  We present a comprehensive analysis of photon emission and atomic collision
processes in two-phase argon doped with xenon and nitrogen. The dopants are
aimed to convert the VUV emission of pure Ar to the UV emission of the Xe
dopant in the liquid phase and to the near UV emission of the N2 dopant in the
gas phase. Such a mixture is relevant to two-phase dark matter and low energy
neutrino detectors, with enhanced photon collection efficiency for primary and
secondary scintillation signals. Based on this analysis, we show that the
recently proposed hypothesis of the enhancement of the excitation transfer from
Ar to N2 species in the two-phase mode is either incorrect or needs assumption
about a new extreme mechanism of excitation transfer coming into force at lower
temperatures, in particular that of the resonant excitation transfer via ArN2
compound (van der Waals molecule).
