Impact parameter dependent parton distributions are transversely distorted
when one considers transversely polarized nucleons and/or quarks. This provides
a physical mechanism for the T-odd Sivers effect in semi-inclusive
deep-inelastic scattering. The transverse distortion can also be related to
Ji's sum rule for the angular momentum carried by the quarks. The distortion of
chirally odd impact parameter dependent parton distributions is related to
chirally odd GPDs. This result is used to provide a decomposition of the quark
angular momentum w.r.t. quarks of definite transversity. Chirally odd GPDs can
thus be used to determine the correlation between quark spin and quark angular
momentum in unpolarized nucleons. Based on the transverse distortion, we also
suggest a qualitative connection between chirally odd GPDs and the Boer-Mulders
effect.Comment: 12 pages, 1 figure, version to appear in PR