News Briefs; October 2000; Scientific American Magazine; by Graham P. Collins, Steve Mirsky, Philip Yam, Julia Karow, Rebecca Lipsitz; 2 Page(s)

The Tau of Neutrinos On July 21 physicists announced that they had directly detected the tau neutrino, the third such species (after the electron and muon neutrinos), completing the third and presumably final generation of elementary particles ofmatter in the Standard Model of particle physics (see www.fnal.gov/ pub/standardmodel.html). The experiment, conducted in 1997 at the Fermi National Accelerator Laboratory in Batavia, Ill., slammed protons into tungsten, producing a thick stream of particles. Powerful deflecting magnets and 15 meters of steel shielding removed all but the neutrinos-almostmassless, barely interacting particles. An estimated one in a trillion of the beam's tau neutrinos then produced its distinctive partner, a tau lepton, in the experiment's detector. Three years of painstaking data analysis, conducted at Nagoya University in Japan, turned up four tau neutrino events among nearly seven million candidate interactions.-Graham P. Collins

Sea of Troubles Giant aliens have been spotted in the northern Gulf ofMexico. An Australian native normally six to eight inches across, the spotted jellyfish (Phyllorhiza punctata) is reaching diameters of two feet, apparently by feeding in the algaerich waters of the Mississippi Sound. Theymay threaten the local shrimp industry-the second most valuable fishery in the U.S., behind that for Alaskan salmon. The crucial questions are whether the creatures will survive the winter and if they'll turn their attention to shrimp eggs and larvae. If they do, "their effect on the Gulf 's environment and commercial fisheries could be one of the area's biggest problems next year," says Monty Graham of the Mississippi-Alabama Sea Grant Consortium, a group made up of eight local universities and research facilities.-Steve Mirsky