A search for exotic decays of the Higgs boson 𝐻 into new scalar or pseudoscalar particles that subsequently decay into 𝑏-quarks is presented. The search considers 𝑍⁢𝐻 production with several decay scenarios for the Higgs boson; first to a pair of identical scalars, 𝐻 →2⁢𝑎 →4⁢𝑏, second to a pair of scalars with different masses (𝑚𝑎⁢1 <𝑚𝑎⁢2), either directly, 𝐻 →𝑎1⁢𝑎2 →4⁢𝑏, or via a longer decay chain, 𝐻 →𝑎1⁢𝑎2 →3⁢𝑎1 →6⁢𝑏. The analysis uses proton-proton collision data at √𝑠 =13  TeV collected with the ATLAS detector at the Large Hadron Collider, corresponding to an integrated luminosity of 140  fb−1. No significant excess above the Standard Model prediction is observed. The search sets upper limits at 95% confidence level on the ratio of the Higgs boson production cross section to the SM prediction times the branching ratio of Higgs bosons decaying into 4⁢𝑏 or 6⁢𝑏, between 4% and 25% for 𝜎⁡(𝑍⁢𝐻)/𝜎SM⁡(𝑍⁢𝐻)×ℬ⁡(𝐻→2⁢𝑎→4⁢𝑏), between 24% and 38% for 𝜎⁡(𝑍⁢𝐻)/𝜎SM⁡(𝑍⁢𝐻)×ℬ⁡(𝐻→𝑎1⁢𝑎2→4⁢𝑏), and between 10% and 20% for 𝜎⁡(𝑍⁢𝐻)/𝜎SM⁡(𝑍⁢𝐻)×ℬ⁡(𝐻→𝑎1⁢𝑎2→3⁢𝑎1→6⁢𝑏), depending on the masses of the scalar particles.

Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., Abicht, N. j., et al. (2025). Search for decays of the Higgs boson into scalar particles decaying into four or six 𝑏 quarks using 𝑝⁢𝑝 collisions at √𝑠 =13  TeV with the ATLAS detector. PHYSICAL REVIEW D, 112(7), 072005-1-072005-44 [10.1103/mzld-ldlt].

Search for decays of the Higgs boson into scalar particles decaying into four or six 𝑏 quarks using 𝑝⁢𝑝 collisions at √𝑠 =13  TeV with the ATLAS detector

Alfonsi, F.;Ballabene, E.;Bellagamba, L.;Bianco, G.;Boscherini, D.;Bruni, A.;Cardarelli, R.;Carratta, G.;Corchia, F.  A.;Cremonini, D.;De Castro, S.;Fabbri, F.;Fabbri, L.;Franchini, M.;Gabrielli, A.;Giacobbe, B.;Lasagni Manghi, F.;Levrini, G.;Nechaeva, S.;Polini, A.;Rinaldi, L.;Romano, M.;Sanzani, E.;Sbarra, C.;Sbrizzi, A.;Semprini-Cesari, N.;Sioli, M.;Todome, K.;Valentinetti, S.;Villa, M.;Vittori, C.;Vivarelli, I.;Zoccoli, A.;
2025

Abstract

A search for exotic decays of the Higgs boson 𝐻 into new scalar or pseudoscalar particles that subsequently decay into 𝑏-quarks is presented. The search considers 𝑍⁢𝐻 production with several decay scenarios for the Higgs boson; first to a pair of identical scalars, 𝐻 →2⁢𝑎 →4⁢𝑏, second to a pair of scalars with different masses (𝑚𝑎⁢1 <𝑚𝑎⁢2), either directly, 𝐻 →𝑎1⁢𝑎2 →4⁢𝑏, or via a longer decay chain, 𝐻 →𝑎1⁢𝑎2 →3⁢𝑎1 →6⁢𝑏. The analysis uses proton-proton collision data at √𝑠 =13  TeV collected with the ATLAS detector at the Large Hadron Collider, corresponding to an integrated luminosity of 140  fb−1. No significant excess above the Standard Model prediction is observed. The search sets upper limits at 95% confidence level on the ratio of the Higgs boson production cross section to the SM prediction times the branching ratio of Higgs bosons decaying into 4⁢𝑏 or 6⁢𝑏, between 4% and 25% for 𝜎⁡(𝑍⁢𝐻)/𝜎SM⁡(𝑍⁢𝐻)×ℬ⁡(𝐻→2⁢𝑎→4⁢𝑏), between 24% and 38% for 𝜎⁡(𝑍⁢𝐻)/𝜎SM⁡(𝑍⁢𝐻)×ℬ⁡(𝐻→𝑎1⁢𝑎2→4⁢𝑏), and between 10% and 20% for 𝜎⁡(𝑍⁢𝐻)/𝜎SM⁡(𝑍⁢𝐻)×ℬ⁡(𝐻→𝑎1⁢𝑎2→3⁢𝑎1→6⁢𝑏), depending on the masses of the scalar particles.
2025
Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., Abicht, N. j., et al. (2025). Search for decays of the Higgs boson into scalar particles decaying into four or six �� quarks using ��⁢�� collisions at √�� =13  TeV with the ATLAS detector. PHYSICAL REVIEW D, 112(7), 072005-1-072005-44 [10.1103/mzld-ldlt].
Aad, G.; Aakvaag, E.; Abbott, B.; Abdelhameed, S.; Abeling, K.; Abicht, N.  j.; Abidi, S.  h.; Aboelela, M.; Aboulhorma, A.; Abramowicz, H.; Abulaiti,...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/1049478
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