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DY: Dynamik und Statistische Physik
DY 22: Quantum Dynamics II
DY 22.3: Vortrag
Dienstag, 28. März 2006, 11:30–11:45, H\"UL 186
Relevance of the electronic environment for the neutron scattering behavior of protons — •Tyno Abdul-Redah1,2, Aris C. Chatzidimitriou-Dreismann3, and Matthias Krzystyniak3 — 1ISIS Facility, Rutherford Appleton Laboratory, UK. — 2School of Physical Sciences, The University of Kent at Canterbury, Canterbury, UK. — 3Inst. f. Chemie, TU Berlin, Berlin, Germany.
A large number of neutron Compton scattering (NCS) experiments on hydrogen containing materials like liquid water, metal hydrogen systems and organic compounds has been reported on where a striking effect of a strong neutron proton scattering cross section shortfall has been found (for an overview, see [1]). This effect - which has been very recently confirmed using electron-proton Compton scattering on organic polymers [2] - was attributed to the existence of short lived protonic quantum entanglement and/or to the breakdown of the Born-Oppenheimer approximation during the scattering process. Recent NCS experiments on various metal hydrogen systems strongly indicate the relevance of the electronic environment surrounding the proton. Concretely, changing the electronic charge density around or the bonding conditions of the protons leads to different cross section anomalies in those materials. It is concluded that the electronic environment determines the decoherence process of the protons thus leading to these different anomalous shortfalls.
[1] T. Abdul-Redah et al., Neutron News 15 (2004) 14.
[2] C. A. C.-Dreismann et al., Phys. Rev. Lett. 91 (2003) 057403.
[3] T. Abdul-Redah et al., J. Alloys Compd. (2005), in press.