: The dark photon A^{'} and the dark Higgs boson h^{'} are hypothetical particles predicted in many dark sector models. We search for the simultaneous production of A^{'} and h^{'} in the dark Higgsstrahlung process e^{+}e^{-}→A^{'}h^{'} with A^{'}→μ^{+}μ^{-} and h^{'} invisible in electron-positron collisions at a center-of-mass energy of 10.58 GeV in data collected by the Belle II experiment in 2019. With an integrated luminosity of 8.34 fb^{-1}, we observe no evidence for signal. We obtain exclusion limits at 90% Bayesian credibility in the range of 1.7-5.0 fb on the cross section and in the range of 1.7×10^{-8}-200×10^{-8} on the effective coupling ϵ^{2}×α_{D} for the A^{'} mass in the range of 4.0 GeV/c^{2}<9.7 GeV/c^{2} and for the h^{'} mass M_{h^{'}}
Abudinén, F., Adachi, I., Aggarwal, L., Aihara, H., Akopov, N., Aloisio, A., et al. (2023). Search for a Dark Photon and an Invisible Dark Higgs Boson in μ^{+}μ^{-} and Missing Energy Final States with the Belle II Experiment. PHYSICAL REVIEW LETTERS, 130(7), 071804 [10.1103/PhysRevLett.130.071804].
Search for a Dark Photon and an Invisible Dark Higgs Boson in μ^{+}μ^{-} and Missing Energy Final States with the Belle II Experiment
Bernieri, EMembro del Collaboration Group
;Branchini, PMembro del Collaboration Group
;Budano, AMembro del Collaboration Group
;Bussino, SMembro del Collaboration Group
;De Pietro, G
Writing – Original Draft Preparation
;Laurenza, MWriting – Original Draft Preparation
;Martini, AMembro del Collaboration Group
;
2023-01-01
Abstract
: The dark photon A^{'} and the dark Higgs boson h^{'} are hypothetical particles predicted in many dark sector models. We search for the simultaneous production of A^{'} and h^{'} in the dark Higgsstrahlung process e^{+}e^{-}→A^{'}h^{'} with A^{'}→μ^{+}μ^{-} and h^{'} invisible in electron-positron collisions at a center-of-mass energy of 10.58 GeV in data collected by the Belle II experiment in 2019. With an integrated luminosity of 8.34 fb^{-1}, we observe no evidence for signal. We obtain exclusion limits at 90% Bayesian credibility in the range of 1.7-5.0 fb on the cross section and in the range of 1.7×10^{-8}-200×10^{-8} on the effective coupling ϵ^{2}×α_{D} for the A^{'} mass in the range of 4.0 GeV/c^{2}<9.7 GeV/c^{2} and for the h^{'} mass M_{h^{'}}I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
