, Old Dominion University
[Host: Blaine Norum]
Double spin asymmetries for the proton and the deuteron have been
measured in the EG1b experiment using the CLAS detector at Jefferson
Lab. Longitudinally polarized electrons at energies 1.6, 2.5, 4.2 and 5.7
GeV were scattered from longitudinally polarized NH 3 and ND 3 targets.
The double spin asymmetry Ak has been extracted from these data as a
function of Q 2 and W with unprecedented precision. The virtual photon
asymmetry A 1 and the spin structure function g 1 can be calculated from
these measurements by using parameterizations to the world data for the
virtual photon asymmetry A 2 and the unpolarized structure functions
F 1 and R. The large kinematic coverage of the experiment (0.05 GeV 2
< Q 2 < 5.0 GeV 2 and 1.08 GeV < W < 3.0 GeV) helps us to better
understand the spin structure of the nucleon, especially in the transition
region between hadronic and quark-gluon degrees of freedom. The results
from EG1b combined with other experiments provide a good description of
the virtual photon asymmetries making their parameterizations possible
in a large kinematic range. In this talk, the results on A 1 , g 1 and the first
moment Γ 1 1
of the deuteron will be presented. The parametrization efforts
on the asymmetries and the spin structure functions will be discussed. The
neutron spin structure function, extracted from the combined proton and
deuteron data, will be shown.
Nuclear Physics Seminar
Tuesday, February 16, 2010
Physics Building, Room 204
Note special room.
To add a speaker, send an email to
Please include the seminar type (e.g. Nuclear Physics Seminars), date, name of the speaker, title of talk, and an abstract (if available).