Speaker
Description
Fragmentation functions describe the transition from asymptotically free, high energetic partons into final state hadrons. Since fragmentation functions are non-perturbative objects, they need to be measured experimentally. In particular electron-positron annihilation provides very clean input into fragmentation functions as no hadrons are involved in the initial state. The Belle experiment has provided various polarized and unpolarized fragmentation function measurements such as the single pion, kaon and proton cross sections, identified di-hadron cross sections in various topologies as well as transverse spin dependent asymmetries related to Collins and interference fragmentation functions. Several more measurements, including the intrinsic transverse momentum dependence are ongoing. The most recent results and the status of ongoing fragmentation function analysis will be presented.
