Fast LiH destruction in reaction with H: quantum calculations and astrophysical consequences - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




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Abstract: We present a quantum-mechanical study of the exothermic 7LiH reaction with H.Accurate reactive probabilities and rate coefficients are obtained by solvingthe Schrodinger equation for the motion of the three nuclei on a singleBorn-Oppenheimer potential energy surface PES and using a coupled-channelhyperspherical coordinate method. Our new rates indeed confirm earlier,qualitative predictions and some previous theoretical calculations, asdiscussed in the main text. In the astrophysical domain we find that thedepletion process largely dominates for redshift z between 400 and 100, arange significant for early Universe models. This new result fromfirst-principle calculations leads us to definitively surmise that LiH shouldbe already destroyed when the survival processes become important. Because ofthis very rapid depletion reaction, the fractional abundance of LiH is found tobe drastically reduced, so that it should be very difficult to manage toobserve it as an imprinted species in the cosmic background radiation CBR.The present findings appear to settle the question of LiH observability in theearly Universe. We further report several state-to-state computed reactionrates in the same range of temperatures of interest for the present problem.



Author: S. Bovino, M. Wernli, F. A. Gianturco

Source: https://arxiv.org/







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