E08-005: A y 0 in Quasi-Elastic 3 He(e,e’n) Scattering Elena Long Hall A Collaboration Meeting December 17 th, /17/2013Hall A Collaboration MeetingElena Long

Today’s Discussion ◦ Brief background of the physics ◦ Experimental method ◦ Summary of past analysis ◦ Summary of recent analysis ◦ Results 12/17/ Hall A Collaboration MeetingElena Long

Simple 3 He(e,e’n) - PWIA ◦Ideally, the only interaction that occurs is when the incoming electron hits the neutron ◦This model is called Plane Wave Impulse Approximation (PWIA) ◦PWIA predicts the single-spin target asymmetry, A y 0, to be exactly zero 3 12/17/ He Hall A Collaboration MeetingElena Long

3 He(e,e’n) Complications ◦Since other nucleons exist in the 3He nucleus, they cause secondary effects that must be taken into account ◦These effects, particularly FSIs, cause A y 0 to be non-zero 12/17/ ◦Final State Interactions (FSI) ◦Meson Exchange Currents (MEC) Hall A Collaboration MeetingElena Long

Current Measurements ◦A y 0 data will test state-of-the-art calculations at high Q 2 ◦Neutron physics extracted from 3 He (such as EM form factors) must correctly predict this asymmetry ◦Any non-zero result indicates higher order effects 12/17/ Hall A Collaboration MeetingElena Long

Q 2 (GeV/c) 2 Ay0Ay0 Mod. PWIA [3] PWIA Historical Data and Models [1] H.R. Poolman, Ph.D. Thesis, Vrije Universiteit, [2] J. Bermuth et al., Phys. Lett. B564, 199 (2003). [3] J.M. Laget, Phys. Lett. B273, 367 (1991). [4] J. Golak et al., Phys. Rev. C65, (2002). 12/17/2013Hall A Collaboration MeetingElena Long 6 Q 2 (GeV/c) Ay0Ay0 Faddeev Calculations at 0.16 (GeV/c) 2 [1] Mod. PWIA [1] Mod. PWIA [1] Mod. PWIA [3] Q 2 (GeV/c) 2 Ay0Ay0 NIKHEF [1] Faddeev Calculations at 0.16 (GeV/c) 2 [1] Mod. PWIA [1] Mod. PWIA [1] Mod. PWIA [3] MAMI [2] Faddeev calculations by the Bochum group [4] correctly predicted FSI, where other groups expected a much lower value

The Measurement s 12/17/ Hall A Left HRS Right HRSBigBite ARC Compton Polarimeter Raster BCM eP Møller Polarimeter Polarized 3 He Target BPM Wire Chambers Trigger Plane (Scintillators) HAND Preshower Shower VDCs Q Q Q D Scintillators Gas Cerenkov Pion Rejectors (Pb Glass) Beam Dump D Hall A Collaboration MeetingElena Long

The Measurement s 3 He(e,e’n) Channel 12/17/ Hall A Collaboration MeetingElena Long h Incident Polarized Electron Scattered Electron θqθq γ* q -θ e’ pp n n e e

The Measurement s Experimental Set-up Run period was April- June /17/ Hall A Collaboration MeetingElena Long Right HRS Polarized 3 He Target HAND Standard Beamline Target Pol. Q 2 (GeV/c) 2 E 0 (GeV) RHRS (°) RHRS P 0 (GeV) HAND (°) Vertical Vertical Vertical

The Measurement s Polarized 3 He Target 12/17/ Hall A Collaboration MeetingElena Long Polarized 3 He Target

Pumping Chamber Target Chamber (Nuclear Physics Happens Here) The Measurement s 12/17/ Hall A Collaboration MeetingElena Long

The Measurement s Right HRS 12/17/ Hall A Collaboration MeetingElena Long Right HRS

The Measurement s Right HRS Detected scattered electrons from 3 He(e,e’n) and 3 He(e,e’) Provided trigger for HAND Detector package included VDCs, trigger scintillators, gas Cherenkov, and lead- glass calorimeters 12/17/ Hall A Collaboration MeetingElena Long Right HRS

