Are all Boer-Mulders functions alike?

Chirally odd generalized parton distributions (GPDs) and the Boer-Mulders function provide valuable information about spin-orbit correlations for quarks in nucleons and other hadrons. We compare results for the relevant GPD E¯Tq from a variety of phenomenological models as well as recent lattice results, which all find that E¯Tq>0 for nucleons as well as the pion and for both u and d quark. As a result, the corresponding Boer-Mulders functions are all expected to be negative. We investigate the physical origin of the sign of E¯Tq.