Phase differencePhysicsNuclear physicsNuclear and High Energy PhysicsParticle physicsAntiparticleAmplitudeCPT symmetryCP violationLimit (mathematics)Mass matrixlcsh:Physicslcsh:QC1-999Physics Letters B
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A large-area transition radiation detector

1990

Abstract The construction and the operation of a large-area transition radiation detector (TRD) for the NA31 experiment at CERN are described. The TRD incorporates several novel features for stabilizing the detector response. The density of the gas mixture (xenon+helium+methane) in the detection chambers is matched to the carbon dioxide gas in the surrounding radiators by tuning the helium concentration to avoid a hydrostatic pressure difference, which would deform the chamber walls. The chamber pressure is continuously regulated by computer control to maintain it to within 1 μbar of the radiator pressure. The gas gain of each of the four chambers is regulated to better than 0.2% by changin…

PhysicsNuclear and High Energy PhysicsPhysics::Instrumentation and Detectorsbusiness.industryHelium ionization detectorDetectorHydrostatic pressurechemistry.chemical_elementMethaneChamber pressureNuclear physicschemistry.chemical_compoundTransition radiation detectorXenonOpticschemistryDetectors and Experimental TechniquesbusinessInstrumentationHelium
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