  A phase of strong interacting matter with deconfined quarks is expected in
the core of massive neutron stars. In this article, we perform a study of the
hadron-quark phase transition in cold (T = 0) neutron star matter and we
calculate various structural properties of hybrid stars. For the quark phase,
we make use of an equation of state (EOS) derived with the field correlator
method (FCM) recently extended to the case of nonzero baryon density. For the
hadronic phase, we consider both pure nucleonic and hyperonic matter, and we
derive the corresponding EOS within a relativistic mean field approach. We make
use of measured neutron star masses, and particularly the mass $M = 1.97 \pm
0.04 \, M_\odot$ of PSR J1614 -2230 to constrain the values of the gluon
condensate $G_2$, which is one of the EOS parameters within the FCM. We find
that the values of $G_2$ extracted from the mass measurement of PSR J1614 -2230
are consistent with the values of the same quantity derived within the FCM from
recent lattice QCD calculations of the deconfinement transition temperature at
zero baryon chemical potential. The FCM thus provides a powerful tool to link
numerical calculations of QCD on a space-time lattice with measured neutron
star masses.
