Speaker
Description
A search for non-resonant Higgs boson pair (𝐻𝐻) production is presented, in which one of the Higgs bosons decays to a b-quark pair (𝑏̄𝑏) and the other decays to 𝑊𝑊∗, or 𝑍𝑍∗, or 𝜏+𝜏− , with in each case a final state with 𝑙𝑙 + neutrinos (𝑙 = 𝑒, 𝜇). Both gluon-gluon fusion and vector boson fusion are considered as production modes. Data recorded by the ATLAS detector in proton-proton collisions at a centre-of-mass energy of 13 TeV at the Large Hadron Collider, corresponding to an integrated luminosity of 140 fb−1, are used in this analysis. Events are selected to have exactly two 𝑏-tagged jets and two leptons with opposite electric charge and a large transverse missing energy (𝐸missT ) in the final state. These events are classified using multivariate analysis algorithms to separate the 𝐻𝐻 events from other Standard Model processes. No evidence of the signal is found. The observed (expected) upper limit on the cross-section for non-resonant Higgs boson pair production is determined to be 9.6 (16.2) times the Standard Model prediction at 95% confidence level. Likelihood scans for the Higgs boson self-interaction coupling parameter 𝜅𝜆 and the quadrilinear coupling parameter 𝜅2𝑉 are also performed in this analysis, constraining these parameters to be within the ranges [−6.2, 13.3] and [−0.17, 2.4], respectively, at 95% confidence level.
