Predictions for Higgs production at the Tevatron and the associated uncertainties

TL;DR

This paper updates Higgs production predictions at the Tevatron, quantifies uncertainties in key channels, and highlights the impact of these uncertainties on experimental exclusion limits.

Contribution

It provides a comprehensive analysis of theoretical uncertainties in Higgs production cross sections, especially for gluon-gluon fusion, at the Tevatron collider.

Findings

Cross sections are well-controlled in Higgs-strahlung processes.

Large uncertainties (~40%) affect gluon-gluon fusion predictions.

Experimental exclusion limits may need revision due to these uncertainties.

Abstract

We update the theoretical predictions for the production cross sections of the Standard Model Higgs boson at the Fermilab Tevatron collider, focusing on the two main search channels, the gluon-gluon fusion mechanism $gg \to H$ and the Higgs-strahlung processes $q \bar q \to VH$ with $V=W/Z$, including all relevant higher order QCD and electroweak corrections in perturbation theory. We then estimate the various uncertainties affecting these predictions: the scale uncertainties which are viewed as a measure of the unknown higher order effects, the uncertainties from the parton distribution functions and the related errors on the strong coupling constant, as well as the uncertainties due to the use of an effective theory approach in the determination of the radiative corrections in the $gg \to H$ process at next-to-next-to-leading order. We find that while the cross sections are well under control in the Higgs--strahlung processes, the theoretical uncertainties are rather large in the case of the gluon-gluon fusion channel, possibly shifting the central values of the next-to-next-to-leading order cross sections by more than $\approx 40%$. These uncertainties are thus significantly larger than the $\approx 10%$ error assumed by the CDF and D0 experiments in their recent analysis that has excluded the Higgs mass range $M_H=$162-166 GeV at the 95% confidence level. These exclusion limits should be, therefore, reconsidered in the light of these large theoretical uncertainties.