Saito, K.Kouno, H.Tsushima, K.Thomas, A.2010-04-302010-04-302005European Physical Journal A: Hadrons and Nuclei, 2005; 26(2):159-1651434-60011434-601Xhttp://hdl.handle.net/2440/58000We generalize the linear σ model in order to develop a chiral-invariant model of the nuclear structure. The model is natural, and contains not only the usual σ-meson which is the chiral partner of the pion but also a new chiral singlet that is responsible for the medium-range nucleon-nucleon attraction. This approach provides significant advantages in terms of its description of nuclear matter and finite nuclei in comparison with conventional models based on the linear σ model.en© Societa Italiana di Fisica / Springer-Verlag 2005Journal article002009618910.1140/epja/i2005-10170-70002341169000022-s2.0-2914449811335239Thomas, A. [0000-0003-0026-499X]