Higgs boson mass measurement using $H\to ZZ\to 4\ell$ decays at CMS

Abstract

A summary of the methods used to make a precision measurement of the Higgs boson mass is presented. The final mass value for the Higgs boson is measured to be $m_{\mathrm{H}}=125.26\pm 0.21\mathrm{GeV}$. This analysis considers the $\mathrm{H}\to \mathrm{ZZ}\to 4\ell$ channel ($\ell =e,\mu$), using proton-proton collision data collected in 2016 corresponding to an integrated luminosity of $35.9{\mathrm{fb}}^{-1}$ at $\sqrt{s}=13$ TeV by the CMS experiment at the LHC. A mass constraint is imposed on the invariant mass of the two leptons coming from the mostly on-shell Z boson to refit the lepton momenta and, hence, improve the measurement of the Higgs boson mass, per-event. The mass of the Higgs boson is extracted using a three-dimensional likelihood fit, which uses three observables per-event: (1) the refitted four-lepton invariant mass ($m_{4\ell }^{\prime }$), (2) the refitted four-lepton mass uncertainty (${\mathcal{D}}_{\mathrm{mass}}^{\prime }$), and (3) a matrix element-based kinematic discriminant (${\mathcal{D}}_{\mathrm{bkg}}^{\mathrm{kin}}$).

Talk presented at the 2019 Meeting of the Division of Particles and Fields of the American Physical Society (DPF2019), July 29 - August 2, 2019, Northeastern University, Boston, C1907293

References in corpus (4)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• Combined Measurement of the Higgs Boson Mass in $pp$ Collisions at $\sqrt{s}=7$ and 8 TeV with the ATLAS and CMS Experiments
• Measurements of properties of the Higgs boson decaying into the four-lepton final state in pp collisions at sqrt(s) = 13 TeV