Understand
We discuss the determination of electroweak parameters from hadron collider observables, focusing on the $W$ boson mass measurement.
- We revise the procedures adopted in the literature to include in the experimental analysis the uncertainty due to our imperfect knowledge of the proton structure.
- We show how the treatment of the proton parton density functions (PDFs) uncertainty as a source of systematic error, leads to the automatic inclusion in the fit of the bin-bin correlation of the kinematic distributions with respect to PDF variations.
- In the case of the determination of $M_W$ from the charged lepton transverse momentum distribution, we observe that the inclusion of this correlation factor yields a strong reduction of the PDF uncertainty, given a sufficiently good control over all the other error sources.