Collision course. Delegates at the second workshop on the Physics Potential and Physics monitor Development of Muon Colliders, held in Sausalito, California, in November.
Muon colliders
he increasing interest in the T possibility of positive-negative muon colliders (October 1994, page 24) was reflected in the second workshop on the Physics Potential and Development of Muon Colliders, held in Sausalito, California, from 16-19 November, with some 60 attendees. It began with an overview of the particle physics goals, detector constraints, the muon collider and mu cooling, and source issues. The major issue confronting muon development is the possible luminosi ty achievable. Two collider energies were considered: 200 + 200 GeV and One interesting possibility is the cooling and acceleration in crystals 2 + 2 TeV. The major particle physics direct observation of the supersym at TRIUMF. goals are the detection of the higgs metric higgs. The detector back One major conclusion of the meet boson(s) for the lower energy collid grounds will be considerable due to ing is that muon colliders are comple er, together with WW scattering and high energy muon decays upstream, mentary to both proton-proton (LHC) supersymmetric particle discovery. however the working group conclud and electron-positron (NLC) colliders, At the first such workshop, held in ed that these backgrounds might be especially for the higgs Sector and Napa, California, in 1992, it was manageable. for the study of supersymmetric estimated that a luminosity of some One key to achieving a high lumi particles. 1030 and 3 x 1032 cm2s1 for the low nosity collider is the collection of a The third meeting in this series will and high energy collider might be maximum of muons from pion de be held in San Francisco, California, achieved (papers from this meeting cays. This is far from trivial and leads in December. Another workshop, were published in the October issue to conclusions from groups 2 and 3 addressing machine issues, will be of NIM). This was considered a that the present uncertainty in lumi held on Long Island in October. somewhat conservative estimate at nosity is of order 102±1 (these orders Proceedings of the Sausalito work the time. of magnitude unfortunately span the shop will be published by the Ameri At the Sausalito workshop the goal range from being uninteresting to can Institute of Physics. was to see if a luminosity of 1032 to being very interesting!). Hopefully 1034 for the two colliders might be this uncertainty can be reduced From David Cline UCLA achievable and usable by a detector. before the next meeting. There were five working groups - Perhaps the most interesting aspect physics, 200 + 200 GeV collider, of a muon collider is the need to cool 2 + 2 TeV collider, detector design the positive and negative muon Cosmic rays of the and backgrounds, and muon cooling beams over a very large dynamic and production methods. Considera range. highest energies ble progress was made in all these Three experimental programmes areas at the workshop. were discussed and are being ith the objective of designing a The muon collider has a powerful initiated to study muon cooling: W new detector to probe the physics reach, especially if muon at Brookhaven, Fermilab, and a behaviour of the highest energy polarization can be maintained. UCLA group is proposing to study cosmic rays, a Giant Airshower
16 CERN Courier, January/February 1995