A baryon consisting of four quarks and an antiquark.
- ‘Like recently discovered extrasolar planets that reveal new planetary configurations to astronomers, pentaquarks are alerting physicists to possible new sub-atomic arrangements, he adds.’
- ‘The elusive pentaquark - comprising five quarks - failed to put in an appearance during experiments at the Accelerator Facility in Virginia specifically carried out to search for the little blighter.’
- ‘Quarks come in oddly named ‘flavors,’ and all the new species include two strange, one anti-up, and either an up or a down quark among the five (the pentaquarks discovered last spring all had two ups, two downs, and one anti-strange).’
We take a look at several popular, though confusing, punctuation marks.