EPJ Web Conf.
Volume 234, 2020International Workshop on “Flavour Changing and Conserving Processes” (FCCP2019)
|Number of page(s)||5|
|Published online||27 April 2020|
The 4-loop slope of the Dirac form factor
Dipartimento di Fisica e Astronomia, Università di Padova, Via Marzolo 8, I-35131 Padova, Italy
2 Istituto Nazionale Fisica Nucleare, Sezione di Padova, Via Marzolo 8, I-35131 Padova, Italy
a e-mail: email@example.com
b Talk given at “Flavour changing and conserving processes” 2019 (FCCP2019), 29-31 August 2019, Villa Orlandi, Anacapri, Capri, Italy.
Published online: 27 April 2020
The 4-loop contribution to the slope of the Dirac form factor in QED has been evaluated with 1100 digits of precision. The value is . We have also obtained a semi-analytical fit to the numerical value. The expression contains harmonic polylogiπ2iπ iπ arithms of argument , one-dimensional integrals of products of complete elliptic integrals and six finite parts of master integrals, evaluated up to 4800 digits. We show the correction to the energy levels of the hydrogen atom due to the slope.
© The Authors, published by EDP Sciences, 2020
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