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arXiv · 1812.01004

The Path to $0.01\%$ Theoretical Luminosity Precision for the FCC-ee

S. Jadach·W. Płaczek·M. Skrzypek·B. F. L. Ward·S. A. Yost
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Abstract

The current status of the theoretical precision for the Bhabha luminometry is critically reviewed and pathways are outlined to the requirement targeted by the FCC-ee precision studies. Various components of the pertinent error budget are discussed in detail -- starting from the context of the LEP experiments, through their current updates, up to prospects of their improvements for the sake of the FCC-ee. It is argued that with an appropriate upgrade of the Monte Carlo event generator BHLUMI and/or other similar MC programs calculating QED effects in the low angle Bhabha process, the total theoretical error of $0.01\%$ for the FCC-ee luminometry can be reached. A new study of the $Z$ and $s$-channel $\gamma$ exchanges within the angular range of the FCC-ee luminometer using the BHWIDE Monte Carlo was instrumental in obtaining the above result. Possible ways of BHLUMI upgrade are also discussed.

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S. Jadach, W. Płaczek, M. Skrzypek, B. F. L. Ward, S. A. Yost. 2018-12-03. The Path to $0.01\%$ Theoretical Luminosity Precision for the FCC-ee. https://doi.org/10.1016/j.physletb.2019.01.012

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