Search for long-lived heavy particles

We have performed high-sensitivity search for massive long-lived particles produced at 2.5 mrad by 400-GeV/c protons on a beryllium target using time-of-flight, Cherenkov, and calorimetric techniques. A total of 10/sup 11/ light particles (..pi../sup -/,K/sup -/,p-bar) was sampled at 70 KeV/c. The experiment places a limit of 1.1 x 10/sup -37/ cm/sup 2//(GeV/c)/sup 2/ nucleon on the invariant cross section for the production of stable particles in the mass range of 4 to 10 GeV/c/sup 2/.