  We discuss, in the context of precision measurement of Delta m^2_{31} and
theta_{13}, physics capabilities enabled by the recoilless resonant absorption
of monochromatic antineutrino beam enhanced by the M\"ossbauer effect recently
proposed by Raghavan. Under the assumption of small relative systematic error
of a few tenth of percent level between measurement at different detector
locations, we give analytical and numerical estimates of the sensitivities to
Delta m^2_{31} and sin^2 2theta_{13}. The accuracies of determination of them
are enormous; The fractional uncertainty in Delta m^2_{31} achievable by 10
point measurement is 0.6% (2.4%) for sin^2 2theta_{13} = 0.05, and the
uncertainty of sin^2 2theta_{13} is 0.002 (0.008) both at 1 sigma CL with the
optimistic (pessimistic) assumption of systematic error of 0.2% (1%). The
former opens a new possibility of determining the neutrino mass hierarchy by
comparing the measured value of Delta m^2_{31} with the one by accelerator
experiments, while the latter will help resolving the theta_{23} octant
degeneracy.
