Mon·Jun 29, 2009Monday·June 29, 2009

1. 01*

   The g2 Structure Function: An Experimental Overview

   K. Slifer🇺🇸

   We will discuss recent results for the spin structure functions, with an emphasis on g2 . High precision g2 data allows for tests of the Burkhardt-Cottingham sum rule, and is needed to consistently evaluate higher twist effects.

   nucl-exAIP Conf.Proc.(2009)·1 citation
2. 02*

   Low Q2 Measurement of g2p and the LT Spin Polarizability

   K. Slifer🇺🇸

   JLab has been at the forefront of a program to measure the nucleon spin-dependent structure functions over a wide kinematic range, and data of unprecedented quality has been extracted in all three experimental halls. Moments of these quantities have proven to be powerful tools to test QCD sum rules and provide benchmark tests of Lattice QCD and Chiral Perturbation Theory. Precision measurements of $g_{1,2}^n$ and $g_1^p$ have been performed as part of the highly successful `extended GDH program', but data on the $g_2^p$ structure function remain scarce. We discuss here JLab experiment E08-027, which will measure quantity $g_2^p$ in the resonance region at low $Q^2$. These data will be used to test the Burkhardt-Cottingham sum rule and to extract the higher moments ${\delta }_{LT}^p(Q^2)$ and ${\overline{d}}_2^p(Q^2)$. Data in the $Q^2$ range $0.02<Q^2<0.4$ GeV${}^2$ will provide unambiguous benchmark tests of $\chi$PT calculations on the lower end, while probing the transition region at the high $Q^2$ end where parton-like behaviour begins to emerge. This data will also have a significant impact on our theoretical understanding of the hyperfine structure of the proton, and reduce the systematic uncertainty of previous experiments which extracted the $g_1^p$ structure from purely longitudinal measurements.

   nucl-exAIP Conf.Proc.(2009)·4 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.