JLab Spin Experiments

1
JLab Spin Experiments

• Completed/on-going
• n (3He), both g1 and g2, 0.02 GeV2 lt Q2 lt 5 GeV2
• p/d, g1, 0.02 GeV2 lt Q2 lt 5 GeV2
• p/d, g2, Q21.3 GeV, 2 GeV2 lt Q2 lt 5 GeV2
• Spin experiments to be done at 6 GeV
• g2p at low Q2 (not practical with 12 GeV)
• g1d, constraint on DG
• Semi-SANE, flavor decomposition
• Transverse spin _at_ CLAS with HD

2
Neutron Spin Polarizabilities dLT Puzzle

• Significant disagreement between data and both
  ChPT calculations for dLTn
• g0n
  dLTn

E94-010, PRL 93 (2004) 152301
Q2

Q2

3
Proton g2 at low Q2
Polarized Proton Target
Septa Magnets for low Q2

• Critical input to Hydrogen Hyperfine Calculations
• Violation of BC Sum Rule suggested at large Q2
• State-of-Art ?PT calcs fail dramatically for ?LT

n
?LT Spin Polarizability
BC Sum Rule
4
Polarized Targets

• Polarized 3He good shape
• High polarization 35? 65
• Highest pol. lumi 1036
• Polarized NH3/ND3 targets
• Magnet, other hardware
• Performance, FOM
• Transverse polarization
• Polarized HD