Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SUNDAY, April 24, 1994 TAG: 9404240074
SECTION: NATIONAL/INTERNATIONAL PAGE: A4 EDITION: METRO
SOURCE: Chicago Tribune
DATELINE: LENGTH: Medium
For several years, the highest priority at Fermilab near Batavia, Ill., has been to find this particle, which will sew up the accepted theory of the nature of matter.
Quarks are particles that make up the protons and neutrons found in the nuclei of atoms.
They cannot be seen directly, but evidence for them is gathered at Fermilab by accelerating beams of protons into beams of negatively charged protons and then measuring the debris from the collisions.
Earlier experiments have identified five other quark types and have demonstrated that the sixth quark will be the last. But finding it has proven frustratingly difficult.
The Standard Model theory has it that there are three pairs of quarks. The ones already found have been dubbed "Up" and "Down," "Strange" and "Charm," and "Bottom." "Top" would complete the set and validate scientists' understanding of matter.
Years of studying billions of proton-antiproton collisions have failed to yield clear-cut evidence of the top quark, although some events caused rumors among physicists that it had been found more than a year ago.
"You'd never get a single event that would unmistakably demonstrate a top quark," said Larry Jones, a high-energy physicist at the University of Michigan. "Some of the necessary evidence comes in the form of energy that is missing after an event, so you really need a lot of events before you're sure what you're seeing."
Jones said the entire physics community is buzzing with excitement over the likely announcement by Fermilab's Central Detector Facility. Jones is not a member of the Fermilab team but is very active at the LEP physics machine in Geneva, Switzerland.
The CDF will hold a news conference Tuesday to discuss its work.
"They wouldn't hold a press conference unless they were pretty sure they had it," Jones said.
"The collaboration includes hundreds of people, and if you can get them to agree to write a paper saying they've found the top quark, chances are very good they have.
"With that many people, you just don't get the whole group carried away with false enthusiasm. I think this announcement will be very good for Fermilab."
by CNB