Resonant particle production with nonminimally coupled scalar fields in preheating after inflation

We investigate the resonant particle production of a scalar field (Formula presented) coupled nonminimally to a spacetime curvature (Formula presented) (Formula presented) as well as to an inflaton field φ (Formula presented) In the case of (Formula presented) the ξ effect assists g resonance in certain parameter regimes. However, for (Formula presented) (Formula presented) resonance is not enhanced by the (Formula presented) effect because of the (Formula presented) suppression effect as well as a back reaction effect. If (Formula presented) the maximal fluctuation of produced (Formula presented) particles is (Formula presented) for (Formula presented) which is larger than the minimally coupled case with (Formula presented)