https://scholars.lib.ntu.edu.tw/handle/123456789/606619
標題: | Search for the dark photon in B 0 → A′A′, A′ → e + e ?, μ + μ ?, and π + π ? decays at Belle | 作者: | PAO-TI CHANG et al. WEI-SHU HOU et al. |
關鍵字: | B physics; Beyond Standard Model; e+-e- Experiments; Rare decay; | 公開日期: | 2021 | 卷: | 2021 | 期: | 4 | 來源出版物: | Journal of High Energy Physics | 摘要: | 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 ?(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, ?(B0→A′A′)×?(A′→e+e?)2 and ?(B0→A′A′)×?(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→ A′ A′) are of the order of 10?8–10?5. From the upper limits of ? (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.] ? 2021, The Author(s). |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85104718575&doi=10.1007%2fJHEP04%282021%29191&partnerID=40&md5=631bcc2badd852f2fde3e745534660e3 https://scholars.lib.ntu.edu.tw/handle/123456789/606619 |
ISSN: | 10298479 | DOI: | 10.1007/JHEP04(2021)191 |
顯示於: | 物理學系 |
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