Quasi-Bound³He −ηState and Spin-Observables of the Reactionpd→³Heη

Abstract

Abstract.A formalism for total set of spin observables of the reaction pd → 3 Heη derived in a model independent way is presented and a possibility to perform a complete polarization experiment is investigated. Separation of s-and p-wave amplitudes of this reaction in the threshold region allows one to determine a position of the quasibound pole in the 3 He − η system. It is shown that in order to get such a separation one should measure spin-transfer coefficients in addition to analyzing powers and spin-correlations. Specific observables, given by products of one s-and one p-wave amplitudes, are found. Measurement of these observables will provide new independent information on the 3 He − η pole position and this allows one to determine whether the 3 He − η state is quasi-bound or anti-bound.