A search for the Higgs boson decay to a Z boson and a photon in the ℓℓ γ (ℓ=e,μ) final state is performed using pp collisions at s=13.6 TeV recorded with the ATLAS detector at the Large Hadron Collider during 2022–2024, corresponding to an integrated luminosity of 165 fb−1. The signal yield, normalised to the Standard Model prediction, is measured to be μ=0.9−0.6+0.7, compatible with the expected value of μ=1.0±0.7. This corresponds to an observed (expected) signal significance of 1.4 (1.5) standard deviations under the background-only hypothesis. This result is combined with that of a similar search performed with 140 fb−1 of s=13 TeV pp collisions to provide the best expected sensitivity to date to this rare decay, namely an observed (expected) signal strength of μ=1.3−0.5+0.6 (μ=1.0−0.5+0.6), corresponding to an observed (expected) significance of 2.5 (1.9) standard deviations. The measurement is consistent with the Standard Model expectation.

Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., Abicht, N.J., et al. (2026). Search for the Higgs boson decay to a Z boson and a photon in pp collisions at s=13 TeV and 13.6 TeV with the ATLAS detector. PHYSICS LETTERS. SECTION B, 876 [10.1016/j.physletb.2026.140313].

Search for the Higgs boson decay to a Z boson and a photon in pp collisions at s=13 TeV and 13.6 TeV with the ATLAS detector

Di Micco, B.;Di Nardo, R.;Montereali, F.;Orestano, D.;Orlandini, R.;
2026-01-01

Abstract

A search for the Higgs boson decay to a Z boson and a photon in the ℓℓ γ (ℓ=e,μ) final state is performed using pp collisions at s=13.6 TeV recorded with the ATLAS detector at the Large Hadron Collider during 2022–2024, corresponding to an integrated luminosity of 165 fb−1. The signal yield, normalised to the Standard Model prediction, is measured to be μ=0.9−0.6+0.7, compatible with the expected value of μ=1.0±0.7. This corresponds to an observed (expected) signal significance of 1.4 (1.5) standard deviations under the background-only hypothesis. This result is combined with that of a similar search performed with 140 fb−1 of s=13 TeV pp collisions to provide the best expected sensitivity to date to this rare decay, namely an observed (expected) signal strength of μ=1.3−0.5+0.6 (μ=1.0−0.5+0.6), corresponding to an observed (expected) significance of 2.5 (1.9) standard deviations. The measurement is consistent with the Standard Model expectation.
2026
Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., Abicht, N.J., et al. (2026). Search for the Higgs boson decay to a Z boson and a photon in pp collisions at s=13 TeV and 13.6 TeV with the ATLAS detector. PHYSICS LETTERS. SECTION B, 876 [10.1016/j.physletb.2026.140313].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11590/559056
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