Abstract
In addition to optimal conditions, invariant laws of Lorentz, parity and time
reversal are imposed to find the relation between observables (spin rotation
parameters) and bilinear combination of helicity amplitudes in pion-proton
elastic scattering at 6.0 GeV/c. By normalizing the differential cross-section to
unity, the magnitudes of helicity amplitudes and the angle between them are
determined. Planar amplitudes are found in terms of the helicity amplitudes and
the angle between momentum vector and quantization direction in the reaction
plane.
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