New limits on D0 (1.865) production in proton-nucleus collisions at 400 GeV/c

Abstract We present final results of a sensitive search for new particles in π ± K ∓ effective mass spectra observed in proton-nucleus collisions at 400 GeV/ c . We establish a limit for D 0 (1.865) production B π + π − d σ /d y y cm ≈ −0.4. For D 0 → π − K + the limit is 290 nb/nucleon.