Final-state $NN$-rescattering in spin asymmetries of $d(\gamma ,{\pi }^{-})pp$ reaction

Abstract

The role of the final-state $NN$-rescattering ($NN$-FSI) in the polarization observables of the inclusive reaction $d(\gamma ,{\pi }^{-})pp$, involving polarization of the photon beam and/or the deuteron target, is investigated. Various single- and double-spin asymmetries are studied with respect to the influence of such interaction effect and numerical predictions are given for forthcoming experiments. It has been found that the effect of $NN$-FSI is quite important for the single-spin asymmetries $\Sigma$, $T_{20}$, $T_{21}$ and $T_{22}$ and the double-spin asymmetry $T_{20}^{\ell }$, whereas it is much less important for the vector target asymmetry $T_{11}$ and other beam-target double-polarization asymmetries. Furthermore, we found that the inclusion of the $NN$-FSI improves the description of the LEGS data for the linear photon asymmetry.

Comments: 20 pages, 16 figures, accepted for publication in Nucl. Phys. A, (2005)