Английский язык: Аннотирование и реферирование текста

211 along. While observing a beam of muon neutrinos generated by one of Fermilab's particle accelerators, the MiniBooNE researchers found that an unexpectedly high number of the particles in the low-energy range (below 475 million electron volts) had transformed into electron neutri- nos. After a year of analysis, the investigators have failed to come up with a conventional explanation for this so-called low-energy excess. The mystery has focused attention on an intriguing and very unconven- tional hypothesis: a fourth kind of neutrino may be bouncing in and out of extra dimensions. String theorists, who seek to unify the laws of gravity with those of quantum mechanics, have long predicted the existence of extra di- mensions. Some physicists have proposed that nearly all the particles in our universe may be confined to a four-dimensional "brane" embedded within a 10-dimensional "bulk." But a putative particle called the sterile neutrino, which interacts with other particles only through gravity, would be able to travel in and out of the brane, taking shortcuts through the extra dimensions. In 2005 Heinrich Pas, now at the University of Dortmund in Germany, Sandip Pakvasa of the University of Hawaii and Thomas J. Weiler of Vanderbilt University predicted that the extradi- mensional peregrinations of sterile neutrinos would increase the prob- ability of flavor oscillations at low energies – exactly the result found at MiniBooNE two years later. Energized by the prospect of discovering new laws of physics, the MiniBooNE team soon proposed a follow-up experiment called Mi- croBooNE that could test the sterile neutrino hypothesis. The new de- tector, a cryogenic tank filled with 170 tons of liquid argon, would be able to detect low-energy particles with much greater precision than its predecessor could. A particle emerging from a neutrino interaction would ionize the argon atoms in its path, inducing currents in arrays of wires at the perimeter of the tank. Scientists could then pinpoint the trajectory of the particle, allowing them to better distinguish between electron neutrino interactions and other events and thus determine whether there really is an excess of oscillations at low energies.