Some of the strangest atomic nuclei ever observed have made fleeting appearances
in a recent accelerator experiment. Whereas ordinary nuclei contain protons and
neutrons, so-called hypernuclei produced in an experiment at Brookhaven National
Laboratory in Upton, N.Y., also contain exotic particles quite different from
those in ordinary matter. Although such particles, known as lambdas, have been
spotted in nuclei before, this is the first time that nuclei with pairs of these
exotic particles have been generated by the dozen, scientists say.