We know the intensity distribution from a black-body at a fixed temperature using Planck's equation. During evaluating density of states we use a factor of 2 (for two polarization states: under-graduate text level explanation). Now suppose we have a hypothetical black-body emitting massive bosons (W+, W-, Z0, etc.) then what will be the factor? Whether it will remain same or change? If it is changed than what will happen to the intensity distribution shape?