Speaker
Description
The high level of experimental precision achieved at hadron colliders requires competitive theoretical predictions in order to extract fundamental SM parameters, such as the W boson mass.
Theoretical efforts should therefore be directed towards relevant kinematic distributions, such as the transverse momentum (pT) spectrum of the W and Z bosons and their ratio.
In this talk, essentially based on our paper (JHEP 07 (2023) 104), I will discuss the combined QCD-QED transverse-momentum resummation formalism for weak vector boson production at hadron colliders. In particular, logarithmically enhanced terms originating from soft and/or collinear QCD and QED radiation are consistently evaluated and resummed at NNLL+NNLO in QCD with the inclusion of mixed QCD-QED effects at LL and pure QED effects at NLL, matched with a fixed-order full-EW NLO contribution (i.e. at a loop). A naive abelianisation of the well-established QCD formalism, which has been used in the literature to obtain the QED contributions for on-shell Z boson production, is not sufficient for on-shell W boson production due to the electric charge of the final state. In particular, for this situation, we have performed an abelianisation of the heavy quark resummation formalism, and thus properly resum also the QED soft radiation of the final state. The inclusion of this last contribution is thus the main original feature of our study. Numerical results at hadron colliders (Tevatron, LHC) are presented for the on-shell Z and W boson transverse-momentum distributions and their ratio, potentially relevant in the context of W boson mass extraction, showing a non-trivial shape modification caused by final-state radiation and QED effects up to the percent level.
