Chirally symmetric effective field theory for nuclei

The Lorentz-invariant nuclear lagrangian of Furnstahl, Serot and Tang (FST) is discussed. The FST lagrangian is derived in terms of an effective field theory and exhibits a nonlinear realization of chiral symmetry $SU(2)_L\times SU(2)_R$. The relevant degrees of freedom are nucleons, pions and the low-lying non-Goldstone bosons: isoscalar scalar ($\sigma$) and vector ($\omega$) mesons, and isovector vector ($\rho$) mesons. The terms in the lagrangian are organized by applying Georgi's naive dimensional analysis and naturalness condition. As a consequence all coupling constants in theory are dimensionless and of order unity.