629162 DELETED

Detector for the UA1 experiment during assembly 1981 The UA1 detector, shown here in its 'garage' position, was a multi-purpose detector. It covered as large a solid angle as possible and could detect hadron jets, electrons and muons. This was used between 1981 and 1993 on the SPS collider at CERN to observe the proton-antiproton collisions. UA1 was used along with UA2 to discover the W and Z bosons in 1983, which lead to Nobel Prizes for Carlo Rubbia and Simon van der Meer in 1984. PHOTOLAB

UA1: first Z event recorded 1983 This image taken by the UA1 experiment on 30 April 1983 was the first detection of a Z0 particle. UA1 observed proton-antiproton collisions on the SPS between 1981 and 1993 to look for the Z and W bosons, which mediate the weak fundamental force. The Z0 decays very quickly so cannot be seen, but the electron-positron pair produced in the decay can be seen in blue. PHOTOLAB

Detector for the UA2 experiment 1987 Detector for the UA2 experiment, for the study of proton-antiproton collisions in the SPS between 1981 and 1993. It was used, along with UA1 (another experiment on the SPS), to discover the W and Z bosons in 1983, which won Carlo Rubbia and Simon van der Meer the Nobel Prize in 1984. PHOTOLAB

The UA1 central detector, part of an exhibition about the Weak Force in Microcosm 1999 <!--HTML-->Photo 09 : CERN's Director General, Luciano Maiani, at the opening of an exhibition about the Weak Force in Microcosm. <br>Photo 01 : CERN's Director General, Luciano Maiani, looking at the UA1 central detector at the opening of an exhibition in Microcosm. PHOTOLAB

UA1: W particle decay 1982 The discovery of the W particle in the UA1 detector from the October-December 1982 run of the proton-antiproton collider, producing a high transverse energy electron (arrowed). This particle is produced back-to-back with 'missing energy', indicative of the emission of an invisible neutrino. The UA1 detector ran on the SPS accelerator at CERN between 1981 and 1993. PHOTOLAB