Properties of liquid argon scintillation light emission

Liquid argon is used as active medium in a variety of neutrino and dark matter experiments thanks to its excellent properties charge yield transport scintillator. scintillation photons are emitted narrow band 10 nm centered around 127 with characteristic time profile made by two components originated the decay lowest lying singlet, ${^{1}\mathrm{\ensuremath{\Sigma}}}_{u}^{+}$, triplet states, ${^{3}\mathrm{\ensuremath{\Sigma}}}_{u}^{+}$, excimer ${\mathrm{Ar}}_{2}^{*}$ dissociative ground state. A model proposed which takes into account quenching long lived states through self-interaction other or interaction molecular ${\mathrm{Ar}}_{2}^{+}$ ions. The predicts signals dependence on intensity an external electric field density deposited energy, if relative abundance unquenched fast slow know. successfully explains experimentally observed component applied increase photon liquid when doped small quantities xenon (at part per million level). also pulse shape parameter, ${F}_{\text{prompt}}$, for electron nuclear recoils recoil energy behavior light argon, ${\mathcal{L}}_{\mathrm{eff}}$.