# Extra Lepton Pair Emission Corrections to Drell--Yan Processes in PHOTOS and SANC

Antropov, S. (The H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego~152, 31-342 Kraków, Poland) ; Arbuzov, A. (Bogoliubov Laboratory for Theoretical Physics, JINR, Dubna 141980, Russia) ; Sadykov, R. (Dzhelepov Laboratory of Nuclear Problems, JINR, Joliot-Curie str. 6, 141980~Dubna, Russia) ; Was, Z. (The H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego~152, 31-342 Kraków, Poland)

13 October 2017

Abstract: In the paper, we present results for the final-state emissions of lepton pairs in decays of heavy intermediate states such as $Z$ boson. Short presentations of \textsf{PHOTOS} and \textsf{SANC} algorithms and physics assumptions are given. Numerical distributions of relevance for LHC observables are shown. They are used in discussions of systematic errors in the predictions of pair emissions as implemented in the two programs. Suggestions for the future works are given. Present results confirm, that for the precision of 0.3\% level, in simulation of the final state, the pair emissions can be avoided. For the precision of 0.1--0.2\%, the results obtained with the presented programs should be sufficient. To cross precision tag of 0.1\%, the further work is however required.

Published in: Acta Physica Polonica B 48 (2017) 1469-1492