RT Journal Article T1 Positron scattering from pyrazine A1 Edwards, D. A1 Stevens, D. A1 Cheong, Z. A1 Graves, V. A1 Gorfinkiel, J. D. A1 Blanco Ramos, Francisco A1 García, G. A1 Brunger, M. J. A1 White, R. D. A1 Sullivan, J. P. AB 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. PB Amer Physical Soc SN 2469-9926 YR 2021 FD 2021-10-12 LK https://hdl.handle.net/20.500.14352/4520 UL https://hdl.handle.net/20.500.14352/4520 LA eng NO ©2021 American Physical Society. The authors would like to acknowledge R. Tranter for his ongoing technical support of the experimental apparatus used in these experiments. Funding is acknowledged from the Australian Research Council Discovery program (Grant No. DP190100696). V.G. acknowledges support from the EPSRC Doctoral Training Partnership EP/T518165/1. F.B. and G.G. acknowledge partial financial support from the Spanish Ministerio de Ciencia e Innovacion (Project No. PID2019-104727RB-C21) and CSIC (Project No. LINKA20085). NO Ministerio de Ciencia e Innovación (MICINN) NO Consejo Superior de Investigaciones Científicas (CSIC) NO Australian Research Council NO EPSRC Doctoral Training Partnership UK DS Docta Complutense RD 18 abr 2025