2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/41805A system of quarks interacting with chiral fields is shown to provide a physical realization of a "non-standard" time reversal for particle multiplets which mixes the multiplet components. We argue that, if the internal structure of the nucleon is governed by a chiral dynamics, the so-called T-odd quark distribution functions are not forbidden by time-reversal invariance and hence might be non vanishing. This agrees with some other recent results. From a phenomenological point of view, this would give rise to single-spin asymmetries in inclusive processes involving a transversely polarized nucleon: in particular, in pion lepto- and hadro-production and in Drell-Yan processes.LaTeX2e, 11 pages, no figuresHigh Energy Physics - Phenomenologytext