549 citations · 2.7k across the 57 of their papers we have counts for
57 papers
Total Born cross section of -pair production by an electron in the Coulomb field of a nucleus
Roman N. Lee, Alexey A. Lyubyakin, Vladimir A. Smirnov
We calculate the total Born cross section of the -pair production by an electron in the field of a nucleus (trident process) using the modern multiloop methods. For general…
Master Integrals for Four-Loop Massless Form Factors
Roman N. Lee, Andreas von Manteuffel, Robert M. Schabinger +3
We present analytical results for all master integrals for massless three-point functions, with one off-shell leg, at four loops. Our solutions were obtained using differential equ…
Two-loop corrections to Lamb shift and hyperfine splitting in hydrogen via multi-loop methods
Petr A. Krachkov, Roman N. Lee
We revisit the contributions of order and , respectively, to the Lamb shift and to the hyperfine splitting from mixed self-energy-vacuum-polarization diagr…
Charge asymmetry in the spectra of bremsstrahlung and pair production
Petr A. Krachkov, Roman N. Lee
We calculate the first Coulomb correction to the spectra of two processes: the electron bremsstrahlung and electron-positron photoproduction in the Coulomb field. We show that, in…
Four-loop HQET propagators from the DRA method
Roman N. Lee, Andrey F. Pikelner
We use dimensional recurrence relations and analyticity to calculate four-loop propagator-type master integrals in the heavy-quark effective theory. Compared to previous applicatio…
Four-loop QCD cusp anomalous dimension at small angle
Andrey G. Grozin, Roman N. Lee, Andrey F. Pikelner
We calculate the small angle expansion of the four-loop QCD cusp anomalous dimension. As a byproduct of our calculation, we also obtain the four-loop anomalous dimension of the hea…