The equation of state for neutron matter is calculated within relativistic Hartree-Fock approximation .
The tensor couplings of vector mesons to baryons are included , and the change of baryon internal structure in matter is also considered using the quark-meson coupling model .
We obtain the maximum neutron-star mass of \sim 2.0 M _ { \odot } , which is consistent with the recently observed , precise mass , 1.97 \pm 0.04 M _ { \odot } .
The Fock contribution is very important and , in particular , the inclusion of tensor coupling is vital to obtain such large mass .
The baryon structure variation in matter also enhances the mass of a neutron star .