VIOLATION OF NUCLEAR-SPIN SYMMETRY IN COLLISIONS OF SYMMETRICAL TOPS

Citation
B. Nagels et al., VIOLATION OF NUCLEAR-SPIN SYMMETRY IN COLLISIONS OF SYMMETRICAL TOPS, Chemical physics letters, 294(4-5), 1998, pp. 387-390
Citations number
19
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics, Atomic, Molecular & Chemical
Journal title
ISSN journal
0009-2614
Volume
294
Issue
4-5
Year of publication
1998
Pages
387 - 390
Database
ISI
SICI code
0009-2614(1998)294:4-5<387:VONSIC>2.0.ZU;2-B
Abstract
Evidence of nuclear-spin symmetry violation in molecular collisions is presented. Measurements of the ortho-para conversion rates in (CH3F)- C-12 embedded in an gaseous oxygen or nitrogen shows that oxygen speed s up the nuclear spin conversion by 2 x 10(-4) s(-1)/Torr contrary to nitrogen which slows down the conversion by 1 x 10(-4) s(-1)/Torr. The difference is attributed to direct collisional transitions between th e ortho and para states in CH3F due to the large oxygen magnetic momen t, which is much smaller in the case of nitrogen. (C) 1998 Published b y Elsevier Science B.V. All rights reserved.