Journal article

Publication year: 1997

Pages: 391-426

Journal: Nuclear Physics A: Nuclear and Hadronic Physics

Volume number: 627

Issue number: 3

ISSN: 0375-9474

eISSN: 1873-1554

Open access status: Green

DOI Link: https://doi.org/10.1016/S0375-9474(97)00029-8

Publisher: Elsevier

Abstract: 
In this paper we develop a theoretical framework which allows us to study excitations of the nucleon. Assuming an effective two-body interaction as a model for low-energy QCD, we derive a relativistic TDHF equation for a many-body system of quarks. To render the Dirac-sea contribution to the mean field finite, we introduce a symmetry-conserving regularization scheme, In the small-amplitude limit we derive an RPA equation. The structure of the ph interaction and modifications due to the regularization scheme are discussed. We give a prescription to obtain a nucleon state with good angular momentum (J) and isospin (T) quantum numbers on mean-field level. To study excitations, we develop a tensor-RPA approach, which is an extension of the conventional RPA techniques to systems with a nonscalar ground state. This allows us to construct excited states with good (J/T) quantum numbers. We discuss a method to reduce the overcomplete ph-space and compute the tensor-RPA interaction matrix elements. Finally we extend our scheme to include (3/2(divided by), 3/2)-states. (C) 1997 Elsevier Science B.V.

Harvard Citation style: Hardt, S., Geiss, J., Lenske, H. and Mosel, U. (1997) RPA approach to the excitations of the nucleon part I: Theory, Nuclear Physics A: Nuclear and Hadronic Physics, 627(3), pp. 391-426. https://doi.org/10.1016/S0375-9474(97)00029-8

APA Citation style: Hardt, S., Geiss, J., Lenske, H., & Mosel, U. (1997). RPA approach to the excitations of the nucleon part I: Theory. Nuclear Physics A: Nuclear and Hadronic Physics. 627(3), 391-426. https://doi.org/10.1016/S0375-9474(97)00029-8