Radiation feedback from young star clusters embedded in \acp GMC is believed to be important to the control of star formation .
For the most massive and dense clouds , including those in which \acp SSC are born , pressure from reprocessed radiation exerted on dust grains may disperse a significant portion of the cloud mass back into the interstellar medium ( ISM ) .
Using our radiation hydrodynamics ( RHD ) code , Hyperion , we conduct a series of numerical simulations to test this idea .
Our models follow the evolution of self-gravitating , strongly turbulent clouds in which collapsing regions are replaced by radiating sink particles representing stellar clusters .
We evaluate the dependence of the star formation efficiency ( SFE ) on the size and mass of the cloud and \kappa , the opacity of the gas to infrared ( IR ) radiation .
We find that the single most important parameter determining the evolutionary outcome is \kappa , with \kappa \lower 2.15 pt \hbox { $ \buildrel > \over { \sim } $ } 15 \mbox { cm } ^ { 2 } \mbox { g } % ^ { -1 } needed to disrupt clouds .
For \kappa = 20 - 40 \mbox { cm } ^ { 2 } \mbox { g } ^ { -1 } , the resulting SFE = 50 - 70 \% is similar to empirical estimates for some super star cluster ( SSC ) -forming clouds .
The opacities required for giant molecular cloud ( GMC ) disruption likely apply only in dust-enriched environments .
We find that the subgrid model approach of boosting the direct radiation force L / c by a “ trapping factor ” equal to a cloud ’ s mean IR optical depth can overestimate the true radiation force by factors of \sim 4 - 5 .
We conclude that feedback from reprocessed IR radiation alone is unlikely to significantly reduce star formation within \acp GMC unless their dust abundances or cluster light-to-mass ratios are enhanced .