Physicists at UH make
subatomic discovery

University of Hawaii physicists and colleagues have discovered a puzzling subatomic particle they call the Y(3940).

"The whole world is looking for these things and people in Hawaii found them, so we're proud of ourselves," said Stephen Olsen, principal investigator of the UH High Energy Physics Group.

The discoverers are part of an international collaboration of universities and laboratories participating in the Belle experiment at the KEK High Energy Physics Laboratory in Tsukuba, Japan.

The researchers are trying to understand the behavior of matter at the most fundamental level. They're using the world's highest intensity particle accelerator to study differences between properties of matter and antimatter.

The powerful KEKB accelerator generates a huge number of subatomic particles called B mesons and their antimatter counterparts for studies. B mesons disintegrate after a trillionth of a second into decay products detected by the accelerator.

Olsen, spokesman for the experiment, said the new Y particle may be an example of a "hybrid meson."

"If we could really demonstrate it's a hybrid, everybody would be pretty happy with that," Olsen said.

Theorists had predicted such a particle 30 years ago but finding it is "like looking for a needle in a haystack," he said.

"We can only do it because of data for doing antimatter experiments. We have accumulated a huge data set, hundreds of times bigger than anything before. We have 60 examples out of some 500 million B meson decays."

The finding of Y(3940) resulted from an analysis of Belle data by Olsen and Sookyung Choi of Gyeongsang University in Korea.

The discovery will be published in this month's issue of Physical Review Letters, the world's leading physics journal.

UH members of the Belle team in 2003 discovered a subatomic particle called X(3872), known as the "mystery meson."

The new Y(3940) is an enigma, the scientists said.

Other UH participants in the Belle experiment are physics professors Tom Browder, Mike Jones, Mike Peters and Gary Varner, postdoctoral researchers Marlon Barbero and Karim Trabelsi and graduate students Nick Kent, Eric Dobson, Hulya Guler, Himansu Sahoo and Kirika Uchida.