Study of s-Channel and t-Channel Helicity Conservation in the Diffractive Part of the Reaction pi+- p --> pi (n pi) at 16-GeV/c

The Aachen-Berlin-Bonn-CERN-Heidelberg collaboration Grässler, H. ; Kirk, H. ; Otter, G. ; et al.
Nucl.Phys.B 95 (1975) 1-11, 1975.
Inspire Record 99495 DOI 10.17182/hepdata.31974

By means of an isospin analysis of the reaction π ± p→ π (N π ) at 16 GeV/ c we have determined the decay angular distributions of the N π system with I= 1 2 produced by isospin zero exchange. Helicity conservation is not observed in the t -channel for the N π mass region below 1.6 GeV, where diffraction dissociation of the proton is supposed to dominate. There are indications for approximate t -channel helicity conservation for N ∗ (1690) production. In the helicity frame, the experimental data are not in agreement with s -channel helicity conservation over the whole N π mass range investigated. Thus the diffractive process N→N π differs both from the process N→N ππ (or π → πππ and K→K ππ ) which approximately conserves t -channel helicity and from the elastic scattering N→N which conserves helicity in the s -channel.

2 data tables

No description provided.

FIT TO ISOSPIN HALF NUCLEON RESONANCE PRODUCTION WITH ISOSPIN ZERO EXCHANGE.