Session #:  6

Author Name: Dustin E. McNulty

Title:  A Precise Measurement of the g2 Structure Function of the Proton
	and Deuteron

Institution:  University of Virginia

Email: dem4m@virginia.edu

Tel:  (804) 990-2613

Fax:  (804) 990-2617

Abstract:

A precision measurement of the deep inelastic polarized structure function 
g2 of the proton and deuteron has been made by the E155x collaboration in 
the ranges 0.02 < x < 0.9 and 1(GeV/c)2 < Q2 < 25(GeV/c)2.  The transverse 
physics asymmetry (Aperp) was measured at SLAC using 29.2 and 32.3 GeV 
longitudinally polarized electrons incident on transversely polarized target 
protons and deuterons; the scattered electrons were detected by three fixed 
angle spectrometers at 2.75, 5.5, and 10.5 degrees from the beam line.  
The g2 structure function was extracted using the measured Aperp, an E155 
fit to g1, and the most recent fits to world data on F2 and R.  The errors 
on g2 for both proton and deuteron are more than three times smaller than 
those of the previously existing world data set, thus enabling the data to 
resolve clearly between g2ww and zero as well as make distinctions between 
various models.