Anomalous Quark Chromomagnetic Moment and Single-Spin Asymmetries

Understand

We discuss a nonperturbative mechanism for the single-spin asymmetries (SSA) in the strong interaction.

• This mechanism is based on the existence of a large anomalous quark chromomagnetic moment (AQCM) induced by the nontrivial topological structure of QCD vacuum.
• Our estimations within the instanton liquid model for QCD vacuum show that AQCM generates very large SSA on the quark level.
• Therefore, this mechanism can be responsible for the anomalously large SSA observed in different high energy reactions with hadrons.