Speaker
Description
The precise mechanism underlying spin-flavor symmetry breaking in QCD is unknown but is illuminated by the behavior of high momentum quarks in the nucleon. Conventionally, high partons have been studied by extracting the neutron-to-proton structure function ratio via fits to nuclear DIS data. However, these fits rely on model-dependent, theoretical descriptions of nuclear effects.
The quark PDF ratio () also probes the symmetry breaking mechanism and can be extracted experimentally using semi-inclusive DIS (SIDIS). In SIDIS, the hadronization products are measured in coincidence with the scattered lepton in DIS reactions, giving access to the struck quark’s flavor. Nucleus-independent fragmentation functions connect the flavor of the struck quark to the flavor composition of the produced hadron and are essential to the experimental determination of .
We present a measurement of the pion unfavored-to-favored fragmentation function ratio extracted from data acquired at CLAS12 at electron beam energies of 10.2, 10.4, and 10.6 GeV with a deuterium target. This data’s wide kinematic range has allowed us to map the fragmentation function ratio as a function of and , providing insight into the evolution of the hadronization process with respect to probe resolution and initial quark dynamics.
