five quarks for muster mark

Here’s some great news for particle-physics enthusiasts: A new type of subatomic particle has been discovered! And for you non-particle-physics enthusiasts, here’s a primer: Quarks are the elementary particles that make up the subatomic particles that make up atoms that make up everything in the universe. The word quark supposedly derives from a line in James Joyce’s “Finnegans Wake”: “Three quarks for Muster Mark.” And it does take three quarks to make up a neutron or a proton, the building blocks of atomic nuclei. (Two-quark combinations called mesons also exist.) But theory never ruled out the existence of particles consisting of more than three quarks; it’s just that they were never found – until now. A five-quark particle, or “pentaquark,” has been discovered by physicists working at the SPring-8 physics lab in Japan, and confirmed by researchers at the Jefferson National Accelerator Facility in the United States. According to a paper in the July 4 issue of Physical Review Letters, the physicists found the particle (which decays almost immediately) by analyzing the debris of particle-smashing experiments. Ken Hicks, a member of both the US and Japanese teams, attributes the new discovery to more powerful experimental techniques — including more efficient detectors — that allowed the collisions to be better observed.

This news brief appeared in the Random Data column of the Boston Globe’s Health/Science section on 7/08/2003.