The Measurement s Right HRS Detected scattered electrons from 3 He(e,e’n) and 3 He(e,e’) Provided trigger for HAND Detector package included VDCs, trigger scintillators, gas Cherenkov, and lead- glass calorimeters 12/17/ Hall A Collaboration MeetingElena Long Right HRS

The Measurement s 12/17/2013Hall A Collaboration MeetingElena Long 15 x sieve (m) y sieve (m) Right HRS Details in G. Jin, Ph.D. Thesis, University of Virginia, 2011

The Measurement s 12/17/2013Hall A Collaboration MeetingElena Long 16 Preshower/Shower Right HRS Electron ID Details in E. Long, Ph.D. Thesis, Kent State University, 2012 (arXiv: )

The Measurement s 12/17/2013Hall A Collaboration MeetingElena Long 17 Right HRS Electron ID Details in E. Long, Ph.D. Thesis, Kent State University, 2012 (arXiv: ) Bjorken x

The Measurement s 12/17/2013Hall A Collaboration MeetingElena Long 18 Right HRS 3 He(e,e’) Single-Spin Asymmetry Comparison with Y. Zhang 3 He(e,e’) SSA – Before Charge/LT Corrections χ 2 /dof=2.13 Preliminary

The Measurement s 12/17/2013Hall A Collaboration MeetingElena Long 19 Right HRS 3 He(e,e’) Single-Spin Asymmetry Comparison with Y. Zhang 3 He(e,e’) SSA – After Charge/LT Corrections χ 2 /dof=1.95 Preliminary

The Measurement s 12/17/2013Hall A Collaboration MeetingElena Long 20 Right HRS 3 He(e,e’) Single-Spin Asymmetry Comparison with Y. Zhang Q 2 =0.1 (GeV/c) 2 Q 2 =0.5 (GeV/c) 2 Q 2 =1.0 (GeV/c) 2 χ 2 /dof=1.95 χ 2 /dof=0.70χ 2 /dof=1.29 Preliminary

The Measurement s Hall A Neutron Detector (HAND) 12/17/ Hall A Collaboration MeetingElena Long HAND

The Measurement s Hall A Neutron Detector (HAND) 12/17/ Hall A Collaboration MeetingElena Long HAND

The Measurement s Hall A Neutron Detector (HAND) Plastic scintillator array Detected neutrons from 3 He(e,e’n) in coincidence with the RHRS Details in E. Long, Ph.D. Thesis, Kent State University, 2012 (arXiv: ) 12/17/ x 11 x 70 cm 3 10 x 10 x 100 cm 3 10 x 12.5 x 100 cm 3 10 x 15 x 100 cm 3 10 x 25 x 100 cm 3 Hall A Collaboration MeetingElena Long Front View Side View cm Stacking of scintillator bars in a plane n = 30 (plane 1) 24 (plane 2) 22 (plane 3) 12 (plane 4) Scintillator Light Guide 1 2 … … n PMT

The Measurement s Hall A Neutron Detector (HAND) Plastic scintillator array Detected neutrons from 3 He(e,e’n) in coincidence with the RHRS Details in E. Long, Ph.D. Thesis, Kent State University, 2012 (arXiv: ) 12/17/ Hall A Collaboration MeetingElena Long

The Measurement s Hall A Neutron Detector (HAND) Neutrons detected using veto method Details in E. Long, Ph.D. Thesis, Kent State University, 2012 (arXiv: ) 12/17/ p Hall A Collaboration MeetingElena Long

The Measurement s Hall A Neutron Detector (HAND) Neutrons detected using veto method Details in E. Long, Ph.D. Thesis, Kent State University, 2012 (arXiv: ) 12/17/ n Hall A Collaboration MeetingElena Long

p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p p The Measurement s Hall A Neutron Detector (HAND) Neutrons detected using veto method Details in E. Long, Ph.D. Thesis, Kent State University, 2012 (arXiv: ) 12/17/ n Hall A Collaboration MeetingElena Long p

