Measurements of Missing Mass (MM) Spectra from π−p ⇒ (MM)−p at 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 ≤ M2 ≤ 7.3 GeV2 with t (the proton four momentum transfer squared) in the interval 0.2 ≤ ∣t∣ ≤ 0.3 GeV2. 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 d2σ/dtdM2 show evidence for triple factorizability of the form d2σdtdM2 ≃ D(PB)A(M2)G(P⊥2) where PB is the incident beam momentum,and P⊥2 is the perpendicular component of the detected proton's momentum with respect to the beam direction.