Use of a large multicell ionization detector - The external particle identifier - In experiments with the BEBC hydrogen bubble chamber

Fast secondary particles from interactions of K+ at 70 GeV/c and K- at 110 GeV/c in the BEBC hydrogen bubble chamber are identified by use of the relativistic rise of ionization in argon. The ionization is measured in a large multicell ionization counter system, the External Particle Identifier (EPI). The operation of this hybrid system, the calibration and the procedures of off-line analysis leading to particle identification are described. For a sample of 9283 secondary particles collected in the K+ p experiment, we present the measurements of ionization, and the determination of acceptance and identification efficiencies. The momentum-dependent populations of pions, kaons and protons have been obtained. Track by track identification procedures yielding samples of pions and kaons with a contamination {less-than or approximate} 12% are discussed. A study of the resolution of the EPI in these experimental conditions shows average values in a range of 7.6% to 11% depending on the number of ionization samples remaining after removal of background. These values extrapolate to a value consistent with the 6.6% fwhm measured over the whole device for single particles during calibration with a 50 GeV/c π- beam. © 1983.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

On the ontological status of norms

Abstract. This article describes an ontological model of norms. The basic assumption is that a substantial part of a legal system is grounded on the concept of agency. Since a legal system aims at regulating a society, then its goal can be achieved only by affecting the behavior of the members of the society. We assume that a society is made up of agents (which can be individuals, institutions, software programs, etc.), that agents have beliefs, goals and preferences, and that they commit to intentions in order to choose a line of behavior. The role of norms, within a legal system, is to specify how and when the chosen behavior agrees with the basic principles of the legal system. In this article, we show how a model based on plans can be the basis for the ontological representation of norms, linking them to the upper level of a philosophically well-founded ontology (DOLCE); in this way, the model is set in a wider perspective, which opens the way to further developments.

Use of a large multicell ionization detector - The external particle identifier - In experiments with the BEBC hydrogen bubble chamber

Fast secondary particles from interactions of K+ at 70 GeV/c and K- at 110 GeV/c in the BEBC hydrogen bubble chamber are identified by use of the relativistic rise of ionization in argon. The ionization is measured in a large multicell ionization counter system, the External Particle Identifier (EPI). The operation of this hybrid system, the calibration and the procedures of off-line analysis leading to particle identification are described. For a sample of 9283 secondary particles collected in the K+ p experiment, we present the measurements of ionization, and the determination of acceptance and identification efficiencies. The momentum-dependent populations of pions, kaons and protons have been obtained. Track by track identification procedures yielding samples of pions and kaons with a contamination {less-than or approximate} 12% are discussed. A study of the resolution of the EPI in these experimental conditions shows average values in a range of 7.6% to 11% depending on the number of ionization samples remaining after removal of background. These values extrapolate to a value consistent with the 6.6% fwhm measured over the whole device for single particles during calibration with a 50 GeV/c π- beam. © 1983