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Motivations. Understand transition between partons and hadrons Study of higher twists Spin and flavor dependence of quark-hadron duality Access high x bj region if duality is demonstrated and well understood. Hint of duality. The E01-012 experiment.
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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 P. Solvignon, Duality Workshop
Hint of duality P. Solvignon, Duality Workshop
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-sections differences and asymmetries • Form g1, g2, A1 andA2 for 3He • Test duality on the neutron SSF P. Solvignon, Duality Workshop
The experimental setup JLab HALL A • Polarized e- beam at 3, 4 and 5 GeV; Pavg =(773)% • Both HRS in symmetric config. at 25o and 32o: Double statistics Control systematics • PID= Cerenkov + EM calo. /e reduced by 104(e-)>99% P. Solvignon, Duality Workshop
Polarized 3He target Spin exchange between optically pumped Rb and 3He • Longitudinal and transverse configurations • High luminosity: 1036 s-1 cm-2 • 2 independent polarimetries: NMR and EPR P. Solvignon, Duality Workshop
Data analysis - - A//raw = A raw= + + • Generate asymmetries: • Measure unpolarized cross section: • Form polarized cross sections differences: • Can also get Born asymmetries: oborn = oraw- 2(N2/3He)N + R.C. //()raw = 2 A//()o //() = //()raw + R.C. A//()= //() / 2oborn P. Solvignon, Duality Workshop
Polarized structure functions Extract g1 and g2 directly from our data MQ2 E 1 g1 = 4e2 E´ E +E´ (//+ tan(/2) ) (- //+ MQ22 1 g2= 4e2 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, Duality Workshop
Elastic asymmetry P. Solvignon, Duality Workshop
Asymmetries P. Solvignon, Duality Workshop
Comparison of both HRS P. Solvignon, Duality Workshop
Unpolarized cross sections P. Solvignon, Duality Workshop
Polarized structure function g1 P. Solvignon, Duality Workshop
Polarized structure function g1 P. Solvignon, Duality Workshop
Polarized structure function g1 P. Solvignon, Duality Workshop
Polarized structure function g1 P. Solvignon, Duality Workshop
Polarized structure function g1 P. Solvignon, Duality Workshop
Spin asymmetry A1 P. Solvignon, Duality Workshop
Spin asymmetry A1 P. Solvignon, Duality Workshop
Spin asymmetry A1 P. Solvignon, Duality Workshop
Spin asymmetry A1 P. Solvignon, Duality Workshop
Spin asymmetry A1 P. Solvignon, Duality Workshop
Spin asymmetry A2 P. Solvignon, Duality Workshop
Conclusion • E01-012 provides precision data of SSF on neutron (3He) for 1.0 < Q2 < 4.0 (GeV/c) 2 • Direct extraction of g1 andg2 from our data • Overlap between E01-012 resonance data and DIS test of Quark-hadron duality for neutron and nuclei SSF • E01-012 data combined with proton data test of spin-flavor dependence of duality • Our data can also be used to extract moments of SSF (e.g. GDH sum rule, d2, BC sum rule) P. Solvignon, Duality Workshop
Outlook Extraction of the neutron SSF Final results by the end of 2005 P. Solvignon, Duality Workshop
Polarized structure function g2 P. Solvignon, Duality Workshop
Spin asymmetry A1 P. Solvignon, Duality Workshop