Faithin Omaha eBook Collection

Download or read book An Overview of Longitudinal Spin Structure Measurements from JLab written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Jefferson Lab is currently one of the facilities leading the investigation of the spin structure of the nucleon. Over the past 15 years, several high precision measurements have been completed, extending our knowledge of the polarized structure functions g1 and g2 down to Q2 = 0.02 GeV2. In particular, the low-Q2 range (≤ 0.1 GeV2) from these data allows us to make a benchmark-check of Chiral Perturbation theory ([chi]PT). Previous results for the moments of the spin structure functions in this region have shown mixed agreement. For [Gamma]1, the first moment of g1, we find good consistency between data and theory. However, we have seen a surprisingly large discrepancy with [chi]PT calculations for the [delta]{sub LT} spin polarizability on the neutron, which is significantly less sensitive to the [Delta]-resonance contribution. These proceedings will discuss the recent experimental effort at low Q2 from Jefferson Lab, including a discussion of preliminary results on the neutron. The new results on the neutron still show a sizeable discrepancy between data and theory. However, new calculations show improved agreement with data for some observables. In addition, new proton data for g2 is also expected to help resolve the disagreement for [delta]{sub LT}.