(mib) Higgs-Boson's game of hide-and-seek will soon be over. Monday last the first magnet module for the CMS detector arrived at the European particle-physics laboratory near Geneva (CERN) (1). Four further modules should be delivered before the end of 2004.

45 tonnes of baggage: the heavy load special transport arrives at CERN near Geneva. large

With 2.7 gigajoules in its superconducting magnet, the CMS detector contains the highest amount of energy ever stored in a magnet. This Compact Muon Solenoid Detector (2) that arrived at CERN is one of four detectors destined for the new particle accelerator, the Large Hadron Collider (LHC) (3). Researchers at ETH working with Professor Felicitas Pauss from the Institute of Particle Physics (4), have high hopes that this will help to track down the Higgs-Boson particle. First postulated by the Scottish physicist Peter Higgs as responsible for matter, proof of this particle has so far eluded scientists.

Room for the CMS detector. Together with three further detectors it will analyse data from the ring of the LHC particle accelerator. large

The inner life of the CMS detector. The vacuum chamber inside the CMS is visible, surrounded by the (red) muon chambers. Picture: Michael Dröge large

Three years ago, using 114-electron-gigavolt, physicists discovered first traces of products of disintegration. These could be an indication of Higgs particles, thereby confirming the standard model. In addition, physicists hope that the new detector will help to solve some puzzles of the big bang. Because there are still some open questions. Where, for example, has the bulk of antimatter disappeared to, which was present with matter in equal parts at the beginning of our universe? And, is there a parallel universe to ours, as would be theoretically allowed by the supersymmetry theory?

1940 scientists from 150 institutions and 36 countries are involved with the data that the CMS detector will provide. Together with industrial partners ETH Zurich is responsible for the superconducting magnet cable made from a niobium-titanium alloy, encased in an aluminium shell. The first module, that was delivered lately, is 2.5 metres long, has an inner diameter of 6.3 metres and weighs 45 tonnes. The superconducting magnet will have a total weight of 220 tonnes and will run on 20,000 ampere. The entire CMS detector will weigh a multiple of this at 12,500 tonnes. According to the planning timetable, the LHC will begin its work in 2007.