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Spectroscopic Factors and A TL from Quasielastic (e,e'p) Reaction in 208 Pb, 12 C and 16 O at JLab J.L. Herraiz 1, J.M. Udías 1 J.C. Cornejo 2, A. Camsonne.

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Presentation on theme: "Spectroscopic Factors and A TL from Quasielastic (e,e'p) Reaction in 208 Pb, 12 C and 16 O at JLab J.L. Herraiz 1, J.M. Udías 1 J.C. Cornejo 2, A. Camsonne."— Presentation transcript:

1 Spectroscopic Factors and A TL from Quasielastic (e,e'p) Reaction in 208 Pb, 12 C and 16 O at JLab J.L. Herraiz 1, J.M. Udías 1 J.C. Cornejo 2, A. Camsonne 3, A. Saha 3, K. Aniol 4, G.M. Urciuoli 5 L.B. Weinstein 6, K.G. Fissum 7 and the Hall A collaboration 1 Universidad Complutense, Madrid, Spain 2 The College of Williams and Mary, VA, USA 3 Thomas Jefferson National Accelerator Facility, Newport News, VA, USA 4 California State University, Los Angeles, California, USA 5 INFN, Sezione di Roma, Rome, Italy 6 Old Dominion University, VA, USA 7 Lund University, Sweden

2 1) QUASIELASTIC (e,ep) REACTION 1) QUASIELASTIC (e,ep) REACTION 2) SIMULATIONS 3) DESCRIPTION OF THE EXPERIMENT 4) DATA ANALYSIS 5) RESULTS 6) SUMMARY AND CONCLUSIONS 2

3 Unpolarized electron beams with an Energy of several GeV. Typical targets are doubly- magic, closed-shell nucleus like 16 O, 208 Pb. Their bound-nucleon wave functions are well known and relatively easy to calculate. The scattered electron is detected in coincidence with an ejected proton. The three-momentum of these particles are measured and based on this information we obtain the properties of the proton in the nucleus. Quasielastic A(e,ep)B Experiments 1 ) QUASIELASTIC (e,ep) REACTION 2 ) DESCRIPTION OF THE EXPERIMENTS 3 ) SIMULATION 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 3

4 Kinematics (e,ep) reaction in the Born Approximation Incident Electron Scattered Electron Ejected Proton Residual Nucleus Virtual Photon 1 ) QUASIELASTIC (e,ep) REACTION 2 ) DESCRIPTION OF THE EXPERIMENTS 3 ) SIMULATION 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 4 Exclusive conditions Unpolarized particles

5 Simple Description of the (e,ep) Reaction Single-photon Exchange and Impulse Approximation (IA) Mean-Field and Independent Particle Shell Model (IPSM) Plane-Waves (PWIA) Measured Cross Section Kin. Factor electron- proton Cross Section Spectral Function Probability of finding a proton in the nucleus with binding energy E miss and momentum p miss. 1 ) QUASIELASTIC (e,ep) REACTION 2 ) DESCRIPTION OF THE EXPERIMENTS 3 ) SIMULATION 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 5 MeV E miss (MeV) S(E miss,p miss )[MeV] -1 (GeV/c) -3

6 Other Effects in the (e,ep) Reaction A more accurate description of the (e,ep) reaction includes: Final-State Interactions: Interactions of the extracted proton with the residual nucleus. This is modeled by an optical potential from elastic (p,p) data. Proton is described by Distorted Waves (DWIA). Coulomb Distortion and Internal Radiative Corrections: The momentum of the electrons at the reaction point is different to their asymptotic measured values. External Effects (From atomic interactions in the target) Energy Loss, External Radiative Corrections, Straggling, Proton Absorption. 1 ) QUASIELASTIC (e,ep) REACTION 2 ) DESCRIPTION OF THE EXPERIMENTS 3 ) SIMULATION 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 6

7 For a E miss peak (shell) Reduced cross-section (Distorted Momentum Distribution) Spectroscopic Factors – Scale factor required to fit the simulated reduced cross section with the measured one. (e,ep) Observables 1 ) QUASIELASTIC (e,ep) REACTION 2 ) DESCRIPTION OF THE EXPERIMENTS 3 ) SIMULATION 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 7 Transverse-longitudinal assymetry (A TL ) q kiki kfkf p p miss < 0 p p miss > 0

8 1) Momentum Distribution of protons – Measurement of the reduced cross section for different shells in the nucleus in a large p miss range. Search for correlation effects at high p miss. 208 Pb is one of the best nucleus to observe these effects. Objectives of this (e,ep) Experiment (I) 1 ) QUASIELASTIC (e,ep) REACTION 2 ) DESCRIPTION OF THE EXPERIMENTS 3 ) SIMULATION 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS With correlations Without correlations p miss (MeV/c) Cross Section 208 Pb(e,ep ) Valence States 8

