Speaker
Description
Heavy (bottom and charm) quarks are ideal probes of the nonperturbative dynamics of confinement because they effectively serve as static color sources during the entire hadronization cascade. In this talk, I discuss the transverse momentum-dependent (TMD) fragmentation functions (FFs) for heavy quarks fragmenting into heavy hadrons as powerful tools for probing heavy-quark fragmentation in depth. I identify novel nonperturbative TMD matrix elements in heavy-quark effective theory (HQET) and present new TMD sum rules that arise from heavy-quark spin symmetry. These results lead to a rich phenomenology, especially for the heavy-quark Collins effect, at existing $B$ factories. In addition, I calculate all TMD parton distribution functions (PDFs) for the production of heavy quarks from polarized gluons within the nucleon and demonstrate the potential of the future EIC to resolve TMD heavy-quark fragmentation in semi-inclusive DIS.
