Archives of the UA1 Collaboration, Underground Area 1 Collaboration

Identity Statement [Top]

Reference code(s)



Archives of the UA1 Collaboration, Underground Area 1 Collaboration


From 1978 to 1993

Level of description


Extent of the unit of description

240 boxes; 27 linear meters; 293 items

Context [Top]

Name of creator

CERN (Geneva, Switzerland), UA1 Collaboration.

Administrative history

The UA1 project began in 1976; the idea was to detect the communicators of weak interaction (W and Z bosons), which had been postulated but never observed. To achieve this goal, the experiment planned to collide proton beams with antiproton beams in the Super Proton Synchrotron with an energy of 270 GeV. The problem, which Van der Meer solved, was to stock large amounts of antiprotons.

A new type of detector to see the hypothetical bosons. One of the most important and technically advanced items was the large drift chamber, called the central detector. This drift chamber was 6 meters in length and over 2 meters in diameter. The UA1 experiment also had an electromagnetic calorimeter, a hadron calorimeter and a muon detector. The full detector weighed over 2000 tonnes. The results collected by the detector were recorded on magnetic tapes. Carlo Rubbia managed the construction of this large detector.

In summer 1981 the first collision between protons and antiprotons was recorded. The first experiments began in November 1981. At the beginning of 1982 two accidents damaged the UA1 detector, so the experiment was stopped until summer 1982. UA1 and UA2 experiments started again in September 1982 until December 1982, when the accelerators were switched off for two months. During this time data were analysed and physicists were convinced of having discovered the W boson. This was announced in a press conference held on 25 January 1983. The next step was the discovery of Z boson. The experiments on SPS began again on April 1983, and there were soon major results. On 1 June 1983 CERN formally announced the discovery of the Z boson.

The discovery of W and Z bosons ld to a Nobel prize for Carlo Rubbia and Simon Van der Meer: "The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 1984 jointly to Professor Carlo Rubbia, CERN, Geneva, Switzerland and Dr Simon Van der Meer, CERN, Geneva, Switzerland, for their decisive contributions to the large project, which led to the discovery of the field particles W and Z, communicators of weak interaction".

Immediate source of acquisition or transfer

Received from Alan Norton the 30th May 1995.
Received from Lutz Naumann the 30th May 1995.
Received from Guy Maurin the 30th May 1995.
Received from Antoine Lévêque in April 2000.

Content & Structure [Top]

Scope and content

This collection contains reports, correspondence and official documents related to UA1 Collaboration. It gives an overview of a large, international scientific collaboration.

Appraisal, destruction and scheduling information

All items have been kept in the order in which they were received. Nothing was destroyed.


No further accruals are expected.

System of arrangement

Alan Norton's collection CERN-ARCH-UA1-1 Dates
Scanning 01-001 to 079 1983-07-04 to 1990-08-27
Technical notes and preprints 02-001 to 022 1978-01-30 to 1993-11-26
Meetings 03-001 to 029 1978-02-10 to 1991-08-08
Talks, transparencies, thesis, etc 04-001 to 025 1978-00-00 to 1990-09-14
Miscellaneous 05-01 1978-04-25 to 1990-00-00


Lutz Naumann's collection CERN-ARCH-UA1-2 Dates
Technical files, upgrade 01-001 to 020 1978-00-00 to 1991-05-25
Logbooks 02-001 to 028 1981-08-21 to 1990-10-30


Guy Maurin's collection CERN-ARCH-UA1-3 Dates
Executive Committee 01-001 to 008 1978-04-25 to 1991-05-13
Technical files 02-001 to 017 1979-03-12 to 1993-01-22


Antoine Lévêque's collection CERN-ARCH-UA1-4 Dates
Discussion of proposal 01-001 1977-01-04 to 1979-11-13
Hardware design 02-001 to 009 1977-06-01 to 1985-06-03
Setting up experiment 03-001 to 005 1980-04-08 to 1984-11-21
Collider and running 04-001 to 004 1979-09-00 to 1985-01-28
Description of hardware 05-001 to 002 1982-04-02 to 1985-05-00
Data analysis 06-001 to 019 1981-08-00 to 1985-08-16
Physics memos & transparencies 07-001 to 012 1981-04-22 to 1985-07-24
Improvement program 08-001 to 004 1982-05-14 to 1984-09-24
Collaboration meetings 09-001 to 004 1978-05-01 to 1990-12-07
Coordination & Executive Committee 10-001 to 004 1978-11-24 to 1985-09-10

Conditions of access and use [Top]

Conditions governing access

See file level description and the CERN operational circular No 3: rules applicable to archival material and archiving at CERN. In general, records on any subject that are over 30 years old, and all records of a purely scientific nature, may be consulted.

Conditions governing reproduction

Copyright is retained by CERN, no reproduction without permission.

Language / scripts of material

Most of the material is written in English.

Finding aids

Listed to file level in the CERN Archives Database.

Allied materials [Top]

Related units of description

The UA1 Collaboration contains documents concerning similar experiments, but with a different technology.


For a complete (and quite easy to understand) description of the experiments of UA1 and UA2 Collaborations, see : WATKINS, Peter Maitland: Story of the W and Z, 1986.

The central part of the UA1 detector is exposed in the Microcosm since 1999.

Description control [Top]

Archivist's note

Description prepared by Maryse Moskofian. ISAD(G) description by Marc Reymond.

Date(s) of description

Collection: Geneva, May 2001. ISAD(G) description: Geneva, June 2002. Revised 2007.