Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: FRIDAY, March 3, 1995                   TAG: 9503030130
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A-1   EDITION: METRO 
SOURCE: Associated Press
DATELINE: BATAVIA, ILL.                                LENGTH: Medium

PHYSICISTS ISOLATE FINAL `PIECE OF THE PUZZLE'

In what some scientists say could be the last hurrah for groundbreaking U.S. research into the fundamental nature of matter, physicists announced Thursday they have isolated the long-theorized subatomic particle known as the ``top quark.''

The breakthrough came from two teams of physicists - each about 450 members strong - working in good-natured competition at the Fermi National Laboratory's particle accelerator to isolate the last of six tiny building blocks of matter.

``There was this one piece of the puzzle missing,'' said Stanford University physicist Michael Peskin. ``You know what shape it is and you know where it goes, but you're not satisfied until you can put it in the right place.''

Physicists across the nation eagerly watched the announcement broadcast live from Fermi, about 30 miles west of Chicago, where scientists could barely contain their enthusiasm.

``We're delighted that the top quark has waited for discovery until we were mature enough to make it,'' said Paul Grannis, who like many of the researchers divides his time between Fermi and a university - in his case, the State University of New York at Stony Brook.

Some scientists suggested that the frontier for research into the nature of matter may shift now from the United States to Europe, where a larger, better supercollider necessary for particle research is to be built.

In 1993, Congress killed the superconducting supercollider in Texas, a project that was supposed to have updated the Fermi facility.

``We have yet to build the machine that could let us address the really exciting questions,'' said Harvard University physicist Sheldon Glashow.

Scientists acknowledged that any practical applications for the discovery are years away.

Scientists have theorized about the top quark since the 1960s, when California Institute of Technology physicist Murray Gell-Mann sought to explain subatomic matter in terms of new units he named quarks.

Had the existence of the top quark been disproved, it would have thrown current theories about the nature of matter and creation of the universe into disarray.