Observation of Interference Between I(u)=1/2 and I(u)=3/2 Baryon Exchange Amplitudes in 4-GeV/c Backward Inelastic Scattering

Gidal, G. ; Chapman, J.W. ; Ely, R.P. ; et al.
Phys.Lett.B 76 (1978) 657-662, 1978.
Inspire Record 122008 DOI 10.17182/hepdata.27433

Interference between the I u = 1 2 and I u = 3 2 baryon exchange amplitudes is observed in the reaction π − p → p π − π 0 , with the proton produced forward with cos θ p ∗ >0.8 . The Dalitz plot shows that the reaction is dominated by the quasi two body final states ρ − p( δ exchange) and N ∗0 (1670)π 0 ( N exchange ) , with δ(1238), N ∗ (1520) and higher mass N ∗ 's also produced. The relative phase between the ρ and the N ∗ (1670) production amplitudes is measured to be 135° ± 10° and is compared with the Regge pole signature factor phase predictions.

1 data table

THE RELATIVE PRODUCTION AMPLITUDE PHASE FROM INTERFERENCE IS 135 +- 10 DEG.