Deuterium Measurement in Nucleon Resonance Region

1. Experiment Rosen07: Measurement of R = sL / sT on Deuterium in the Nucleon Resonance Region. • Physics • Data Analysis • Cross Section calculation • L/T Separations Ibrahim H. Albayrak Hampton University

2. ROSEN07 and JAN05 experiments • ROSEN07 (E06-009) is the second phase of the experiment JAN05(E04-001) with higher Q2 data. • ROSEN07 is combination of two experiments: • Measurement ofR = sL / sT on Deuterium in the Nucleon Resonance Region.(I.Albayrak) • Measurement ofR = sL / sT on Nuclear targets in the Nucleon Resonance Region.(VaheMamyan) • JAN05 is combination of two experiments: • Measurement ofR = sL / sT on Deuterium in the Nucleon Resonance Region.(YaLi) • Measurement ofR = sL / sT on Nuclear targets in the Nucleon Resonance Region.(YaLi)

3. Physics Physics Motivation • FL, F1, F2 and R fundamental Structure Function Measurements on Deuterium. - These structure functions provide us important information about internal structure of nucleon, i. e. distribution of quarks and gluons inside the nucleus. • Since these are fundamental measurements, they allow a variety of physics issues to be addressed, such as: • Structure Function Moments • Lattice QCD comparisons • Singlet and non-singlet distribution functions • Quark-hadron duality studies Deuterium/neutron • Support Broad Range of Deuteron Physics • Spin structure functions • BONUS (BOund NUcleon Structure) neutron structure functions - Hall B experiment for NEUTRON cross sections via spectator tagging.

4. Physics Calculable in Quantum Electrodynamics (QED) Physics of Interest (Nucleon Structure) Structure Functions: F1, F2, FL { Structure functions (F1 and F2) which have the Information of the nucleon’s internal structure.

5. Physics Transverse longitudinal Rosenbluth Separation Technique: Where:  = flux of transversely polarized virtual photons  = relative longitudinal flux

6. Physics Moments of the Structure Functions • Cornwall-Norton moments of the SFs are defined as • M11 gives the quark charges. • M22 gives the total momentum of the quarks.

7. Physics Moments of the Structure Functions Md – 2Mp = ∫xn-2 (Fd∙f – 2Fp)dx yields non-singlet distribution • The non-singlet moments can only be determined from differences of proton and neutron moments. • Assuming a charge-symmetric sea, n-p isolates the non-singlet • Where • Need to pin down non-singlet (n-p) to extract singlet . • Moments Calculated on the lattice at Q2 = 4 GeV2

8. Physics Purely New data with high Q2 above 3 GeV New data with higher Q2 And new epsilon points for LT separation ROSEN07 JAN05 ROSEN07 experiment is the second phase of this experiment, the first phase was JAN05 experiment…

9. Experiment & Data analysis Current Status and Update • Detector Calibrations • Kinematic Corrections • Dead Times • Efficiencies • Background Estimation and Subtraction: • Target Density Correction • Acceptance Corrections • Bin-centering corrections • Radiative corrections • Iteration Procedure • Systematic Uncertainties • Extracting Differential Cross Sections • Doing Rosenbluth L/T Separation • Moment extraction • N-p analysis

10. Experiment & Data analysis Data to Monte Carlo simulation comparisons…

11. Experiment & Data analysis Drift Chamber Positions Offsets Significantly different from previous data!!! Checked optics elements, magnets fields, matrix elements and no difference found from previous data. Could it be because of DC offsets?

12. Experiment & Data analysis Offsets for Drift Chamber Positions After putting the relative offset 0.45 mm for Y position we get better comparison! Before After After correction y pos gets narrow, which indicates that we are doing the right thing.

13. Experiment & Data analysis Offsets for Drift Chamber Positions Even after putting the DC offset, there is still a shape difference at low E’ region! Before After Using alternative Cosy marix elements in the analyzer at low E’ at the edge of the acceptance removes the most of the discrepancy!

14. Experiment & Data analysis Cross Sections Extraction Method Monte Carlo ratio method is used to extract data cross sections: We can simulate Monte Carlo data using a cross section model to obtain And yield for the data can be written as: Taking ratio to data and assuming that AMC = A, yields Peter Bosted and Eric Christy’s deuterium fit parameterization used as the input model. And this data has helped in the development of this model.

15. Experiment & Data analysis Representative Sample Cross Sections

16. Experiment & Data analysis Representative Sample Cross Sections

17. Experiment & Data analysis Representative Sample Cross Sections

18. Experiment & Data analysis And L/T Separations… • Here is some almost final Rosenbluth separation plots for 3 different W2, Q2 pairs

19. Experiment & Data analysis Structure Functions (Preliminary) Structure functions F2 and FL at Q2 = 2 GeV. Quasielasticcontribution shown by red line.

20. Experiment & Data analysis Structure Functions (Preliminary) Structure functions F2 and FL at Q2 = 2 GeV (quasielastic contribution subtracted). Quasielastic contribution subtracted (not completely?).

21. Experiment & Data analysis Methodology of extraction of moments of Structure Functions

22. Experiment & Data analysis Moments of the Structure Functions (Preliminary) Rosen07 F2 data is combined with the previous data from SLAC and NMC.

23. Experiment & Data analysis Moments of the Structure Functions (Preliminary) n=2,4 and 6 moments of the structure function F2 at Q2 = 2 GeV.

24. Experiment & Data analysis Moments of the Structure Functions (Preliminary) n=2,4 and 6 moments of the structure function F2 at Q2 = 4 GeV.

25. Experiment & Data analysis Summary • Calibrations have been done. • Charge symmetric background subtraction, radiative corrections and other corrections have been done. • Preliminary L/T separations have already been done. • Structure functions R, F1, F2 and FL have been extracted (preliminary) • Moments of the structure functions extracted (preliminary) • What is left: n-p analysis