Search for triple Higgs boson production in the 6⁢ final state using ⁢ collisions at √ =13 TeV with the ATLAS detector

UNSPECIFIED (2025) Search for triple Higgs boson production in the 6⁢ final state using ⁢ collisions at √ =13  TeV with the ATLAS detector. Physical Review D, 111 (3): 032006. ISSN 1550-7998

Abstract

A search for the production of three Higgs bosons (⁡⁡) in the ⁢ ¯ ⁢⁢ ¯ ⁢⁢ ¯ final state is presented. The search uses 126  fb−1 of proton-proton collision data at √ =13  TeV collected with the ATLAS detector at the Large Hadron Collider. The analysis targets both nonresonant and resonant production of ⁡⁡. The resonant interpretations primarily consider a cascade decay topology of →⁢ →⁡⁡ with masses of the new scalars and up to 1.5 and 1 TeV, respectively. In addition to scenarios where is off-shell, the nonresonant interpretation includes a search for Standard Model ⁡⁡ production, with limits on the trilinear and quartic Higgs self-coupling set. No evidence for ⁡⁡ production is observed. An upper limit of 59 fb is set, at the 95% confidence level, on the cross section for Standard Model ⁡⁡ production.