Shape Resonances in H2 as Photolysis Reaction Intermediates
| Autor: | Maximilian Beyer, Edcel J. Salumbides, K.-F. Lai, Wim Ubachs |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Physical Review Letters. 127 |
| ISSN: | 1079-7114 0031-9007 |
| Popis: | Shape resonances in ${\mathrm{H}}_{2}$, produced as reaction intermediates in the photolysis of ${\mathrm{H}}_{2}\mathrm{S}$ precursor molecules, are measured in a half-collision approach. Before disintegrating into two ground state H atoms, the reaction is quenched by two-photon Doppler-free excitation to the $\mathrm{F}$ electronically excited state of ${\mathrm{H}}_{2}$. For $J=13$, 15, 17, 19, and 21, resonances with lifetimes in the range of nano- to milliseconds were observed with an accuracy of 30 MHz (1.4 mK). The experimental resonance positions are found to be in excellent agreement with theoretical predictions when nonadiabatic and quantum electrodynamical corrections are included. This is the first time such effects are observed in collisions between neutral atoms. From the potential energy curve of the ${\mathrm{H}}_{2}$ molecule, now tested at high accuracy over a wide range of internuclear separations, the $s$-wave scattering length for singlet $\mathrm{H}(1s)+\mathrm{H}(1s)$ scattering is determined at $a={0.2735}_{31}^{39}$ ${a}_{0}$. |
| Databáze: | OpenAIRE |
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