Eur. Phys. J. A (2004) 22: 119-124
https://doi.org/10.1140/epja/i2004-10026-8

Polarization observables in the processes and , in the threshold region, for any spin and parity of the -hyperon

¹ NSC Kharkov Institute of Physics and Technology, 61108, Kharkov, Ukraine
² DAPNIA/SPhN, CEA/Saclay, 91191, Gif-sur-Yvette Cedex, France

^* e-mail: etomasi@cea.fr

Abstract

Using the symmetry properties of the strong interaction, such as the Pauli principle, the P-invariance, the conservation of the total angular momentum and isotopic invariance, we establish the spin structure of the threshold matrix elements for the processes and , in the near-threshold region, in a model-independent way, which applies to any spin and parity of the -hyperon. We predict the double-spin observables for these processes, such as the dependence of the differential cross-section on the polarizations of the colliding nucleons, and the coefficients of polarization transfer from a nucleon beam or target to the produced - or -hyperon. We prove that these observables are sensitive to the P-parity of the -baryon, for any value of its spin. As an example of dynamical considerations, we analyzed these reactions in the framework of K-meson exchange.