GEn will run in Hall A from about Feb 28, 2005, to May 09, 2005. Please consider signing up for shifts.
Knowledge of the neutron electric form factor GEn is essential for the understanding of the structure of the nucleon, and a key ingredient in the analysis of processes involving electromagnetic interactions with complex nuclei. Recent results on the electric form factor of the proton GEp from experiments E93-027 and E99-007 utilizing the recoil polarization technique at JLab, show that the ratio GEp/GMp decreases sharply as Q2 increases. Thus, the electric and magnetic form factors behave in a different manner from values of Q2 of the order of 1 (GeV/c)2 upwards. The same mechanisms that cause such a deviation should also be present in the neutron, but no accurate data exists at these momentum transfers.
In the GEn 02-013 experiment at JLab's Hall A we intend to measure the neutron electric form factor GEn at high four-momentum transfer values of Q2 = 1.3, 2.4, and 3.4 (GeV/c)2 in double polarized 3He(e, e'n) scattering in quasi-elastic kinematics, by measuring the asymmetry AT of the cross section. The experiment will make use of the polarized 3He target and of the polarized CEBAF beam at moderate beam energies of 1.644, 2.444, and 3.244 GeV. The electrons will be recorded in the BigBite spectrometer whereas the neutrons will be detected in an array of scintillators. Because of the high kinetic energy of the neutrons it is possible to achive a high neutron detection efficiency with an excellent background suppression. During the scheduled beamtime of 768 hours the GEn value can be measured to a statistical accuracy of ΔGEn/GEn= 0.14 for the three proposed values of Q2.
⇒ The Spokespeople:
♣ Bogdan Wojtsekhowski (Contact Person)
⇒ Thesis Students (except the last one in the list):
♥ Sergey Abrahamyan (
♥ Brandon Craver (
♥ Aidan Kelleher (The
♥ Ameya Kolarkar (
♥ Jonathan Miller (
♥ Seamus Riordan (Carnegie Mellon University, Pa, USA)
Singh (Non-thesis student,
⇒ Others in the Collaboration (includes shift-takers; I'll put in the affiliations soon ...):
J.P. Chen, E.
Chudakov, C. deJager, P. Degtiarenko, R.J. Feuerbach, J. Gomez, O. Hansen, D. W. Higinbotham,
M. Jones, J. LeRose, W. Melnitchouk, R. Michaels, S. Nanda, B. Reitz, A. Saha,
B. Wojtsekhowski, S. Wood
Thomas Jefferson National Accelerator Facility, Newport News, VA 23606
B. Anderson, A. T. Katramotou, K. McCormick, G. G. Petratos, J. Watson,
Kent State University, Kent, OH 44242
G. Cates, D. Day, A. Deur, R. Lindgren, N. Liyanage, V. Nelyubin†, B. E. Norum, O. Rondon, S. Tajima, K. Wang
University of Virginia, Charlottesville, VA 22901
D. Nikolenko, I. Rachek
J. Annand, D. Ireland, J. Kellie, K. Livingston, G. Rosner, D. Watts
University of Glasgow, Glasgow, Scotland
P. Markowitz, M. M. Sargsian, L.
A. Danagoulian, A. Nathan
K. Allada, C. Dutta, W. Korsh, P. Zolnierczuk
University of Kentucky, Lexington, KY 40506
J. M. Udias
Universidad Complutense de
J. Calarco, W.
R. Niyazov, A. Radyushkin, L.
Rensselaer Polytechnic Institute,
R. Gilman, C. Glashausser, X. Jiang, G. Kumbartzki, R. Ransome
Rutgers, The State University of New Jersey, Piscataway, NJ 08854
J. M. Laget, F. Sabatie
F. Garibaldi, M. Iodice
INFN, Rome, Italy
R. De Leo
INFN, Bari, Italy
J. Lichtenstadt, E. Piasetzky
Tel Aviv University, Israel
S. Choi, A. Lukhanin, Z.-E.
Meziani, N. Ploquin, B. Sawatzky, K. Slifer, P. Solvignon
Temple University, Philadelphia, PA 19122
D. Armstrong, T. Averett, M. Finn, C. Perdrisat, B. Moffit, V. Sulkoski, J.
Katich, S. Fuchs, K. Grimm
College of Willaim and Mary, Williamsburg, VA 23185
K. Egiyan, A. Ketikyan, A. Shahinyan, H. Voskanyan
Yerevan Physics Institute,
D. Margaziotis, T. Ngo
California State University, Los Angeles, CA
Arie Beck, Sharon Beck
The Hall A Collaboration
leave from SPNPI of Russian Academy of Sciences,
⇒ Helpers in Hardware:
Coming soon ...
Last modified: Wed Feb 8 19:34:56 EST 2006