Second random phase approximation and renormalized realistic interactions

• Published in: Physics letters. B Vol. 671; no. 3; pp. 356 - 360
• Main Authors: Papakonstantinou, P., Roth, R.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 26-01-2009; Elsevier
• Subjects: Exact sciences and technology; Giant resonances; Nuclear physics; Physics; Realistic effective interactions; Second RPA; The physics of elementary particles and fields; Unitary correlation operator method; 21.30.Fe; Unitary correlation operator method; Realistic effective interactions; Second RPA; 21.60.-n; Giant resonances; 24.30.Cz; 21.60.Jz; Operator; Dipoles; Ground states; Self consistency; Random phase approximation; Correlation methods; Quadrupoles; Two body system; First order; Isovectors; Nucleons; Effective mass
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2008.12.037

We examine the response of closed-shell nuclei using a renormalized interaction, derived with the Unitary Correlation Operator Method (UCOM) from the Argonne V18 potential, and a second RPA (SRPA) method. The same two-body interaction is used to derive the Hartree–Fock ground state and the SRPA equations. Our results show that the coupling of particle–hole states to higher-order configurations produces sizable effects compared with first-order RPA. A much improved description of the isovector dipole and isoscalar quadrupole resonances is obtained, thanks in part to the more fundamental treatment of the nucleon effective mass offered by SRPA. The present work suggests the prospect of describing giant resonance properties realistically and consistently within SRPA or other extended RPA theories. Self-consistency issues of the present SRPA method and residual three-body effects are pointed out.