translate English to French: The radio-frequency and microwave spectrum of SiH4 corresponding to ΔJ = 0 ‘forbidden’ rotational transitions between the centrifugal distortion multiplets of levels has been studied by using the method of infrared–microwave double resonance in a laser cavity.
On a étudié le spectre de radiofréquences et micro–ondes de SiH4 correspondant aux transitions rotationnelles 'interdites' ΔJ = 0 entre les multiplets de niveaux de distorsion centrifuge, en employant la méthode de double résonance infrarouge–micro-onde dans une cavité laser.