Lifetime Broadening of Excited Pyrazine Adsorbed on Ag(111)

Abstract
High-resolution electron-energy-loss spectroscopy has been used to study the vibrational broadening in the $^{1}B_{2\mathrm{u}}(\ensuremath{\pi},{\ensuremath{\pi}}^{*})$ excited state of pyrazine adsorbed on Ag(111). Strong lifetime broadening of ~100 mV for the first and ~20 mV for the second pyrazine layers are determined. These lifetimes are in reasonable agreement with those predicted by classical theory.