Kozyryev, I.Baum, LouisMatsuda, KyleOlson, PeterHemmerling, BoergeDoyle, John2016-08-242015Kozyryev, Ivan, Louis Baum, Kyle Matsuda, Peter Olson, Boerge Hemmerling, and John M Doyle. 2015. “Collisional Relaxation of Vibrational States of SrOH with He at 2 K.” New J. Phys. 17 (4) (April 2): 045003. doi:10.1088/1367-2630/17/4/045003.1367-2630http://nrs.harvard.edu/urn-3:HUL.InstRepos:27885359Vibrational relaxation of strontium monohydroxide (SrOH) molecules in collisions with helium (He) at 2 K is studied.We find the diffusion cross section of SrOH at 2.2 K to be σ =±× − d (5 2) 10 cm 14 2 and the vibrational quenching cross sectionfor the (100) Sr–O stretching mode to be σq =±× − (7 2) 10 cm 17 2. The resulting ratio γ 100 = ∼ σ σ d q 700 is more than an order of magnitude smaller thanfor previously studiedfew-atom radicals (Au et al 2014 Phys. Rev.A90 032703 ).We also determine the Franck–Condonfactorfor SrOH ( Π Σ ← + A˜ (100) X˜ (000) 2 1 2 2 ) to be ± × − (4.8 0.8) 10 2.en-USJournal Article2016-08-2410.1088/1367-2630/17/4/045003