This Letter reports on a search for off-shell production of the Higgs boson using 139 fb−1 of pp collision data at √s = 13 TeV collected by the ATLAS detector at the Large Hadron Collider. The signature is a pair of Z bosons, with contributions from both the production and subsequent decay of a virtual Higgs boson and the interference of that process with other processes. The two observable final states are Z Z → 4 and Z Z → 22ν with = e or μ. In the Z Z → 4 final state, a dense Neural Network is used to enhance analysis sensitivity with respect to matrix element-based discrimination. The backgroundonly hypothesis is rejected with an observed (expected) significance of 3.3 (2.2) standard deviations, representing experimental evidence for off-shell Higgs boson production. Assuming that no new particles enter the production of the virtual Higgs boson, its total width can be deduced from the measurement of its off-shell production cross-section. The measured total width of the Higgs boson is 4.5+3.3 −2.5 MeV, and the observed (expected) upper limit on the total width is found to be 10.5 (10.9) MeV at 95% confidence level.

Aad, G., Abbott, B., Abeling, K., Abidi, S., Aboulhorma, A., Abramowicz, H., et al. (2023). Evidence of off-shell Higgs boson production from ZZ leptonic decay channels and constraints on its total width with the ATLAS detector. PHYSICS LETTERS. SECTION B, 846, 1-29 [10.1016/j.physletb.2023.138223].

Evidence of off-shell Higgs boson production from ZZ leptonic decay channels and constraints on its total width with the ATLAS detector

Alberghi, G. L.;Alfonsi, F.;Bindi, M.;Boscherini, D.;Cabras, G.;Carratta, G.;Cavalli, N.;De Castro, S.;Fabbri, F.;Fabbri, L.;Franchini, M.;Gabrielli, A.;Lasagni Manghi, F.;Massa, L.;Polini, A.;Rinaldi, L.;Romano, M.;Sbarra, C.;Sbrizzi, A.;Semprini-Cesari, N.;Sioli, M.;Todome, K.;Valentinetti, S.;Villa, M.;Vittori, C.;Vivarelli, I.;Zoccoli, A.;
2023

Abstract

This Letter reports on a search for off-shell production of the Higgs boson using 139 fb−1 of pp collision data at √s = 13 TeV collected by the ATLAS detector at the Large Hadron Collider. The signature is a pair of Z bosons, with contributions from both the production and subsequent decay of a virtual Higgs boson and the interference of that process with other processes. The two observable final states are Z Z → 4 and Z Z → 22ν with = e or μ. In the Z Z → 4 final state, a dense Neural Network is used to enhance analysis sensitivity with respect to matrix element-based discrimination. The backgroundonly hypothesis is rejected with an observed (expected) significance of 3.3 (2.2) standard deviations, representing experimental evidence for off-shell Higgs boson production. Assuming that no new particles enter the production of the virtual Higgs boson, its total width can be deduced from the measurement of its off-shell production cross-section. The measured total width of the Higgs boson is 4.5+3.3 −2.5 MeV, and the observed (expected) upper limit on the total width is found to be 10.5 (10.9) MeV at 95% confidence level.
2023
Aad, G., Abbott, B., Abeling, K., Abidi, S., Aboulhorma, A., Abramowicz, H., et al. (2023). Evidence of off-shell Higgs boson production from ZZ leptonic decay channels and constraints on its total width with the ATLAS detector. PHYSICS LETTERS. SECTION B, 846, 1-29 [10.1016/j.physletb.2023.138223].
Aad, G.; Abbott, B.; Abeling, K.; Abidi, S.H.; Aboulhorma, A.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Abusleme Hoffman, A.C.; Acharya, B.S.; Adam Bo...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/953852
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