UA4 experiment (COULOMB[1]) was a high-energy physics experiment at the Proton-Antiproton Collider at CERN. The UA4 collaboration consisted of physicists from Amsterdam, Genova, Napoli, Pisa, Roma, California and CERN.[2] UA4 was approved on 18 January 1979, and the first phase of data taking lasted until 17 June 1985. The spokesperson of UA4 was Giorgi Matthiae.[1]
 | |
| Key SppS Experiments | |
|---|---|
| UA1 | Underground Area 1 |
| UA2 | Underground Area 2 |
| UA4 | Underground Area 4 |
| UA5 | Underground Area 5 |
| SppS pre-accelerators | |
| PS | Proton Synchrotron |
| AA | Antiproton Accumulator |
UA4 was followed by UA4/2, a collaboration between Genova, Roma, Paris, Prague, Valencia and CERN.[3] The purpose of UA4/2 was to measure the ratio of real to the imaginary part of the forward elastic scattering amplitude.[3] It was approved in July 1990, and recorded data throughout 1991.
The objective of the UA4 experiment was to measure the antiproton-proton cross-section, in order to show that cross-sections rising with energy are a characteristic of strong interaction.[2] One had previously measured proton-antiproton cross-sections at the Intersecting Storage Rings, but as the Proton-Antiproton Collider — a modification of the Super Proton Synchrotron — began operating, the measurements could be done in a new energy range: up to 540 GeV center-of-mass energy.
Elastic events were detected by high resolution wire chambers and scintillation-counter hodoscopes. A system of drift chamber telescopes and counter telescopes were placed on the left and the right side of the crossing region to detect inelastic events.[4]
After the period of data taking, the UA4 collaboration could conclude that proton-antiproton cross-section indeed rises with energy.[4]
See also
editReferences
edit- ^ a b "UA4/COULOMB". CERN Greybook. Retrieved 19 July 2017.
- ^ a b Battistion; et al. (6 October 1978). "Proposal: The Measurement of Elastic Scattering and of the Total Cross-section at the CERN proton-antiproton Collider" (PDF). SPSC. 78–105, P114. Retrieved 19 July 2017.
- ^ a b Augier; et al. (1997). "The UA4/2 experiment at the CERN SppbarS Collider". Nuclear Instruments and Methods in Physics Research. 389 (1997): 409–414. Bibcode:1997NIMPA.389..409A. doi:10.1016/S0168-9002(97)00330-6.
- ^ a b Van Swol, R. (31 August 1983). "Results from the UA4 Collaboration". 3rd International Conference on Physics in Collision. 3rd International Conference on Physics in Collision. Como, Italy: Gif-sur-Yvette: Ed. Frontières. pp. 53–65. ISBN 9782863320259.