Eur. Phys. J. A (2004) 20: 429-433
https://doi.org/10.1140/epja/i2003-10167-2

The Gamow-Teller resonance in finite nuclei in the relativistic random phase approximation

¹ China Institute of Atomic Energy, 102413, Beijing, PRC
² Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator of Lanzhou, 730000, Lanzhou, PRC
³ Institut de Physique Nucléaire, IN2P3-CNRS, F-91406, Orsay Cedex, France
⁴ Department of Applied Physics, Fukui University, 910-8507, Fukui, Japan
⁵ RIKEN, 2-1 Hirosawa, 351-0198, Wako-shi, Saitama, Japan

^* e-mail: mazy12@iris.ciae.ac.cn

Abstract

Gamow-Teller (GT) resonances in finite nuclei are studied in a fully consistent relativistic random phase approximation (RPA) framework. A relativistic form of the Landau-Migdal contact interaction in the spin-isospin channel is adopted, which has a vector part as well as a time-like component. This choice ensures that the GT excitation energy in nuclear matter is correctly reproduced in the non-relativistic limit. The GT response functions of doubly magic nuclei ⁴⁸Ca, ⁹⁰Zr and ²⁰⁸Pb are calculated using the parameter set NL3 and g’ = 0.6. It is found that the effects related to Dirac sea states account for a reduction of 6-7% in the GT sum rule. The quenching of the GT strength in finite nuclei implies that the value of g’ in the relativistic model might be enlarged about 7%. The time component in the relativistic form of the Landau-Migdal force plays a little role in GT resonance energies.