First four-quark particle may have been spotted
Finding might shed light on how nucleus is held together
By Andrew Grant
An exotic subatomic particle could be the first amalgamation of more than three quarks — a fundamental building block of atoms — to be produced experimentally. If it is what physicists think it is, the particle could provide clues about the force that holds nuclei together and perhaps about the earliest moments of the universe.
“We have very solid evidence of an unconventional particle,” says Ronald Poling, a physicist at the University of Minnesota in Minneapolis. “But it’s the interpretation — the possibility that it has four quarks — that makes it very exciting.” The details of the particle, inelegantly named Zc(3900), appear June 17 in Physical Review Letters.