Knowledge Bank

The variation with the rotational quantum number N of the widths of lines in the $(0,90,0)-(0,01,0)$ band of the $HCOA~2A""-X~2A\prime$ transition is recorded using a single-mode dye Laser. The HCO radical is produced in a radio frequency discharge is acetaldehyde $(CH3CHO)$ and Ar/He, and the $A~-X~$ transition in the 570-620 nm region is detected by laser-induced changes in the discharge impedance. The variation of the observed line widths with N is interpreted in terms of Coriolis interaction and K-type resonance of the $(0,90,0)\Sigma (K\prime =0)$ level with nearby strongly predissociated $\Pi (K\prime =1)$ and $\Delta (K\prime =2)$ levels, respectively, of the upper state.