  The three-body force (TBF) effect on the neutrino emissivity in neutron star
matter and the total neutrino emissivity of neutron stars have been
investigated within the framework of the Brueckner-Hartree-Fock approach by
adopting the AV18 two-body interaction plus a microscopic TBF. The neutrino
emissivity from the direct Urca process turns out to be much larger than that
from the modified Urca process. Inclusion of the TBF reduces strongly the
density thresholds of the direct Urca processes involving electrons and muons.
The TBF effect on the total neutrino emissivity of neutron stars is shown to be
negligibly weak for neutron stars with small masses. For neutron stars with
large masses, the TBF effect becomes visible and inclusion of the TBF may
enhance the total neutrino emissivity by about 50% for neutron stars with a
given mass of $M=1.6M_{\odot}$.
