$Z, W^{\pm}$ rapidity distributions at NNLL and beyond

Abstract

In this article, we have studied threshold effects on rapidity distributions of massive gauge bosons ($Z, W^{\pm}$) in the Standard Model at the Large Hadron Collider. By exploiting the universal behavior of soft gluon emissions in the threshold region, we resum the large threshold logarithms arising in the rapidity distribution at next-to-next-to leading logarithmic accuracy and match them to next-to-next-to leading order in QCD. We adapt the double Mellin approach to resum both threshold variables corresponding to partonic threshold and rapidity consistently within the standard QCD framework. Furthermore, we have studied in detail the numerical impact of these threshold effects on the rapidity distribution of massive gauge bosons and found a better perturbative convergence in the resummed rapidity spectrum. As a by-product, we also provide all the perturbative ingredients to extend the analysis to next-to-next-to-next-to leading logarithmic accuracy. As a first application of these third order ingredients, we have estimated their effects by matching them with the third order soft-virtual results. Our results will be useful to understand and possibly constrain parton distributions using the rapidity spectrum.