Is the Higgs total decay width equal to the SM 4.1 MeV? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title
Is the Higgs total decay width equal to the SM 4.1 MeV?
Plain
The width of the Higgs measures how fast it decays and counts every decay, including decays to unknown particles. The SM predicts 4.1 MeV, far too narrow to resolve directly at the LHC.
Precise · changed · core
Revision 1: Determine $\Gamma_H$ with $\le 5\ \mathrm{percent}$ uncertainty (SM: $4.1\ \mathrm{MeV}$). CMS used off-shell $H* \to \mathrm{ZZ}$ production to obtain $\Gamma_H=3.2+2.4-1.7\ \mathrm{MeV}$ (Nature Physics 18, 1329, 2022), a method that assumes equal coupling modifiers on and off shell. An answer is a model-independent $\Gamma_H$, which bounds the total rate of undetected and invisible decays.
Revision 2: Determine $\Gamma_H$ with $\le 5\%$ uncertainty (SM: $4.1\ \mathrm{MeV}$). CMS used off-shell $H* \to \mathrm{ZZ}$ production to obtain $\Gamma_H=3.2+2.4-1.7\ \mathrm{MeV}$ (Nature Physics 18, 1329, 2022), a method that assumes equal coupling modifiers on and off shell. An answer is a model-independent $\Gamma_H$, which bounds the total rate of undetected and invisible decays.
Settled by
A Higgs-factory measurement of $\sigma(e+ e- \to \mathrm{ZH})$ by the recoil-mass method combined with $\mathrm{BR}(H \to \mathrm{ZZ}*)$ or $\mathrm{BR}(H \to \mathrm{WW}*)$, giving $\Gamma_H$ without model assumptions at the percent level.
Kind
well-posed
Answer type
value
References
(empty)
Literature status
open
Status note
The 2022 CMS off-shell result agrees with the SM within errors of about 60 percent.
Posed since
(empty)

Decisions