Transverse Force on Quarks in Deep-Inelastic Scattering

Transverse single-spin asymmetries are not the only observable where the transverse force on quarks in DIS plays a role. For example, higher-twist effects in polarized inclusive DIS can be related to that force. Furthermore the torque due to that force is relevant when comparing the Jaffe-Manohar with the Ji definition for quark orbital angular momentum. I explain the origin of that force in semi-classical pictures and discuss connections and differences with the Aharonov-Bohm effect.