A sensitive search for the lepton-number-violating decay Ξ-→pμ-μ- has been performed using a sample of ∼109 Ξ- hyperons produced in 800 GeV/c p-Cu collisions. We obtain B(Ξ-→pμ-μ-)<4.0×10-8 at 90% confidence, improving on the best previous limit by 4 orders of magnitude.
Phys. Rev. Lett. 94, 181801 (2005)
Available at: http://works.bepress.com/timothy_holmstrom/4/