Faculty and Student Publications
Document Type
Article
Publication Date
4-1-2021
Abstract
We present a search for the dark photon A′ in the B0 → A′A′ decays, where A′ subsequently decays to e+e−, μ+μ−, and π+π−. The search is performed by analyzing 772 × 106BB¯ events collected by the Belle detector at the KEKB e+e− energy-asymmetric collider at the ϒ(4S) resonance. No signal is found in the dark photon mass range 0.01 GeV/c2 ≤ mA′ ≤ 2.62 GeV/c2, and we set upper limits of the branching fraction of B0 → A′A′ at the 90% confidence level. The products of branching fractions, ℬ(B0→A′A′)×ℬ(A′→e+e−)2 and ℬ(B0→A′A′)×ℬ(A′→μ+μ−)2, have limits of the order of 10−8 depending on the A′ mass. Furthermore, considering A′ decay rate to each pair of charged particles, the upper limits of ℬ (B→ A′ A′) are of the order of 10−8–10−5. From the upper limits of ℬ (B→ A′ A′) , we obtain the Higgs portal coupling for each assumed dark photon and dark Higgs mass. The Higgs portal couplings are of the order of 10−2–10−1 at mh′≃mB0 ± 40 MeV/c2 and 10−1–1 at mh′≃mB0 ± 3 GeV/c2. [Figure not available: see fulltext.]
Relational Format
journal article
Recommended Citation
The BELLE collaboration, Park, S.-H., Kwon, Y.-J., Adachi, I., Aihara, H., Al Said, S., Asner, D. M., Atmacan, H., Aushev, T., Ayad, R., Babu, V., Behera, P., Bennett, J., Bessner, M., Bhardwaj, V., Bhuyan, B., Bilka, T., Biswal, J., Bonvicini, G., … Zhulanov, V. (2021). Search for the dark photon in B0 → A′A′, A′ → e+e−, μ+μ−, and π+π− decays at Belle. Journal of High Energy Physics, 2021(4), 191. https://doi.org/10.1007/JHEP04(2021)191
DOI
10.1007/JHEP04(2021)191
Accessibility Status
Searchable text