Status Report: JLAB Experiment E01-020 Hall A (e,e

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Status ReportJLAB Experiment E01-020 Hall
A(e,ep) Studies of the Deuteron at High Q2

• Luminita Coman
• Florida International University
• Spokespersons W. Boeglin, M. Jones, P. Ulmer,
  E. Voutier
• Ph.D. Students
• Luminita Coman - Florida International
  University
• Hassan Ibrahim - Old Dominion University -
  graduated

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Content

• Short introduction on (e,ep) reaction
• Kinematics and Cross Section review
• Performed Optimizations/Calibrations
• Applied cuts
• Cross section results for E01020 experiment
• RTL response function results
• Summary

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General Diagram of the 2H (e,ep)n Reaction
High momentum q(q0,q) is transferred to the
deuteron nucleus pm q-pf is the missing
momentum
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Kinematics

• q?(?,q) where ? e-e and qki-kf
• Pd(MD,0)
• Final state Pf(Ep,pf) and PR (En,pn)
• Q2 -q2 q2-?2 4e.esin2(?e/2)
• xBjorken variable Q2/m.??
• ??momentum conservation q Pd Pf PR
• x 1 - Tn/mn -2Tn??? q.pn/mn.?
• xgt1 gt PRq ltgt ?nq close to 00
• xlt1 gt pR-q ltgt ?nq close to 1800

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Theoretical Calculation
Glauber Approximation
General Eikonal Approximation
R

• Shows that relativistic kinematics are important
• The interaction is not instantaneous
• (the nucleons are at rest - GA)

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Optimizations/Calibrations

• Detector calibrations done
• optics, pointing,timing optimization
• Detector efficiency studies done
• VDC efficiency for Q2 3.5 GeV/c2 data
• Scintillator efficiency
• Cerenkov cut
• Luminosity studies done
• Stable beam analysis
• React_z dependence

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VDC efficiency for Q2 3.5 GeV/c2 data

• Cut on multiplicity in the 4 wire planes
• Lmult_uv12gt3. Lmult_uv12lt10.
• Tracks cuts Exactly one track
• Eff 1-track / (3-10) hits (in all planes)

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Scintillator Efficiencies

• Efficiency ()
• vs. Run number
• Electron arm
• Scintillator
• Efficiency
• S1 plane (blue)
• S2 plane (red)

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Determined Appropriate Cuts

• Cut on z difference abs(z_diff)lt0.015 m
• Cut on react_z abs(react_z) lt 0.05 m
• Fiducial cut -combined cut on E_miss, P_miss and
  Q2
• -10 ltE_misslt15 MeV, dp_miss 20 MeV, dQ2 0.25
  GeV/c2
• A software rectangular cut was applied at the
  focal plane
• R function cut R function was calculated for
  both experimental data and mceep and compared.
• Looked at the ratio between Rfn_exp to
  Rfn_mceep to determine in which range is linear
• R function cut 0ltrfnlt0.03

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R - function plot

• R function
• Kin e20
• Red -experimental
• Blue - mceep

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R - function plot

• R function
• Kin f50
• Red -experimental
• Blue - mceep

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R - function plot

• R function
• Kin f10l
• Red -experimental
• Blue - mceep

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R - function ratio experimental to mceep

• R function
• Kin d20

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Experimental Cross Section Results

• P_miss 200 MeV/c
• From right
• to left kinematics
• d20, e20, f20l, g20,h20
• Drawn with different
• marker styles

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Experimental Cross Section Results

• P_miss 400 MeV/c
• From right
• to left kinematics
• e40, f40l,g40, i40,j40
• Drawn with different
• marker styles

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Experimental Cross Section Results

• P_miss 500 MeV/c
• From right
• to left kinematics
• d50, f50, g50,j50
• Drawn with different
• marker styles

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Cross Section Results Experimental and Mceep
(Laget)

• P_miss 200 MeV/c
• Mceep -blue
• Experimental - red

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Cross Section Results Experimental and Mceep
(Laget)

• P_miss
• 400 MeV/c
• Mceep -blue
• Experimental - red

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Cross Section Results Experimental and Mceep
(Laget)

• P_miss
• 500 MeV/c
• Mceep -blue
• Experimental - red

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Summary

• Analysis of the RTL response functions finished
• Publication under way/thesis defended (Hassan)
• Mceep simulations done
• Results for angular distribution of the
  experimental cross sections close to final

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Summary