Editing UA2 experiment (section)

===Detectors===
The [[UA1]] and the UA2 experiments had many things in common; they were both operating on the same accelerator and both had the same objective (to discover the [[W and Z bosons]]). The main difference was the detector design; UA1 was a multipurpose [[detector]], while UA2 had a more limited scope.<ref name=UA2CERN/> UA2 was optimized for the detection of electrons from W and Z [[Particle decay|decay]]s. The emphasis was on a highly granular [[calorimeter]] – a detector measuring how much energy particles deposit – with spherical projective geometry, which also was well adapted to the detection of [[hadron]]ic [[Jet (particle physics)|jets]].<ref name=Rubbia/> Charged particle tracking was performed in the central detector utilising a combination of [[multi-wire proportional chamber]]s and [[drift chamber]]s and [[hodoscope]]s.<ref>{{cite web | title = Status and First Results from the UA2 Experiment | date = 17 July 1982 | author = [[Peter Jenni]] on behalf of the UA2 Collaboration | url = https://cds.cern.ch/record/139004/files/198208194.pdf | accessdate = 5 September 2022}}</ref> Energy measurements were performed in the calorimeters. Unlike UA1, UA2 had no [[muon]] detector.

[[File:The UA2 detector after upgrade, improved end-cap calorimeters.jpg|thumb|262px|Detector for the UA2 experiment. The picture shows the detector after the 1985-1987 upgrade, when new end-cap [[calorimeter]]s were added to improve the search for the [[top quark]] and new physics.]]

The calorimeter had 24 slices, each weighing 4 tons.<ref>{{cite web |url=https://cds.cern.ch/journal/CERNBulletin/2015/32/News%20Articles/2038517?ln=en |title=Family reunion for the UA2 calorimeter |author=<!--Not stated--> |date=3 August 2015 |website=CERN Bulletin |publisher=CERN |access-date=28 July 2017 }}</ref> These slices were arranged around the collision point like segments of an orange. Particles ejected from the collision produced showers of secondary particles in the layers of heavy material. These showers passed through layers of plastic scintillators, generating light which was read with [[photomultiplier]] by the data collection electronics. The amount of light was proportional to the energy of the original particle. Accurate calibration of the central calorimeter allowed the W and Z masses to be measured with a precision of about 1%.<ref name=Detector>{{cite web |url= http://cern-discoveries.web.cern.ch/cern-discoveries/Story/UA2.html|title=The UA2 detector |date=2003
|publisher=CERN |access-date=22 June 2017}}</ref>