Observation of perturbations in the rotational manifold of the CN B2Σ+v= 1 level caused by interaction with the CN A 2Πiv= 12 level
Abstract
The (1, 0) band of the CN B2Σ+–X2Σ+ transition has been examined using sub-Doppler laser-induced fluorescence (LIF), and the spin–rotation splitting of the upper state was found to vary irregularly. This behaviour is identified as arising from localised perturbations of the CN B2Σ+(v= 1) level caused by interaction with levels of the same total angular momentum arising from the v= 12 vibrational level of the A2Πi state. A deperturbation analysis based on diagonalising the Hamiltonian of the B2Σ+ and A2Πi states including their mutual interaction is able to match well the experimentally observed separations between the F1(J=N+½) and F2(J=N–½) levels of the B2Σ+ state.