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

Abstract

Constraints on the lifetime and width of the Higgs boson are obtained from H → ZZ → 4l events using data recorded by the CMS experiment during the LHC run 1 with an integrated luminosity of 5.1 and 19.7 fb −1 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 τ H < 1.9 × 10 −13 s at the 95% confidence level (C.L.), corresponding to a lower bound on the width of Γ H > 3.5 × 10 −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 ΛQ that expresses an anomalous coupling contribution as an on-shell cross-section fraction. The limit on the Higgs boson width is Γ H < 46 MeV with f ΛQ unconstrained and Γ H < 26 MeV for f ΛQ ¼ 0 at the 95% C.L. The constraint f ΛQ < 3.8 × 10 −3 at the 95% C.L. is obtained for the expected standard model Higgs boson width.

QCD corrections to vector boson pair production in gluon fusion including interference effects with off-shell Higgs at the LHC

“…Subsequent experimental analyses used this method to constrain the Higgs boson width to be less than a few times its Standard Model value [7][8][9]. This is to be compared with the direct constraints on the Higgs width that can be obtained from fitting the invariant mass distributions of four leptons or a photon pair around the Higgs mass.…”

“…While this is a plausible hypothesis which can be justified if universal soft QCD radiation provides a dominant source of radiative corrections [26,27], it is important to verify it by an explicit computation. Such verification as well as the computation of the realistic QCD enhancement factor for the interference accounting for off-shell effects, vector boson decays and fiducial cuts used by ATLAS and CMS collaborations [7][8][9], become increasingly important since the LHC experiments are posed to push the off-shell measurements to a new level of precision.…”

Search for di-Higgs production with the ATLAS detector

“…Further studies of its properties [5][6][7][8], such as the measurement of its spin and couplings, showed no significant deviations from the SM expectation. The discovery of the Higgs boson provided an important window on physics beyond the SM.…”

Two Higgs bosons near 125 GeV in the NMSSM: beyond the narrow width approximation

“…We further made sure that a point only got through the scan if it satisfied the limits from measurements of the EDMs, computed intrinsically by NMSSMCALC. Finally, the CMS and ATLAS collaborations have performed measurements of the total width of the h obs by analysing its off-shell production and subsequent decays in the Z Z and W + W − channels [55][56][57]. The most recent observed 95% confidence level upper limit for the two channels combined is 13 MeV.…”