Journal of High Energy Physics (Apr 2021)

Search for the dark photon in B 0 → A′A′, A′ → e + e − , μ + μ − , and π + π − decays at Belle

  • The BELLE collaboration,
  • S.-H. Park,
  • Y.-J. Kwon,
  • I. Adachi,
  • H. Aihara,
  • S. Al Said,
  • D. M. Asner,
  • H. Atmacan,
  • T. Aushev,
  • R. Ayad,
  • V. Babu,
  • P. Behera,
  • J. Bennett,
  • M. Bessner,
  • V. Bhardwaj,
  • B. Bhuyan,
  • T. Bilka,
  • J. Biswal,
  • G. Bonvicini,
  • A. Bozek,
  • M. Bračko,
  • T. E. Browder,
  • M. Campajola,
  • L. Cao,
  • D. Červenkov,
  • M.-C. Chang,
  • P. Chang,
  • A. Chen,
  • B. G. Cheon,
  • K. Chilikin,
  • H. E. Cho,
  • K. Cho,
  • S.-J. Cho,
  • S.-K. Choi,
  • Y. Choi,
  • S. Choudhury,
  • D. Cinabro,
  • S. Cunliffe,
  • S. Das,
  • N. Dash,
  • G. De Nardo,
  • F. Di Capua,
  • J. Dingfelder,
  • Z. Doležal,
  • T. V. Dong,
  • S. Eidelman,
  • D. Epifanov,
  • D. Ferlewicz,
  • B. G. Fulsom,
  • R. Garg,
  • V. Gaur,
  • A. Garmash,
  • A. Giri,
  • P. Goldenzweig,
  • Y. Guan,
  • K. Gudkova,
  • C. Hadjivasiliou,
  • T. Hara,
  • O. Hartbrich,
  • K. Hayasaka,
  • H. Hayashii,
  • M. T. Hedges,
  • M. Hernandez Villanueva,
  • W.-S. Hou,
  • C.-L. Hsu,
  • K. Huang,
  • T. Iijima,
  • K. Inami,
  • G. Inguglia,
  • A. Ishikawa,
  • R. Itoh,
  • M. Iwasaki,
  • Y. Iwasaki,
  • W. W. Jacobs,
  • I. Jaegle,
  • E.-J. Jang,
  • H. B. Jeon,
  • S. Jia,
  • Y. Jin,
  • C. W. Joo,
  • K. K. Joo,
  • K. H. Kang,
  • G. Karyan,
  • T. Kawasaki,
  • C. Kiesling,
  • D. Y. Kim,
  • K.-H. Kim,
  • S. H. Kim,
  • Y.-K. Kim,
  • K. Kinoshita,
  • P. Kodyš,
  • T. Konno,
  • S. Korpar,
  • D. Kotchetkov,
  • P. Križan,
  • R. Kroeger,
  • P. Krokovny,
  • T. Kuhr,
  • M. Kumar,
  • K. Kumara,
  • K. Lalwani,
  • I. S. Lee,
  • S. C. Lee,
  • C. H. Li,
  • J. Li,
  • L. K. Li,
  • Y. B. Li,
  • L. Li Gioi,
  • J. Libby,
  • K. Lieret,
  • Z. Liptak,
  • D. Liventsev,
  • T. Luo,
  • J. MacNaughton,
  • C. MacQueen,
  • M. Masuda,
  • T. Matsuda,
  • D. Matvienko,
  • M. Merola,
  • F. Metzner,
  • K. Miyabayashi,
  • R. Mizuk,
  • G. B. Mohanty,
  • S. Mohanty,
  • T. Mori,
  • H.-G. Moser,
  • M. Mrvar,
  • R. Mussa,
  • M. Nakao,
  • Z. Natkaniec,
  • A. Natochii,
  • L. Nayak,
  • M. Nayak,
  • M. Niiyama,
  • N. K. Nisar,
  • S. Nishida,
  • S. Ogawa,
  • H. Ono,
  • Y. Onuki,
  • P. Oskin,
  • P. Pakhlov,
  • G. Pakhlova,
  • S. Pardi,
  • C. W. Park,
  • H. Park,
  • S. Patra,
  • S. Paul,
  • T. K. Pedlar,
  • R. Pestotnik,
  • L. E. Piilonen,
  • T. Podobnik,
  • V. Popov,
  • E. Prencipe,
  • M. T. Prim,
  • M. Ritter,
  • M. Röhrken,
  • A. Rostomyan,
  • N. Rout,
  • G. Russo,
  • Y. Sakai,
  • S. Sandilya,
  • A. Sangal,
  • L. Santelj,
  • T. Sanuki,
  • V. Savinov,
  • G. Schnell,
  • J. Schueler,
  • C. Schwanda,
  • Y. Seino,
  • K. Senyo,
  • M. E. Sevior,
  • M. Shapkin,
  • C. Sharma,
  • C. P. Shen,
  • J.-G. Shiu,
  • A. Sokolov,
  • E. Solovieva,
  • S. Stanič,
  • M. Starič,
  • Z. S. Stottler,
  • J. F. Strube,
  • M. Sumihama,
  • K. Sumisawa,
  • T. Sumiyoshi,
  • W. Sutcliffe,
  • M. Takizawa,
  • K. Tanida,
  • F. Tenchini,
  • M. Uchida,
  • T. Uglov,
  • Y. Unno,
  • S. Uno,
  • P. Urquijo,
  • S. E. Vahsen,
  • R. Van Tonder,
  • G. Varner,
  • K. E. Varvell,
  • A. Vinokurova,
  • V. Vorobyev,
  • E. Waheed,
  • C. H. Wang,
  • E. Wang,
  • M.-Z. Wang,
  • P. Wang,
  • M. Watanabe,
  • S. Watanuki,
  • S. Wehle,
  • E. Won,
  • X. Xu,
  • B. D. Yabsley,
  • W. Yan,
  • S. B. Yang,
  • H. Ye,
  • J. Yelton,
  • J. H. Yin,
  • Y. Yusa,
  • Z. P. Zhang,
  • V. Zhilich,
  • V. Zhukova,
  • V. Zhulanov

