In this paper we present a calculation of the γ+j process at next-to-next-to-leading order (NNLO) in QCD and compare the resulting predictions to 8 TeV CMS data. We find good agreement with the shape of the photon pT spectrum, particularly after the inclusion of additional electroweak corrections, but there is a tension between the overall normalization of the theoretical prediction and the measurement. We use our results to compute the ratio of Z(→ℓ+ℓ−)+j to γ+j events as a function of the vector boson transverse momentum at NNLO, a quantity that is used to normalize Z(→νν)+j backgrounds in searches for dark matter and supersymmetry. Our NNLO calculation significantly reduces the theoretical uncertainty on this ratio, thus boosting its power for future searches of new physics.
@article{arxiv.1703.10109,
title = {Driving Miss Data: Going up a gear to NNLO},
author = {John M. Campbell and R. Keith Ellis and Ciaran Williams},
journal= {arXiv preprint arXiv:1703.10109},
year = {2017}
}