Towards a combination of LHC and TeVatron W-boson mass measurements

In this note methodological and modelling considerations towards a combination of the ATLAS, CDF and D0 measurements of the 𝑊-boson mass are discussed. As they were performed at different moments in time, each measurement employed different assumptions for the modelling of 𝑊-boson production and decay, as well as different fits of the parton distribution functions of the proton (PDFs). Methods are presented to accurately evaluate the effect of PDFs and other modelling variations on existing measurements, allowing to extrapolate them to any PDF set and to evaluate the corresponding uncertainties. Based on this approach, the measurements can be corrected to a common modelling reference and to the same PDFs, and subsequently combined accounting for PDF correlations in a quantitative way.