2026-06-28T15:18:45Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/45202023-08-28T01:34:59Zcom_20.500.14352_14col_20.500.14352_15

00925njm 22002777a 4500 dc Edwards, D. author Stevens, D. author Cheong, Z. author Graves, V. author Gorfinkiel, J. D. author Blanco Ramos, Francisco author García, G. author Brunger, M. J. author White, R. D. author Sullivan, J. P. author 2021-10-12 The present paper provides a joint experimental and theoretical study of positron scattering from pyrazine. Experimental data were measured employing a low-energy positron beamline, and covered an energy range from 1 to 79 eV. Cross sections were measured for total scattering, total elastic scattering, positronium formation, direct ionization, and the sum of the total discrete electronic-state excitation processes. In addition, measured total electronic excitation cross sections for the individual 1(1)B3u, 1(1)B2u, 1(1)B1u, and 2(1)B2u states are also reported. Finally, experimental elastic differential cross sections (DCSs), here in the energy range 1-20 eV, are also presented. Results from two theoretical approaches are given: the R-matrix approach and the independent atom method with screening corrected additivity rule and interference terms. Where a comparison between our experimental and theoretical results could be made, the level of accord varied from being quite good to marginal depending on the actual scattering process under consideration. Last, a comparison between the present elastic DCS results and those from our earlier study on positron scattering from pyrimidine [Palihawadana et al., Phys. Rev. A 88, 012717 (2013)] showed a somewhat unexpected level of agreement. 2469-9926 10.1103/PhysRevA.104.042807 https://hdl.handle.net/20.500.14352/4520 https://doi.org/10.1103/PhysRevA.104.042807 https://journals.aps.org/ Positron scattering from pyrazine