Recent results from the Crystal Barrel collaboration at CERN have been presented at this year's summer conferences. Taken in conjunction with theoretical predictions (including lattice gauge calculations), these results identify the fo(1500) and fo(1720) resonances as the most likely glueball states.
The following items relate to this story (in reverse chronological order):
Senior physicists meeting in Germany last week were intrigued to hear the existence of a missing subatomic particle confirmed - albeit in the shape of no less than three rival contenders.
The missing particle is predicted by theory to be made up of particles known as "gluons", so called because they hold quarks together to form protons and neutrons, which in turn make up the nucleus of the atom. Theory predicts that these gluons should be able to bind to themselves to form lumps of pure energy - known in the trade as "glueballs". It had been thought that such glueballs had never been observed in the laboratory, despite a whole host of experiments devised to prove their existence. But the latest results discussed at the LEAP (Low Energy Antiproton Physics) meeting held in Dinkelsbuhl have cast new light on the twenty year old mystery:
Measurements taken from the Crystal Barrel detector, a large international collaboration working at the massive European atom-smashing laboratory CERN near Geneva, indicate that one of three known particles must be a type of glueball; though at this stage it's hard to say exactly which is which. Says Frank Close, a theoretician from the UK's Rutherford Appleton Laboratory in Oxfordshire: "It's like having three suspects in an identity parade and knowing that one of the line-up is definately guilty. Naturally, we need to know who is the ring leader and who are the accomplices..."
Final confirmation of the glueball's existence is important because it shows once again that the physicists' theories about how subnuclear forces work are on the right track, and this will hopefully lead to a greater understanding of how the universe was originally formed. As to which of the three contenders is the real glueball, only time (and a little more detective work) will tell.
[News item supplied by Roger W. Poultney - September 1996]
See "New Scientist" Vol 151 No 2043 (17 August 1996) p.18 [item retitled and shortened by IPC magazines.]