Search for Invisible Decay of the $Î¥(1S)$
arXiv:hep-ex/0611041 · doi:10.1103/PhysRevLett.98.132001
Abstract
We report results of a search for the invisible decay of the Upsilon(1S) via the Upsilon(3S)->pi+pi-Upsilon(1S) transition using a data sample of 2.9 fb^{-1} at the Upsilon(3S) resonance. The data were collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. No signal is found, and an upper limit for the branching fraction at the 90% confidence level is determined to be B(Upsilon(1S)->invisible) < 2.5x10^{-3}.
6 pages, 4 figures