Large Electron Positron collider (LEP)

The Large Electron-Positron collider (LEP),  was a 27-kilometre-circumference  electron-positron accelerator.

Its construction started in 1983 after the inauguration on 13 September, and the first beam circulated on 14 July 1989.

More information can be found here: https://home.cern/about/accelerators/large-electron-positron-collider

Four detectors : Apparatus for LEP PHysics (ALEPH); DEtector with Lepton, Photon and Hadron Identification (DELPHI); L3  and Omni-Purpose Apparatus for LEP (OPAL) observed particle collisions in the LEP.

During 11 years, the research of LEP’s experiments provided a detailed study of electroweak interactions. LEP was closed down on 2 November 2000, to make way for the installation of the Large Hadron Collider (LHC).

Detectors
Lab

LEP Status

Bit Preservation

“State of the art” bit preservation with regular scrubbing and migration to new media

Data

2 copies on tape at CERN, an additional copy on disk (EOS) being setup.

Additional copies exist outside CERN (ALEPH, OPAL and partial copy for DELPHI)

Documentation

Being revisited – to be “archived” in CERN Document Server for long-term preservation

Software

To be published into CernVMFS

Use Cases

Continued analyses by former collaboration members

Audience

Primarily former collaboration

Value

Analyses, publications and PhDs continue to be produced

Uniqueness

Unique – until and unless certain FCC options are implemented

Resources

Minimal resources for “bit preservation” and storage

Issues

Dependency on CERNLIB

Outlook

Expect to be able to analyse data (ALEPH, DELPHI, OPAL) until at least 2020. Until 2030 should be possible with < (<) 1FTE / experiment / year