P. S. L. Booth

Production of high transverse momentum particles in p-p-collisions in the central region at the CERN ISR

Abstract The inclusive production al all charged particles of transverse momentum p T between 1.5 and 4.4 GeV/ c at centre of mass angles 90° and 59.4° from p-p-collisions with √ s = 44 and 53 GeV has been measured. No strong energy dependence is observed for these transverse momenta.

Evidence for dominant vector-meson production in inelastic proton-proton collisions at 53 GeV c.m. energy

Abstract The Split Field Magnet facility at the CERN ISR has been used to measure inclusive resonance production in inelastic p-p collisions at a c.m. energy of 53 GeV. The mass spectrum of pairs of oppositely charged hadrons shows a strong correlation, which can be explained as a consequence of dominant vector meson production, accounting for more than 60% of all pions and kaons produced.

pp Collisions with a High pT Charged Hadron Trigger at the CERN ISR

Results are presented from an investigation of proton proton collisions at a cm energy of 52.6 GeV in which a charged hadron at large transverse momentum (0.5-6 GeV/c) is emitted near 90° in the cms. Jet-like structures are observed, and their properties discussed in some detail.

Basic concepts and architectural details of the Delphi trigger system

Delphi (DEtector with Lepton, Photon and Hadron Identification) is one of the four experiment of the LEP (Large Electron Positron) collider at CERN. The detector is laid out to provide a nearly 4/spl pi/ coverage for charged particle tracking, electromagnetic, hadronic calorimetry and extended particle identification. The trigger system consists of four levels. The first two are synchronous with the BCO (Beam Cross Over) and rely on hard-wired control units, while the last two are performed asynchronously with respect to the BCO and are driven by the Delphi host computers. The aim of this paper is to give a comprehensive global view of the trigger system architecture presenting, in detail the first two levels, their various hardware components and the latest modifications introduced in order to improve their performance and make more user friendly the whole software user interface.<<ETX>>

The DELPHI experiment

The DELPHI experiment is designed to study in detail the final state particles produced in electron-positron collisions at LEP. The detector has 4π acceptance with emphasis on three-dimensional information, particle identification, high granularity and precise vertex determination. The detector and its performance during its first year of operation is described.