Matous Vozak, Pedro Fernandez Manteca ,"Higgs -> WW off-shell and Higgs width measurements" [ATLAS, CMS]

by Matous Vozak (CERN), Pedro Fernandez Manteca (CERN)

Thursday 4 Jun 2026, 11:00 → 13:00 Europe/Zurich

4/2-011 - TH common room (CERN)

Abstract:

The latest Run 2 results from the ATLAS and CMS Collaborations on measurements of the Higgs boson total decay width using the WW->lnulnu final state will be presented. These analyses exploit off-shell Higgs boson production to probe the Higgs width, lifetime, and couplings in a high-energy regime that is sensitive to possible effects beyond the Standard Model. By comparing off-shell and on-shell Higgs boson production rates, both experiments provide constraints in a channel orthogonal to the H ZZ measurements.

We will review the ATLAS result [arXiv:2504.07710], which sets an observed 95% CL upper limit of 13.1 MeV on the Higgs boson width, and the CMS result [arXiv:2601.05168], which sets a corresponding limit of 9.9 MeV. The talk will cover the extraction of the width in gluon-gluon fusion and vector-boson fusion, the impact of signal-background interference, the theoretical precision of the relevant processes, and the differences between the ATLAS and CMS analysis strategies. We will also discuss the intricacies of the statistical interpretation caused by the non-linear model dependences involved, and highlight possible improvements for future measurements.

Pedro Fernandez Manteca:

Pedro Fernandez Manteca is a Research Fellow at CERN as a member of the CMS Collaboration. After obtaining his PhD at the University of Cantabria (Spain), he held a postdoctoral position at Rice University (US) and a Distinguished Researcher fellowship at Fermilab. His research focuses on precision Higgs boson measurements, Standard Model physics, and searches for physics beyond the Standard Model. He currently co-coordinates a physics subgroup at CMS covering searches for exotic physics with non-hadronic final states.

Matous Vozak:

Matous Vozak is an applied fellow at CERN working on the ATLAS Collaboration. He received his PhD at the University of Manchester during which he worked on several inclusive measurements of Standard Model processes with 0-4 lepton final states, with particular focus on the maximised reinterpretation of these measurements. After obtaining his PhD he became a postdoctoral researcher at Nikhef (Amsterdam). In this period, he was an analysis contact for ATLAS Run2 measurement of the Higgs boson total decay width in WW di-leptonic channel highlighted in this talk.