Construction of tensor exchange amplitudes in KN and [formula omitted] CEX reactions

Abstract

K +n charge exchange (CEX) polarization data obtained recently by the Saclay group at CERN are supplemented by differential cross-section data and by information on K −p CEX, and used to construct tensor exchange non-flip and flip components T 0 and T 1 of the s-channel helicity amplitudes directly from data at 6 GeV/ c and for | t| ⩽ 0.9. Vector exchange amplitudes are assumed to be known from πN scattering. The sensitivity of solutions to the uncertainties in the input data is examined in great detail. In general we find a unique solution for all t. We observe new features in the t-structure of non-flip and flip amplitudes. Re T 0Re T 0 have simple zeros at t ≈ −0.45 and t ≈ −0.65. Im T 0 has a dip or a double zero at t ≈ −0.16 and a double zero structure at t ≈ −0.45. Im T 1 has two simple zeros at t ≈ −0.45 and t ≈ −0.70. Violations of weak EXD in both amplitudes correspond to a lower A 2 trajectory by approximately Δα ≈ 0.1. If certain conditions are satisfied by the input data, a discrete ambiguity exists in the solutions for | t| ⩾ 0.55 and this possibility is also carefully examined.