Distorted spin-dependent spectral function of an A=3 nucleus and semi-inclusive deep-inelastic scattering processes

The distorted spin-dependent spectral function of a nucleon inside an A = 3 nucleus is introduced as a novel tool for investigating the polarized electron scattering off polarized He-3 in the semi-inclusive DIS regime (SiDIS), going beyond the standard plane-wave impulse approximation. This distribution function is applied to the study of the spectator SiDIS, (3)(H) over right arrowe((e) over right arrow ,e'H-2)X, to properly take into account the final-state interaction between the hadronizing quark and the detected deuteron, with the final goal of a more reliable extraction of the polarized parton distribution g(1)(x) inside a bound proton. Our analysis allows one to single out two well-defined kinematical regions where the experimental asymmetries could yield very interesting information: the region where the final-state effects can be minimized, and therefore the direct access to the parton distributions in the proton is feasible, and the one where the final-state interaction dominates, and the spectator SiDIS reactions can elucidate the mechanism of the quark hadronization itself. The perspectives of extending our approach (i) to the mirror nucleus, H-3, for achieving a less model-dependent flavor decomposition and (ii) to the asymmetries measured in the standard SiDIS reactions, (e) over right arrow + (3)(H) over right arrowe -> e' + h + X, with h a detected fast hadron, with the aim of extracting the neutron transversity, are discussed.