E01-012 : Spin-Duality Analysis update

1. E01-012 : Spin-DualityAnalysis update Patricia Solvignon Temple University, Philadelphia Hall A Collaboration Meeting, June 23-24, 2005

2. Duality in unpolarized structure functions Hall C results P. Solvignon, Hall A Collab. Meeting I. Niculescu et al., Phys. Rev. Lett. 85 (2000) 1182

3. Motivations • Understand transition between partons and hadrons • Study of higher twists • Spin and flavor dependence of quark-hadron duality • Access high xbj region if duality is demonstrated and well understood X. Zheng et al., Phys. Rev. Lett. 92 (2004) 012004 P. Solvignon, Hall A Collab. Meeting

4. Hint of duality E94-010saw a hint of duality in g1(3He) Figure from Seonho Choi P. Solvignon, Hall A Collab. Meeting

5. The E01-012 experiment Spokepeople: N. Liyanage, J-P. Chen, Seonho Choi Graduate Student: P. Solvignon • Ran in January-February 2003 • Inclusive experiment: 3He(e,e’)X • Measured polarized cross-sectionsdifferences and asymmetries • Form g1, g2, A1 andA2 for 3He   Test duality on the neutron SSF P. Solvignon, Hall A Collab. Meeting

6. Data analysis Generate asymmetries and unpolarized cross sections (N+/Q+ LT+)-(N-/Q- LT-) A/ / ()raw=  (N+/Q+ LT+)+(N-/Q- LT-) Ncut Ntrial oraw =   Ninc 3Hedet LT Nacc Ltarg p  P. Solvignon, Hall A Collab. Meeting

7. Data analysis Apply correction for nitrogen dilution A/ / () exp= A/ / ()raw /(fN2Ptarg Pbeam) oexp = oraw- 2(N2/3He)N P. Solvignon, Hall A Collab. Meeting

8. Data analysis Form polarized cross section differences //() exp= 2 A //()expoexp Apply radiative corrections on //() and o //()= //() exp + R.C. A//()= //() / 2oborn P. Solvignon, Hall A Collab. Meeting

9. Analysis update Target • Density evaluated for each run • EPR analysis almost done • NMR analysis completed (V. Sulkosky) Cross sections and asymmetries • Detector efficiencies done • Nitrogen dilution done • 1st pass radiative corrections Preliminary results on 3He spin structure functions P. Solvignon, Hall A Collab. Meeting

10. Target performance Pavg= 37% P. Solvignon, Hall A Collab. Meeting

11. Density check: perp vs. para Running with Duke Running with Exodus P. Solvignon, Hall A Collab. Meeting

12. HRS cross sections comparison Agreement between left and right arms cross sections is at 2% level. P. Solvignon, Hall A Collab. Meeting

13. Nitrogen cross sections QFS model from J.W. Lightbody and J.S. O’Connell P. Solvignon, Hall A Collab. Meeting

14. Radiative corrections • Elastic tail negligeable at all our kinematics • For 1st pass, used QFS as model for o • Used E94-010 spin structure functions as a model for the radiative corrections on //() for our lowest energy • Then used our own data P. Solvignon, Hall A Collab. Meeting

15. Asymmetries N2 dilution applied and 1st pass radiative corrections P. Solvignon, Hall A Collab. Meeting

16. Unpolarized cross sections before R.C. raw with both arms combined exp= raw - N N corrected for density ratio P. Solvignon, Hall A Collab. Meeting

17. Unpolarized Born cross sections After R.C., we obtain born Smoothed exp P. Solvignon, Hall A Collab. Meeting

18. Polarized structure functions Extract g1 and g2 directly from our data MQ2 E 1 g1 =    4e2 E´ E +E´ (//+ tan(/2) ) (- //+ MQ22 1 g2=   4e2 2E´(E +E´) E + E´ cos  E´sin ) Need external input of R to form A1 and A2 A// A A1 =  -  D(1+) d(1+)  A//A A2 =  +  D(1+) d(1+) (D and d depend of R) P. Solvignon, Hall A Collab. Meeting

19. Polarized structure function g1 DIS fit : no Q2-evolution included here P. Solvignon, Hall A Collab. Meeting

20. Polarized structure function g1 Large negative contribution of (1232) P. Solvignon, Hall A Collab. Meeting

21. Polarized structure function g1 Still large negative contribution of (1232). But, at lower x, resonance data seem to oscillate around the DIS curve. P. Solvignon, Hall A Collab. Meeting

22. Polarized structure function g1 The (1232) disappears and the resonance data seems to approach the DIS behavior. P. Solvignon, Hall A Collab. Meeting

23. Polarized structure function g1 No resonance structure can be seen anymore. P. Solvignon, Hall A Collab. Meeting

24. Spin asymmetry A1 DIS data on 3He P. Solvignon, Hall A Collab. Meeting

25. Spin asymmetry A1 A1 is large and negative in the (1232) region. P. Solvignon, Hall A Collab. Meeting

26. Spin asymmetry A1 A1 is still negative in the (1232) region. P. Solvignon, Hall A Collab. Meeting

27. Spin asymmetry A1 The (1232) vanishes while the non-resonant background is rising. A1 becomes positive in the (1232) region. P. Solvignon, Hall A Collab. Meeting

28. Spin asymmetry A1 The two highest Q2 data sets agree with each other and show the same trend as DIS data. P. Solvignon, Hall A Collab. Meeting

29. Spin asymmetry A2 P. Solvignon, Hall A Collab. Meeting

30. Still to do • Finalize target analysis • 2nd pass radiative corrections • Extract the neutron spin structure functions • Extract moments of structure functions (e.g. GDH sum rule, BC sum rule) Final results expected by the end of 2005 P. Solvignon, Hall A Collab. Meeting

31. Extra slides

32. Polarized structure function g2 P. Solvignon, Hall A Collab. Meeting

33. Elastic tail P. Solvignon, Hall A Collab. Meeting

34. Target density P. Solvignon, Hall A Collab. Meeting