The Measurement s Hall A Neutron Detector (HAND) Neutrons detected using veto method Details in E. Long, Ph.D. Thesis, Kent State University, 2012 (arXiv: ) 12/17/ Hall A Collaboration MeetingElena Long

The Measurement s Hall A Neutron Detector (HAND) Time-of-Flight background subtracted from the neutron peak Details in E. Long, Ph.D. Thesis, Kent State University, 2012 (arXiv: ) 12/17/ Hall A Collaboration MeetingElena Long Q 2 = 0.1 ToF Background Q 2 = 0.5 & 1.0 ToF Background Neutrons

The Measurement s Hall A Neutron Detector (HAND) Proton contamination Details in E. Long, Ph.D. Thesis, Kent State University, 2012 (arXiv: ) 12/17/2013Hall A Collaboration MeetingElena Long 30

The Measurement s Hall A Neutron Detector (HAND) Proton contamination Details in E. Long, Ph.D. Thesis, Kent State University, 2012 (arXiv: ) 12/17/2013Hall A Collaboration MeetingElena Long 31

Results 12/17/ Hall A Collaboration MeetingElena Long

Results Run-by-run A y 0 12/17/ Hall A Collaboration MeetingElena Long Q 2 =0.1 (GeV/c) 2 Q 2 =0.5 (GeV/c) 2 Q 2 =1.0 (GeV/c) 2 χ 2 /dof=0.517 χ 2 /dof=2.89χ 2 /dof=10.30 Preliminary

Results Run-by-run A y 0 12/17/ Hall A Collaboration MeetingElena Long Q 2 =0.1 (GeV/c) 2 Q 2 =0.5 (GeV/c) 2 Q 2 =1.0 (GeV/c) 2 χ 2 /dof=0.517 χ 2 /dof=1.0 Preliminary

Results Systematic Uncertainties 12/17/2013Hall A Collaboration MeetingElena Long 35

Results A y 0 vs. ν 12/17/2013Hall A Collaboration MeetingElena Long 36 Preliminary

Results A y 0 vs. Q 2 Linear 12/17/2013Hall A Collaboration MeetingElena Long 37 Preliminary

Results A y 0 vs. Q 2 Logarithmic 12/17/2013Hall A Collaboration MeetingElena Long 38 Preliminary

Thank you! 12/17/ Hall A Collaboration MeetingElena Long Graduate Students Spokespersons Run Coordinators Advisors

End 12/17/ Hall A Collaboration MeetingElena Long

Backup Slides 12/17/ Hall A Collaboration MeetingElena Long

The Measurement s 1] G. Jin, Ph.D. Thesis, University of Virginia, /17/2013Hall A Collaboration MeetingElena Long 42 Right HRS Electron ID Reaction Point in z

The Measurement s 12/17/2013Hall A Collaboration MeetingElena Long 43 Right HRS Electron ID Details in E. Long, Ph.D. Thesis, Kent State University, 2012 (arXiv: ) Cerenkov

The Measurement s 1] G. Jin, Ph.D. Thesis, University of Virginia, /17/2013Hall A Collaboration MeetingElena Long 44 Right HRS Electron ID Preshower/Shower

The Measurement s 1] G. Jin, Ph.D. Thesis, University of Virginia, /17/2013Hall A Collaboration MeetingElena Long 45 Right HRS Electron ID Theta/Phi

Simple 3 He(e,e’n) - PWIA ◦Ideally, the only interaction that occurs is when the incoming electron hits the neutron ◦This model is called Plane Wave Impulse Approximation (PWIA) ◦PWIA predicts the single-spin target asymmetry, A y 0, to be exactly zero 46 12/17/ He Hall A Collaboration MeetingElena Long

The Measurement s Hall A Neutron Detector (HAND) Proton contamination Details in E. Long, Ph.D. Thesis, Kent State University, 2012 (arXiv: ) 12/17/2013Hall A Collaboration MeetingElena Long 47

The Measurement s Reference Slide Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. 12/17/ Hall A Collaboration MeetingElena Long

Results A y 0 vs. Q 2 Linear and Logarithmic 12/17/2013Hall A Collaboration MeetingElena Long 49