Measurements of Missing Mass (MM) Spectra from π−p ⇒ (MM)−pat 8, 11, 13.5, and 16 GeV

Measurements of missing mass (MM) spectra from π − p ⇒ ( MM ) − p at 8, 11, 13.5, and 16 GeV are reported. The MM mass range examined is 0 ≤ M 2 ≤ 7.3 GeV 2 with t (the proton four momentum transfer squared) in the interval 0.2 ≤ ∣ t ∣ ≤ 0.3 GeV 2 . Narrow resonances (R1, R2, R3, S, T, and U) with cross sections and widths reported by the CERN missing mass group are ruled out by the data. The cross sections d 2 σ/ dtdM 2 show evidence for triple factorizability of the form d 2 σ dtdM 2 ≃ D ( P B ) A ( M 2 ) G ( P ⊥ 2 ) where P B is the incident beam momentum,and P ⊥ 2 is the perpendicular component of the detected proton's momentum with respect to the beam direction.