  Microscopic theory of the nuclear response based on the relativistic
meson-nucleon Lagrangian is applied to the description of the isoscalar giant
monopole resonance (ISGMR) in a variety of nuclear systems. It is shown that
the parameter-free inclusion of beyond-mean-field correlations of the
quasiparticle-vibration coupling (qPVC) type in the leading approximation
allows for a simultaneous realistic description of the ISGMR in nuclei of lead,
tin, zirconium, and nickel mass regions, which is difficult on the mean-field
level. The calculations employ the finite-range effective meson-nucleon
interaction, which, in combination with the qPVC, has consistently demonstrated
the ability to reliably describe many other nuclear structure phenomena.
Systematic calculations of the isoscalar monopole response for nickel isotopes
help reveal the central role of the coupling between the ISGMR and the
low-energy quadrupole states in the placement of the ISGMR centroids.