DOI
https://doi.org/10.1007/JHEP04(2021)191
Journal volume & issue
Vol. 2021, no. 4
pp. 1 – 19

Abstract

Read online

Abstract We present a search for the dark photon A′ in the B 0 → A′A′ decays, where A′ subsequently decays to e + e − , μ + μ − , and π + π − . The search is performed by analyzing 772 × 106 B B ¯ $$ B\overline{B} $$ 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/c 2 ≤ m A′ ≤ 2.62 GeV/c 2, and we set upper limits of the branching fraction of B 0 → A′A′ at the 90% confidence level. The products of branching fractions, ℬ B 0 → A ′ A ′ × ℬ A ′ → e + e − 2 $$ \mathrm{\mathcal{B}}\left({B}^0\to A^{\prime }A^{\prime}\right)\times \mathrm{\mathcal{B}}{\left(A\prime \to {e}^{+}{e}^{-}\right)}^2 $$ and ℬ B 0 → A ′ A ′ × ℬ A ′ → μ + μ − 2 $$ \mathrm{\mathcal{B}}\left({B}^0\to A^{\prime }A^{\prime}\right)\times \mathrm{\mathcal{B}}{\left(A\prime \to {\mu}^{+}{\mu}^{-}\right)}^2 $$ , 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 0 → A ′ A ′ $$ \mathrm{\mathcal{B}}\left({B}^0\to A^{\prime }A^{\prime}\right) $$ are of the order of 10 −8–10 −5. From the upper limits of ℬ B 0 → A ′ A ′ $$ \mathrm{\mathcal{B}}\left({B}^0\to A^{\prime }A^{\prime}\right) $$ , 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 m h ′ ≃ m B 0 $$ {m}_{h\prime}\simeq {m}_{B^0} $$ ± 40 MeV/c 2 and 10 −1–1 at m h ′ ≃ m B 0 $$ {m}_{h\prime}\simeq {m}_{B^0} $$ ± 3 GeV/c 2.

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