2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/139103We investigate the asymptotic tail behavior of massive scalar fields in Schwarzschild background. It is shown that the oscillatory tail of the scalar field has the decay rate of $t^{-5/6}$ at asymptotically late times, and the oscillation with the period $2π/m$ for the field mass $m$ is modulated by the long-term phase shift. These behaviors are qualitatively similar to those found in nearly extreme Reissner-Nordström background, which are discussed in terms of a resonant backscattering due to the space-time curvature.21 pages, 2 figures, accepted for publication in Phys.Rev.DGeneral Relativity and Quantum Cosmologytext