Abstract

The $^{1}\mathrm{P}^{\mathrm{o}}$ shape resonance of ${\mathrm{H}}^{\mathrm{\ensuremath{-}}}$ has been studied in moderate motional electric fields by Doppler-tuning the photon energy absorbed by a 650-MeV ${\mathrm{H}}^{\mathrm{\ensuremath{-}}}$ beam crossed by the fourth-harmonic beam of a Nd:YAG laser (YAG denotes yttrium aluminum garnet). The resonance parameters are remarkably insensitive to electric fields in the range from 120 to 240 kV/cm. Our measurements reveal that the width of the shape resonance may decrease from its zero-field value, on average, by (3.3\ifmmode\pm\else\textpm\fi{}0.9)% in this electric field regime. This observation contradicts the (naive) expectation that perturbation of the resonance by an electric field should promote more rapid decay, and hence greater width. Interpretations are given in terms of (a) Stark mixing with narrower singlet states and (b) tunneling through the potential barrier in hyperspherical coordinates.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.