9 2) Spectroscopic Factors - Deviation from the mean field occupation prediction expected for each shell in the Shell Model. It is obtained as the factor required to fit theoretical calculations to measured data. It was argued that there could be a dependence of spectroscopic factors with Q 2. Objectives of this (e,ep) Experiment (II) 1 ) QUASIELASTIC (e,ep) REACTION 2 ) DESCRIPTION OF THE EXPERIMENTS 3 ) SIMULATION 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS In this work this possible dependence was studied in two different nucleus: 12 C and 208 Pb, obtaining the spectroscopic factor at three different Q 2 values: 0.8, 1.4 and 2.0 (GeV/c) 2. 9

10 3) Dynamical Relativistic Effects – Enhancement of the lower components of the proton spinor inside the nucleus. Relativistic DWIA: Nucleon current computed with a fully relativistic operator. The wave functions are four- component spinor solutions of the Dirac equation with scalar and vector potentials and their lower components are dynamically enhanced with respect to a solution of Dirac equation without potentials (a free spinor). 1 ) QUASIELASTIC (e,ep) REACTION 2 ) DESCRIPTION OF THE EXPERIMENTS 3 ) SIMULATION 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS The effect of spinor distortions is visible in A TL observable. This was seen in a previous Jlab experiment for the 1p 1/2 shell in 16 O, whose (relativistic) lower component is a 1s 1/2 shell Objectives of this (e,ep) Experiment (III) 10

11 2) SIMULATIONS 1) QUASIELASTIC (e,ep) REACTION 2) SIMULATIONS 3) DESCRIPTION OF THE EXPERIMENT 4) DATA ANALYSIS 5) RESULTS 6) SUMMARY AND CONCLUSIONS 11

12 Spectrometer Acceptances THEORETICAL CALCULATIONS: Assume central values for the spectrometer acceptances EXPERIMENTS: Spectrometers with significant angular and momentum acceptances 1) Acceptance effects may be removed from data via stringent cuts (statistics suffer). 2)Assuming factorization, acceptances effects can be removed via reduced cross section and significant cuts. 3)Calculations may be averaged over acceptance (requires combination of theory and simulation) ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS

13 MCEEP MCEEP (Monte Carlo for (e,ep) experiments) is a simulation open source code written in Fortran. It was designed to simulate coincidence (e,eX) experiments by averaging theoretical models over the experimental acceptances. MCEEP employs a uniform random sampling method to populate the experimental acceptance. It has an important limitation: it uses very simple models of the (e,ep) reaction to avoid long computational time. MCEEP V3.9 (June 2006) P. E. Ulmer et al. eep.html 13 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS

14 MCEEP + DWIA In an extended-acceptance experiment, each event can correspond to somewhat different kinematics. Evaluating the cross section with the DWIA code for each event simulated with MCEEP requires too much time. In our approach the Response Functions (R L,R T,R LT,R TT ), which contain the information of the nuclear charge and current densities, are precomputed in a grid (E miss, p miss,q, ) which spans the experimental phase space. After that, we interpolate within this grid in MCEEP for extracting the cross section on an event-by-event basis. Radiation effects are included in MCEEP simulations than thus can be directly compared to data ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS

15 Theory: Ingredients 208 Pb 12 C 16 O Bound-nucleon wave function HSNLSHNLSH-P Optical model EDAI-PBEDAI-CEDAI-O Nuclear spinor distortion Relativistic and non-relativistic (projected) Electron distortion(Can be included in simulation) KinematicsRelativistic Current operatorCC2 Nucleon form factorsRosenbluth data fit GaugeCoulomb 15 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS

16 3) DESCRIPTION OF THE EXPERIMENT 1) QUASIELASTIC (e,ep) REACTION 2) SIMULATION 3) DESCRIPTION OF THE EXPERIMENT 4) DATA ANALYSIS 5) RESULTS 6) SUMMARY AND CONCLUSIONS 16

17 Experiment E O(e,ep) Data acquisition October-December, 2001 Requirements Luminosity from H(e,e) Contamination from H(e,ep) events Low p miss region not available. A continuation of experiment E89-003, which measured 16 O(e,ep)N cross section using a waterfall target. In this experiment, the cross section was measured in the quasielastic peak (Q 2 =0.9GeV 2, =0.5GeV) with a larger missing momentum range and much higher precision. 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATION 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 17 p miss (MeV/c)

