Berlin 2005 – wissenschaftliches Programm
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K: Kurzzeitphysik
K 6: Poster
K 6.1: Poster
Montag, 7. März 2005, 16:45–18:00, Poster HU
Anomalous neutron Compton scattering cross-section in zirkonium hydride from neutron-proton collisions on the attosecond-timescale. — •M. Krzystyniak1, T. Abdul-Redah2, J. Mayers3, and C.A. Chatzidimitriou-Dreismann1 — 1Stranski Laboratorium, Technical University Berlin — 2University of Kent, Canterbury, UK — 3ISIS Facility, Rutherford Appleton Laboratory, UK
The proton total neutron scattering cross-section σH was measured in ZrH2 using neutron Compton scattering (NCS) on VESUVIO (ISIS, UK). For the neutron proton collision at VESUVIO: Δ E ≅ 1−100 eV and ∣ q ∣ ≅ 30−200 Å1. This corresponds to the duration of the collision τsc ≅ 50−500 attoseconds. An angle (i.e. momentum transfer) dependent decrease of the total scattering cross section below the value for the conventional theory has been reported for NbH0.8 [1]. It was, criticized, that this could result if the incident neutron flux is not accounted for correctly in the data reduction [2]. However, in contrast to the NbH0.8 result, an angle independent decrease of σH is found thus strongly contradicting the argument outlined in [2] and justifying the data analysis procedure. The observed decreases of σH in NbH0.8 and ZrH2 are genuine and indicate the existence of quantum entangled states between adjacent protons and their decoherence due to coupling to surrounding electron densities. [1] E. B. Karlsson, T. Abdul-Redah, R. M. Streffer, B. Hjrvarsson, J. Mayers and C. A. Chatzidimitriou-Dreismann, Phys. Rev. B 67, 184108 (2003) [2] R. A. Cowley, J. Phys.: Condens. Matter 15, 4143 (2003)