Speaker
Description
Hadron tomography can be investigated by three-dimensional structure functions
such as generalized parton distributions (GPDs),
transverse-momentum-dependent parton distribution (TMDs),
and generalized distribution amplitudes (GDAs).
Here, we extract the GDAs, which are $s$-$t$ crossed quantities of
the GPDs, from cross-section measurements of
hadron-pair production process $\gamma \gamma^* \rightarrow h \bar h$.
The GPDs are expressed by a number of parameters and they are determined
from the hadron-pair production data. We discuss the dependence
on parton-momentum fraction $z$ in the GDAs and also time-like form factor.
Our studies should be valuable for probing the three-dimensional
structure of hadrons, especially for applications to
exotic hadron candidates which cannot be used as fixed targets
for GPD and TMD measurements.
