Search for exotic states, BNL experiments E818 and E852

Abstract

We have performed an experiment (E-818) to search for exotic states in the reaction π −p → X −p at 18 GeV/c at the Brookhaven MPS-II. The X − was detected through the sequential decay X − → f 1(1285) π −; f 1(1285) → K +K 0s π −. In the flux tube model such final states are expected from the decay of explicitly exotic J PC = 1 −+ hybrid mesons. We present preliminary results of this experiment and estimates of the expected sensitivity to hybrid states. We also describe the status of a new experiment (E-852) to search for exotic mesons in both neutral and charged final states in the reactions π −p → M 0n and π −p → M −p at 21 GeV/c where M is a meson decaying into photons and 0, 1 or 2 charged particles.