Limits on the Higgs boson lifetime and width from its decay to four charged leptons

TL;DR

This paper sets new experimental limits on the Higgs boson's lifetime and width using decay to four charged leptons, employing data from the CMS experiment at the LHC, and includes considerations of anomalous couplings.

Contribution

It introduces a novel method to measure the Higgs width using off-shell production and anomalous couplings, providing tighter constraints than previous measurements.

Findings

Higgs boson lifetime < 1.9E-13 seconds at 95% CL

Higgs width < 46 MeV at 95% CL

Constraint on anomalous coupling parameter f[LQ] < 3.8E-3

Abstract

Constraints on the lifetime and width of the Higgs boson are obtained from H to ZZ to 4 lepton events using data recorded by the CMS experiment during the LHC run 1 with an integrated luminosity of 5.1 and 19.7 inverse femtobarns at a center-of-mass energy of 7 and 8 TeV, respectively. The measurement of the Higgs boson lifetime is derived from its flight distance in the CMS detector with an upper bound of tau[H] < 1.9E-13 s at the 95% confidence level (CL), corresponding to a lower bound on the width of Gamma[H] > 3.5E-9 MeV. The measurement of the width is obtained from an off-shell production technique, generalized to include anomalous couplings of the Higgs boson to two electroweak bosons. From this measurement, a joint constraint is set on the Higgs boson width and a parameter f[LQ] that expresses an anomalous coupling contribution as an on-shell cross-section fraction. The limit on the Higgs boson width is Gamma[H] < 46 MeV with f[LQ] unconstrained and Gamma[H] < 26 MeV for f[LQ] = 0 at the 95% CL. The constraint f[LQ] < 3.8E-3 at the 95% CL is obtained for the expected standard model Higgs boson width.