18 We measured 208 Pb(e,ep) 207 Tl and 209 Bi(e,ep) 208 Pb cross sections at true quasielastic kinem. (x B = 1, q = 1 GeV/c, ω = GeV/c) and at both sides of q. This has never been done before for A>16 nucleus. Additionally we measured 12 C(e,ep) as a reference. Data acquisition RUN 1 – (March, 3-26, 2007) RUN 2 – (January 2008) Requirements Good Energy Resolution Rastered Beam & Composed Target (Diamond+Pb+Diamond) With correlations Without correlations 18 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATION 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS Experiment E Pb(e,ep), 209 Bi(e,ep) & 12 C(e,ep)

19 Experimental Setup and Kinematics ELECTRON SPECTROMET ER PROTON SPECTROME TER BEAM LINE TARGET CHAMBER Q1Q2 DIPOLE Q ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATION 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS JLAB - Hall A

20 Experimental Setup: 4. - Kinematics 208 Pb(e,ep) and 12 C(e,ep) 16 O(e,ep) 20 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATION 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS

21 Experimental Setup: Targets: C+Pb+C Beam entranceBeam exit Diamond/Lead/Diamond cryogenic target (for high beam current) 0.2 mm Lead Foil 0.15 mm Diamond Foils BeO C Pb Bi BeO C Pb Bi Diamond g/cm 2 Lead0.194 g/cm 2 Diamond g/cm ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATION 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS TARGETS EXPERIMENT E06-007

22 4) DATA ANALYSIS 1) QUASIELASTIC (e,ep) REACTION 2) SIMULATIONS 3) DESCRIPTION OF THE EXPERIMENT 4) DATA ANALYSIS 5) RESULTS 6) SUMMARY AND CONCLUSIONS 22

23 Acquired Data Response Functions (DWIA, CC2) (Relativistic & Non-Relativistic Measured Reduced Cross Section and A TL Simulated Reduced Cross Section and A TL Luminosity Normalization Efficiency Corrections R-Function Cuts PS Criterium (PS bin > 50% PS max ) ep for reduced cross-sections Cuts in E miss Select shell MCEEP ROOT File Phase Space Simulated Yield MCEEP Data Analysis: Steps Data ROOT File Real Yield Hall A Analyzer Calibration (Beam, Optics) C++ MAC RO Spect. Factors 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALYSIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 23

24 Beam Calibration: Raster To avoid melting the 208 Pb target there exists a raster which spread the incident electrons in the whole target. The position of the beam with raster at each moment was known and it was taken into account in the event reconstruction. Beam Parameters: Energy Position: (With and Without Raster, Width) Current 24 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS

25 Beam Calibration: Current 25 The number of incident electrons should be accurately measured. A correct beam charge calibration is crucial for luminosity determination. Calibration measurements at different currents were done. 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALYSIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS

26 Target Center Q1 Q2 Dipole Q3 VDC first plane (focal plane) Particle trajectories 26 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALYSIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS Spectrometer Calibration: Optics Optimization

27 Elastic 12 C(e,e) data used for optics calibration. The common optics calibration procedure in Hall A is based on a gradient-based 2 minimization (Optimize++): The optics calibration was improved by developing a code based on a genetic algorithm for the 2 minimization. This way, all database coefficients could be optimized simultaneously and there were no problems with local minima ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALYSIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS Spectrometer Calibration: Optics Optimization

28 SIEVE SLIT NO CALIBRATED CALIBRATED The angles measured by the spectrometers are calibrated using data acquired with a sieve slit plate placed at the detectors entrance ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALYSIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS Spectrometer Calibration Optics Optimization: Angles

29 E miss (MeV) ONLINE SPECTRU M 12 C 208 P b - With the optimized database and with the appropriate raster correction, good resolution has been achieved. - Two peaks can be separated in this 208 Pb E miss spectrum (p miss =0). Ex (MeV)Shell 03s 1/ d 3/ h 11/ d 5/ g 7/2 Low lying states in 207 Tl 12 C 208 P b OPTIMIZED SPECTRUM E miss (MeV) 29 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALYSIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS Spectrometer Calibration Optics Optimization: Energy

30 30 Calibrated CT spectrum for the experiment E ( 12 C, Kin7, p miss = -300 MeV/c). Resolution 3 ns Particles with different momentum and trajectory within the spectrometers will have a different time-of-flight (TOF). This effect can be corrected and the CT is improved. A good coincidence time (CT) resolution is important to remove random coincidences, by applying a narrow cut in the CT peak. 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALYSIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS Spectrometer Calibration: Coincidence Time

31 Deadtime – Good events not recorded due to electronics or computer deadtime. Trigger efficiency – Good events not detected by the scintillators. Obtained from redundant measurements. Tracking efficiency – Good events not properly reconstructed from the VDC measurements. Obtained from the number of events reconstructed with unphysical values. Proton absorption – Protons lost during interactions with material prior to detection ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALYSIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS Efficiency corrections

