Abstract:
Rotational quenching cross sections are computed for ultracold rotational transitions of NCCN induced by collision with 3,4He. Rotational quenching of He-NCCN involving two isotopes resulted in higher cross sections for
lighter isotope. Quenching cross-section in ultracold regime is found to obey Wigner’s threshold law. Rate
coefficients are obtained from 10−5 to 50 K. To further analyse the isotopic effect of He, scattering lengths are
computed. The imaginary part of scattering length is very large for 3
He-NCCN. Rate coefficient in the limit of
zero temperature is found to be an order of magnitude larger for 3
He-NCCN.
