factorization studies with SIDIS A1p

1
factorization studies with SIDIS A1p
H.Avakian, P. Bosted, L. Elouadrhiri
SIDIS (gp-gtpX) x-section at leading twist
Structure functions FUU,FLL factorize into TMD
distributions (hep-ph 0405085)
Ji et al.
P- has contributions from distribution,
fragmentation and soft gluon radiation
2
Kinematic dependences of structure functions
S-Sudakov suppression factor, mL-scale
The A1p PT-dependence will be the same for
different Q2 at fixed x and z
3
AUL as a function of MX for p
Phys.Lett.B53585-92,2002
HERMES
Sign flip of exclusive SSA with the lepton charge?
4
A1p shows no significant Q2 and z dependence
ep ? e p X ( Ee 5.7 GeV, MX gt 1.1)
x0.727
A1p
x dependence of CLAS A1p (A20) consistent with
HERMES data and factorization.
5
PT-dependence
0.5ltzlt0.7
ltxgt0.727
A1p for Egt5GeV runs.
6
PT-dependence
Elt2.5GeV
ltxgt0.727
Elt2.3GeV
A1p for Egt5GeV runs doesnt show significant PT
dependence
7
z-dependence
A1p for Egt5GeV runs.
8
z-dependence
A1p for Egt5GeV runs doesnt show significant
z-dependence
9
summary

• A1p data from eg2000 is consistent with
  factorization
• A1p dependence on PT and z extracted for the
  first time

• Perform more detailed studies for different
  x/z/PT bins
• Check the r contamination
• Prepare an analysis note and a publication on A1p

10
Beam SSA sinf moment (CLAS _at_4.3 GeV)
ssinfLU FLUHLT 1/Q (Twist-3)
Beam SSA shows no significant dependence on W,E