32 Measured data are corrected by efficiencies, dead-time, and random coincidences. All these events are histogrammed into the relevant variables (E miss,p miss,q,, ) and cross section is obtained as: The phase-space volume of each bin is obtained with a simulation with uniform distribution over the acceptances ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS Data Analysis: Cross-Section

33 5) RESULTS 1) QUASIELASTIC (e,ep) REACTION 2) DESCRIPTION OF THE EXPERIMENT 3) SIMULATION 4) DATA ANALYSIS 5) RESULTS 6) SUMMARY AND CONCLUSIONS 33

34 12 C(e,ep) E miss 34 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS Pmiss = 0-100MeV/c

35 35 Spec. factor = ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 12 C(e,ep) – 1p 3/2 shell Reduced Cross Section

36 36 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 12 C(e,ep) - 1p 3/2 shell A TL 2 /DOF =1.59 (Rel.) 2 /DOF =2.09 (No Rel.)

37 208 Pb(e,ep) E miss 37 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS

38 38 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 208 Pb(e,ep) – Valence States Reduced Cross Section Simulations are based on DWIA (RMF) and do not include correlations

39 39 Spectroscopic Factors 3s 1/ d 3/ h 11/ d 5/ ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 208 Pb(e,ep) – Valence States Reduced Cross Section Experimental 208 Pb(e,e'p) reduced cross section (for the aggregate of valence states) together with the results from relativistic DWIA for the contributions from individual shells. Spectroscopic Factors are obtained from a (E miss, p miss ) fit.

40 40 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 208 Pb(e,ep) - Valence States A TL 2 /DOF =1.13 (Rel.) 2 /DOF =2.65 (No Rel.)

41 Spectroscopic Factors -100 < p miss < 100 MeV/c NucleusShell Spect. Factor 12 C 1p 3/ (5) 208 Pb 3s 1/ (6) 2d 3/ (6) 1h 11/ (6) 2d 5/ (6) No dependence of the spectroscopic factors with Q 2 has been found Spectroscopic Factors for several shells in 16 O measured at Q 2 =0.9 (GeV/c) 2 and in 12 C and 208 Pb measured at Q 2 =0.8 (GeV/c) ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS

42 16 O(e,ep) E miss p miss = MeV/c p 1/2 p 3/2 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 42

43 43 Spec. factor = ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 16 O(e,ep) – 1p 1/2 SHELL Reduced Cross Section

44 44 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 16 O(e,ep) – 1p 1/2 SHELL A TL A TL 2 dof =1.27 (Rel.) 2 dof =7.22 (No Rel.)

45 1) QUASIELASTIC (e,ep) REACTION 2) SIMULATIONS 3) DESCRIPTION OF THE EXPERIMENT 4) DATA ANALYSIS 5) RESULTS 6) SUMMARY AND CONCLUSIONS 45

46 Summary Two (e,ep) experiments performed at JLab with 16 O, 12 C and 208 Pb targets have been analyzed. These experiments have measured the (e,ep) reaction in perpendicular quasielastic kinematics with Q 2 ~1. In this talk, results in the p miss range [-350,350] MeV/c are shown. 208 Pb(e,ep) data have been obtained for the valence states over more complete kinematics than previous experiments, measuring the A TL asymmetry for the first time are shown. 12 C(e,ep) data was also measured. In this talk, results from the knockout of protons from the p 3/2 shell have been obtained. Results of the p 1/2 shell of 16 O have been obtained with good statistical accuracy. 209 Bi(e,ep) measured data is under analysis ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS

47 Conclusions Experimental cross sections show good agreement in general with DWIA calculations. Spectroscopic factors of 0.6 to 0.85 have been obtained in the shells analyzed in all nuclei. Carbon and Lead results show that there is no significant dependence of spectroscopic factors with Q 2 in the (GeV/c) 2 range. Simulations obtained from just relativistic mean field calculations (without long-range correlations included) seem to compare fairly well with data at both low and high missing momentum. A TL data, which are sensitive to dynamical relativistic effects, clearly favors the results that include relativistic dynamics. 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 47

48 THANKS FOR YOUR ATTENTION!

49 CROSS SECTION The (e,ep) cross section for a particular shell can be computed in general as a function of kinematical variables and the Response Functions R L,R T,R TL,R TT which contain the nuclear structure information. 1 ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALISIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS 49

50 Raster position cut – Required in 208 Pb to remove those events that hit the frame ) QUASIELASTIC (e,ep) REACTION 2 ) SIMULATIONS 3 ) DESCRIPTION OF THE EXPERIMENTS 4 ) DATA ANALYSIS 5 ) RESULTS 6 ) SUMMARY AND CONCLUSIONS Efficiency corrections


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