Low-mass Higgs decays to four leptons at one loop and beyond

TL;DR

This paper provides a detailed theoretical analysis of Higgs boson decays to four leptons, incorporating full one-loop electroweak corrections and dominant higher-order contributions, crucial for precision measurements at colliders.

Contribution

It offers the first comprehensive calculation of Higgs decay widths to four leptons including full one-loop and significant multi-loop electroweak corrections, considering lepton mass effects.

Findings

Enhanced precision in Higgs decay width predictions.

Quantitative impact of higher-order corrections on decay rates.

Relevance of lepton mass effects, especially for tau leptons.

Abstract

The ongoing searches for Higgs-boson signals in data taken at the CERN LHC and the Fermilab Tevatron crucially rely on the decay channels H -> Z l l and H -> W l nu. We present a precision study of the partial widths of these decay channels including the full one-loop electroweak corrections and the dominant contributions at two and three loops, of O(G_F^2 m_t^4), O(G_F m_t^2 alpha_s), and O(G_F m_t^2 alpha_s^2). Since the invariant mass of the off-shell intermediate boson is relatively low in the mass window 115 GeV < m_H < 129 GeV of current interest, lepton mass effects are relevant, especially for the tau lepton.