Eur. Phys. J. D (2014) 68: 279
https://doi.org/10.1140/epjd/e2014-50072-0

Regular Article

Low-energy positron scattering from DNA nucleobases: the effects from permanent dipoles^*

¹ Department of Atomic, Molecular and Optical Physics, Faculty of Applied Physics and Mathematics, Gdansk University of Technology, ul. Narutowicza 11/12, 80-233 Gdansk, Poland
² Institute of Ion Physics, The University of Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria

^a Also at: Interdisciplinary Laboratory for Computational Science, FBK-CMM, via Sommarive 18, 38123 Povo, Trento, Italy
^b e-mail: j.franz@ucl.ac.uk
^c Also at: Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy

Received: 23 January 2014
Received in final form: 12 June 2014
Published online: 1 October 2014

Abstract

Ab initio quantum calculations for low-energy positron scattering from gas-phase isolated molecular nucleobases which are part of the DNA structure are presented and discussed over the range of 1 eV to 25 eV. The calculations report the integral cross sections (ICSs) and the momentum-transfer cross sections (MTCSs) for Adenine, Guanine, Thymine and Cytosine. The calculations show very clearly the important role of the dominant long-range interaction between the positron projectile and the permanent dipole-moments of the target molecules in deciding the relative sizes of the ICSs and MTCSs for the present series of molecules. Such results confirm the largely repulsive interaction between positron and DNA bases, which is nevertheless producing very large cross sections and marked deflection functions from the latter molecules.