Search for Quadrupole Strength in the Electro-excitation of the Delta(1232)

C. Mertz; C. Vellidis; R. Alarcon; D. H. Barkhuff; A. M. Bernstein; W. Bertozzi; V. Burkert; J. Chen; J. R. Comfort; G. Dodson; S. Dolfini; K. Dow; M. Farkhondeh; J. M. Finn; S. Gilad; R. W. Gothe; X. Jiang; K. Joo; N. I. Kaloskamis; A. Karabarbounis; J. J. Kelly; S. Kowalski; C. Kunz; R. W. Lourie; J. I. McIntyre; B. D. Milbrath; R. Miskimen; J. H. Mitchell; C. N. Papanicolas; C. F. Perdrisat; A. J. Sarty; J. Shaw; S. -B. Soong; D. Tieger; C. Tschalaer; W. Turchinetz; P. E. Ulmer; S. Van Verst; G. A. Warren; L. B. Weinstein; S. Williamson; R. J. Woo; A. Young

doi:10.1103/physrevlett.86.2963

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arXiv · nucl-ex/9902012

Search for Quadrupole Strength in the Electro-excitation of the Delta(1232)

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Abstract

High-precision H(e,e'p)pi0 measurements at Q2=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 amplitude ratios, Rsm=(-6.5 +- 0.2{stat+sys} +- 2.5{mod}) % and Rem=(-2.1 +- 0.2{stat+sys} +- 2.0{mod}) %, are dominated by model error. Previous Rsm and Rem results should be reconsidered after the model uncertainties associated with the method of their extraction are taken into account.

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C. Mertz, C. Vellidis, R. Alarcon, D. H. Barkhuff, A. M. Bernstein, W. Bertozzi, V. Burkert, J. Chen, J. R. Comfort, G. Dodson, S. Dolfini, K. Dow, M. Farkhondeh, J. M. Finn, S. Gilad, R. W. Gothe, X. Jiang, K. Joo, N. I. Kaloskamis, A. Karabarbounis, J. J. Kelly, S. Kowalski, C. Kunz, R. W. Lourie, J. I. McIntyre, B. D. Milbrath, R. Miskimen, J. H. Mitchell, C. N. Papanicolas, C. F. Perdrisat, A. J. Sarty, J. Shaw, S. -B. Soong, D. Tieger, C. Tschalaer, W. Turchinetz, P. E. Ulmer, S. Van Verst, G. A. Warren, L. B. Weinstein, S. Williamson, R. J. Woo, A. Young. 2000-12-06. Search for Quadrupole Strength in the Electro-excitation of the Delta(1232). https://doi.org/10.1103/physrevlett.86.2963

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