Distribution function, reaction rates and spectral line profile

Quantum mechanics predicts the existence of power law “tails” in the distribution function over momentum in dense media even at the condition of thermodynamics equilibrium. Generalized expressions for the threshold process reaction rates show that reaction rates with released energy (e.g. vibrational-translational relaxation, chemical reaction, fusion rates) may be substantially increased due to quantum corrections. Spectral line profile also may have corrections at large detunings from line centre due to modification of distribution function. Cases of emission and absorption of radiation are analysed.