2018 Impact factor 2.481
Hadrons and Nuclei
Eur. Phys. J. A 2, 403-409

A relativistic study of the nucleon helicity amplitudes

M. De Sanctis1 - E. Santopinto2 - M.M. Giannini2

1 INFN, Sezione di Roma, P.le A.Moro 2, I-00185 Roma, Italy
2 Dipartimento di Fisica dell'Università di Genova, I.N.F.N., Sezione di Genova, via Dodecaneso 33, 16164 Genova, Italy (e-mail:giannini@genova.infn.it)

Received: 16 April 1998 Communicated by V.V. Anisovich

Abstract
We perform a calculation of the relativistic transition form factors for the electromagnetic excitation of the nucleon resonances. We use as input the 3-quark wave functions obtained in a Constituent Quark Model with three-body forces in the hypercentral approach. With respect to the non relativistic calculations a significant contribution is obtained up to $Q^2 \simeq 2 (GeV/c)^2$. However, the low Q2-behaviour exhibits a lack of strength, which may be connected with the need of taking into account explicitly further degrees of freedom beyond the three constituent quark ones.

PACS
12.39.Ki Relativistic quark model - 13.40.Gp Electromagnetic form factors - 14.20.Gk Baryon resonances with S = 0


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