Session H4: Hadronic Physics

Comparison of the F2 Structure Function in Iron as Measured by Charged Lepton and Neutrino Probes

World data for the structure function $F_{2}$ for Iron from charged lepton and neutrino scattering experiments are compared. The observations cleanly underscore previously observed hints of a difference in the behavior of the data between charged lepton and neutrino scattering, notably in the anti-shadowing region where the Bjorken scaling variable $x$ is below 0.15. The charged lepton data appear to undergo shadowing/anti-shadowing whereas the neutrino data seem to exhibit no nuclear effects. Moreover, we find very good agreement between the different types of probes in the $x$ region above 0.15. Details and results of the data comparison are shown in this talk.   

Large-x Structure Function Data from Jefferson Lab

An overview of the structure function data taken at Jefferson Lab (JLab), which is predominently in the large Bjorken-x region, $ 0.3 < x_{B} < 0.7$, is presented. This region of phase-space has been previously somewhat unexplored. Including the JLab data along with available world data has allowed an extraction of the lowest three moments of the proton structure function. Comparison of this analysis with several Parton Distribution Function (PDF) parametrizations is discussed. Structure function ratio data from the BoNuS experiment at JLab has also had an impact in verifying the methods used in producing PDFs from global fits to world data by the CTEQ-JLab (CJ) collaboration. The use of the JLab data in the CJ effort will be described in more detail.   

Measuring the Transverse Proton Structure with SoLID

The Solenoidal Large Intensity Device (SoLID) has been proposed in Hall A at Jefferson Lab, which will fully utilize the great physics potential of the 12-GeV energy upgrade by combining high luminosities and large acceptance. Three of five highly-rated approved experiments are the semi-inclusive deep inelastic scatterings (SIDIS) of 11 GeV and 8.8 GeV electron beams on transversely and longitudinally polarized helium-3 targets and a transversely polarized proton target with the detection of charged pions and electrons in coincidence to study the transverse momentum dependent parton distributions (TMDs). The SoLID SIDIS experiment will provide 4D $(x, z, Q^2, P_T)$ mappings of the azimuthal asymmetries in the valence quark region with high precision. In this talk, we take the Collins asymmetry as an example to show the SoLID impacts on the extraction of the transversity distributions and the tensor charges. We develop a simple strategy based on the Hessian matrix analysis that allows one to estimate the uncertainties of the transversity distributions and the tensor charges extracted from SoLID data simulation. We find that the SoLID measurements with proton and effective neutron targets will improve the precision of u and d quark transversity distributions and tensor charges up to one order of magnitude.