Tomography of exotic hadrons in high-energy exclusive processes

Abstract

We investigated the possibility of determining internal structure of exotic hadrons by using high-energy reaction processes, where quarks and gluons are appropriate degrees of freedom. In particular, it should be valuable to investigate the high-energy exclusive processes which include generalized parton distributions (GPDs) and generalized distribution amplitudes (GDAs). The GPDs and GDAs contain momentum distributions of partons and form factors. We found that the exotic nature appears in momentum distributions of quarks as suggested by the constituent-counting rule and in the form factors associated with exotic hadron sizes and the number of constituents. Transition GPDs to exotic hadrons could probe such exotic signatures. We also propose that these exotic signatures should be found in exclusive production processes of exotic hadrons from gamma^* gamma in electron-positron annihilation. For example, the GDAs contain information on a time-like form factor of the energy-momentum tensor of a hadron h. We show that the cross section of e gamma -> e+hbar h is sensitive to the exotic signature by looking at the hbar h invariant-mass dependence by taking light hadrons, h=f_0 (980) and a_0 (980). From such GDA measurements, the tomography of exotic hadrons becomes possible, for example, by Belle and BaBar experiments and by future linear collider.