1. EINN 2005 BLAST: A Detector for Internal Target Experiments  Introduction ¶ Overview ¶ Present Results ¶ Outlook John Calarco, EINN 2005 “We had a BLAST at MIT-Bates”

2. EINN 2005 Approved BLAST Scientific Program Form Factor Measurements: Q 2  1.0 (GeV/c) 2 Proton Charge and Magnetism Elastic Scattering with Polarized Beam and H Target (01-01) Neutron Charge and Magnetism and Deuteron Electromagnetic Structure Quasi-elastic Scattering with Polarized Beam and D Target (89-12 and 91-09) Elastic scattering off Tensor and Vector Polarized Deuterium (00-03 and 03-02)

3. EINN 2005 General Kinematics for Polarized e Scattering on a Polarized Target

4. EINN 2005 Bates Linac  500MeV Linac recirculated to reach up to 1GeV  Inject into South Hall Ring  Polarization maintained by Siberian snake  Polarization monitored real time by Compton Polarimeter  Internal Target located in the ring vacuum

5. EINN 2005 Left-right symmetric detector –simultaneous parallel and perpendicular asymmetry determination Large acceptance –covers 0.1GeV 2 ≤ Q 2 ≤ 1GeV 2 –out-of-plane measurements DRIFT CHAMBERS –momentum determination, particle identification CERENKOV COUNTERS –electron/pion discrimination SCINTILLATORS –TOF, particle identification NEUTRON COUNTERS –neutron determination MAGNETIC COILS –3.8kG toroidal field The BLAST Spectrometer DRIFT CHAMBERS CERENKOV COUNTERS SCINTILLATORS NEUTRON COUNTERS TARGET BEAM

6. EINN 2005 BLAST: Configuration used for present data

7. EINN 2005

8. ep Elastic Kinematic Correlation

9. EINN 2005  G E /G M Results

10. EINN 2005 Motivation: Why T 20 e-d elastic scattering: G C G M G Q G Q > D-state > Tensor Force Rosenbluth Separation 3 rd Measurement to separate 3 form factors Tensor Asymmetry in e-d elastic scattering

11. EINN 2005  Kinematics:  p e =24MeV   d =1 o …  Mass: timing & tracking Blue: everything Red: after coplanarity cut Deuterons Protons  + ? e-d Elastic Event Selection e - left, d + right e - right, d + left

12. EINN 2005 T 20 and T 21 for ed elastic scattering

13. EINN 2005 Difference between T 20 and theory

14. EINN 2005 Helicity dependent T 10 and T 11 from ed elastic scattering

15. EINN 2005 G M from world A(Q 2 ) and BLAST T 20, T 21, and helicity dependent T 11

16. EINN 2005 Beam-Vector Asymmetry for D(e,e’p) QES

17. EINN 2005 Beam-Vector Asymmetry (cont.)

18. EINN 2005 Tensor Asymmetry Results

19. EINN 2005 Potential Dependence Monte Carlo for Bonn, Paris, and V18 potentials compared to BLAST data Potential dependence small compared to MEC and IC contributions

20. EINN 2005 G E n from A v ed in polarized D(e,e’n)

21. EINN 2005 Conclusions and Outlook World-class data for G p E /G p M, G n E, D(e,e’) elastic T 20, T 21, and helicity dependent T 11, D(e,e’p) QES A V ed and A T d,, Inclusive H(e,e’)X and D(e,e’)X Analysis still in progress Many other channels to be analyzed: H(e,e’p)    H(e,e’n)  , H(  n  + ), etc.. Will BLAST run again at another facility?

22. EINN 2005 BLAST COLLABORATION R. Alarcon, E. Geis, J. Prince, B. Tonguc, A. Young Arizona State University, Tempe, AZ 85287 J. Althouse, C. D ’ Andrea, A. Goodhue, J. Pavel, T. Smith, Dartmouth College, Dartmouth, NH D. Dutta, H. Gao, W. Xu Duke University Durham, NC 27708-0305 H. Arenh ö vel, Johannes Gutenberg-Universit ä t, Mainz, Germany T. Akdogan, W. Bertozzi, T. Botto, M. Chtangeev, B. Clasie, C. Crawford, A. Degrush, K. Dow, M. Farkhondeh, W. Franklin, S. Gilad, D. Hasell, E. Ilhoff, J. Kelsey, M. Kohl, H. Kolster, A. Maschinot, J. Matthews, N. Meitanis, R. Milner, R. Redwine, J. Seely, S. Sobczynski, C. Tschalaer, E. Tsentalovich, W. Turchinetz, Y. Xiao, C. Zhang, V. Ziskin, T. Zwart Massachusetts Institute of Technology, Cambridge, MA 02139 and Bates Linear Accelerator Center, Middleton, MA 01949 J. Calarco, W. Hersman, M. Holtrop, O. Filoti, P. Karpius, A. Sindile, T. Lee University of New Hampshire, Durham, NH 03824 J. Rapaport Ohio University, Athens, OH 45701 K. McIlhany, A. Mosser United States Naval Academy, Annapolis, MD 21402 J. F. J. van den Brand, H. J. Bulten, H. R. Poolman Vrije Universitaet and NIKHEF, Amsterdam, The Netherlands W. Haeberli, T. Wise University of Wisconsin, Madison, WI 53706

23. EINN 2005 The BLASTers

24. EINN 2005 GnMGnM

25. Asymmetries A L and A R

26. EINN 2005  G E /G M from ep Elastic

27. EINN 2005 Tensor Asymmetry (cont.)

28. EINN 2005  G E /G M — World Data

29. EINN 2005 G E and G M Results BLAST + World Data

30. EINN 2005 Detector Performance All detectors operated at or near designed level –Drift chambers ~98% efficient per wire –TOF resolution of 300ps Clean event selection –Cerenkov counters 85% efficient in electron/pion discrimination –Neutron counters 10% (25-30%) efficient in left (right) sectors Reconstruction resolutions good but still being improved currentgoal pp 3%2%  0.5°0.3°  0.5°0.5º zz 1cm

31. EINN 2005 T 20 for ed elastic scattering

32. EINN 2005 G n E from D(e,e’n)