Sequential three-body breakup of a CO$_{\mathrm{2}}^{\mathrm{+}}$ beam
ORAL
Abstract
The dissociative double ionization of a CO$_{\mathrm{2}}^{\mathrm{+}}$ beam leading to the three-body fragmentation channel C$^{\mathrm{+}} \quad +$ O$^{\mathrm{+}} \quad +$ O$^{\mathrm{+}}$ can have its origin in either a sequential or concerted process. In case of the sequential mechanism, the first step is a two-body breakup into CO$^{\mathrm{2+}} \quad +$ O$^{\mathrm{+}}$, followed by a second step wherein CO$^{\mathrm{2+}}$ further fragments into C$^{\mathrm{+}} \quad +$ O$^{\mathrm{+}}$. The rotation of the CO$^{\mathrm{2+}}$ formed during the first step [1] has been used to discriminate between the sequential and non-sequential mechanisms in experiments which employ multi-coincidence momentum imaging techniques for detecting recoil fragments [2,3]. We propose a novel way to look at this discriminating feature in terms of the angle of rotation of the CO$^{\mathrm{2+}}$ intermediate. We will also discuss the implications on the measured momentum distribution of detecting indistinguishable fragments in a coincidence measurement. [1] E. Krishnakumar \textit{et al.} ,Phys. Rev. A \textbf{44}, R4098 (1991). [2] N. Neumann \textit{et al.} ,Phys. Rev. Lett. \textbf{104}, 103201 (2010). [3] C. Wu \textit{et al.} ,Phys. Rev. Lett. \textbf{110}, 103601 (2013).
*This work was supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy. BJ was also supported by DOE-SCGF (DE-AC05-06OR23100).
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