# Driving Miss Data: Going up a gear to NNLO

**Authors:** John M. Campbell, R. Keith Ellis, Ciaran Williams

arXiv: 1703.10109 · 2017-08-09

## TL;DR

This paper presents a NNLO QCD calculation of the gamma+jet process, compares it with 8 TeV CMS data, and improves the theoretical prediction's accuracy for background normalization in new physics searches.

## Contribution

The paper provides the first NNLO QCD calculation of gamma+jet production and demonstrates its impact on reducing uncertainties in background estimates for collider searches.

## Key findings

- Good agreement with photon p_T spectrum shape after electroweak corrections.
- Significant reduction in theoretical uncertainty for the Z/gamma ratio.
- Tension remains in overall normalization between theory and data.

## Abstract

In this paper we present a calculation of the $\gamma+j$ 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 $p_T$ 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 $Z(\to \ell^+\ell^-)+j$ to $\gamma+j$ events as a function of the vector boson transverse momentum at NNLO, a quantity that is used to normalize $Z(\rightarrow\nu\overline{\nu}) +j$ 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.

## Full text

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## Figures

11 figures with captions in the complete paper: https://tomesphere.com/paper/1703.10109/full.md

## References

51 references — full list in the complete paper: https://tomesphere.com/paper/1703.10109/full.md

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Source: https://tomesphere.com/paper/1703.10109