Search for quadrupole strength in the electroexcitation of the Δ+(1232)

被引:136
作者
Mertz, C [1 ]
Vellidis, CE
Alarcon, R
Barkhuff, DH
Bernstein, AM
Bertozzi, W
Burkert, V
Chen, J
Comfort, JR
Dodson, G
Dolfini, S
Dow, K
Farkhondeh, M
Finn, JM
Gilad, S
Gothe, RW
Jiang, X
Joo, K
Kaloskamis, NI
Karabarbounis, A
Kelly, JJ
Kowalski, S
Kunz, C
Lourie, RW
McIntyre, JI
Milbrath, BD
Miskimen, R
Mitchell, JH
Papanicolas, CN
Perdrisat, CF
Sarty, AJ
Shaw, J
Soong, SB
Tieger, D
Tschalær, C
Turchinetz, W
Ulmer, PE
Van Verst, S
Warren, GA
Weinstein, LB
Williamson, S
Woo, RJ
Young, A
机构
[1] Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA
[2] Univ Athens, Inst Accelerating Syst & Applicat, Athens, Greece
[3] Univ Athens, Dept Phys, Athens, Greece
[4] Univ Virginia, Inst Nucl & Particle Phys, Charlottesville, VA 22901 USA
[5] Univ Virginia, Dept Phys, Charlottesville, VA 22901 USA
[6] MIT, Nucl Sci Lab, Dept Phys, Cambridge, MA 02139 USA
[7] MIT, Bates Accelerator Ctr, Cambridge, MA 02139 USA
[8] Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA
[9] Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA
[10] Univ Bonn, Dept Phys, D-5300 Bonn, Germany
[11] Univ Massachusetts, Dept Phys, Amherst, MA 01003 USA
[12] Univ Maryland, Dept Phys, College Pk, MD 20742 USA
[13] Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA
[14] Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA
[15] Univ Illinois, Dept Phys, Urbana, IL 61801 USA
关键词
D O I
10.1103/PhysRevLett.86.2963
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
High-precision H-1(e,e 'p)pi (0) measurements at Q(2) = 0.126 (GeV/c)(2) are reported, which allow the determination of quadrupole amplitudes in the gamma *N --> Delta transition; they simultaneously test the reliability of electroproduction models. The derived quadrupole-to-dipole (I = 3/2) amplitude ratios, R-SM = (-6.5 +/- 0.2(stat+sys) +/- 2.5(mod))% and R-EM = (-2.1 +/- 0.2(stat+sys) +/- 2.0(mod))%, are dominated by model error. Previous R-SM and R-EM results should be reconsidered after the model uncertainties associated with the method of their extraction are taken into account.
引用
收藏
页码:2963 / 2966
页数:4
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