lifetime broadening

https://doi.org/10.1351/goldbook.08632
Homogeneous line-broadening due to the limited lifetime of energy states involved in a transition.
Note:
The lifetime may be limited by the natural lifetime, by collisions, as in pressure broadening, or by anharmonic vibrational interactions as in phonon-phonon collisions in solids.
Source:
PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 753 (https://doi.org/10.1515/pac-2019-0203)