Speaker
Description
The polarized target program in Hall D at Jefferson Lab, which began to measure the Gerasimov-Drell-Hearn (GDH) integrand on hydrogen and deuterium, presents a unique opportunity for nuclear physics with a photon probe. The polarized target apparatus will allow polarization observables to be measured with a photon beam on polarized nuclei such as Li-7, C-13, N-15, O-17, and F-19 with photon energies up to 12 GeV. This data would allow the measurement of the GDH integrand of a nucleon in the nucleus which may allow the extraction of information on nuclear medium modifications [Bass20, Bass22]. As an inclusive measurement this would have a statistical advantage over many methods of probing nuclear modifications. It is reported that short range correlations will depolarize the paired nucleons [Thomas18] so that a change of the structure function of a high momentum, far off-mass-shell nucleon in a correlated pair, can only lead to very small EMC effect on the nuclear spin structure function. This can be tested by studying target spin asymmetries as a function of the relative momentum between two correlated nucleons, particularly in the region above the Fermi momentum.
[Bass20] https://doi.org/10.5506/APhysPolB.52.43
[Bass22] https://doi.org/10.48550/arXiv.2212.04795
[Thomas18] https://doi.org/10.1142/S0218301318400013 International Journal of Modern Physics EVol. 27, No. 12, 1840001 (2018)
