Expected Precision of Higgs Boson Partial Widths within the Standard Model

TL;DR

This paper analyzes the uncertainties in predicting Higgs boson partial widths within the Standard Model, emphasizing perturbative calculations and input parameter uncertainties, and discusses future improvements from lattice QCD.

Contribution

It provides a systematic review of current uncertainties and forecasts the future precision of Higgs partial width predictions using lattice QCD improvements.

Findings

Perturbative calculations are accurate to parts-per-mil for major decay modes.

Main uncertainties stem from parameters alpha_s, m_b, and m_c.

Lattice QCD will significantly improve parameter determinations in the next decade.

Abstract

We discuss the sources of uncertainty in calculations of the partial widths of the Higgs boson within the Standard Model. The uncertainties come from two sources: the truncation of perturbation theory and the uncertainties in input parameters. We review the current status of perturbative calculations and note that these are already reaching the parts-per-mil level of accuracy for the major decay modes. The main sources of uncertainty will then come from the parametric dependences on alpha_s, m_b, and m_c. Knowledge of these parameters is systematically improvable through lattice gauge theory calculations. We estimate the precision that lattice QCD will achieve in the next decade and the corresponding precision of the Standard Model predictions for Higgs boson partial widths.