Speaker
Description
We report preliminary results on semi-inclusive target- and double-spin asymmetries where a proton is detected in the target-fragmentation region (TFR) in coincidence with the scattered electron. Compared to the current fragmentation region (CFR), where final state hadrons are produced by the struck quark, the TFR, where hadrons form out of the fragmenting spectator partons, is relatively little studied. The study of the formation of hadrons out of the target remnant can provide critical information on nucleonic structure and the process of hadronization through objects called fracture functions. Fracture functions are the TFR analog of the parton distribution functions defined in the CFR and, at leading twist, have the probabilistic interpretation of forming a specific hadron from a fragmenting nucleon after the emission of a particular quark. The data were taken with a 10 GeV longitudinally polarized electron beam incident on a longitudinally polarized NH$_3$ target using the CLAS12 Spectrometer in Hall B of Jefferson Lab. These data represent the first signifiant opportunity to measure structure functions such as $F_{UL}$, $F_{LL}$ and others in the TFR and provide the possibility of mapping out the transition between both regions of kinematic origin as well as serving as a test of the fracture function formalism by linking the observed fracture function-dependent quantities to the more traditional CFR observables through momentum sum rules.
