Li, Y.Li, Y. B.Shen, C. P.Adachi, I.Aihara, H.Asner, D. M.Atmacan, H.Aulchenko, V.Ayad, R.Babu, V.Badhrees, I.Bakich, A. M.Behera, P.Bilka, T.Biswal, J.Bobrov, A.Bonvicini, G.Bozek, A.Bracko, M.Browder, T. E.Campajola, M.Cao, L.Cervenkov, D.Chang, P.Chen, A.Cheon, B. G.Chilikin, K.Cho, H. E.Cho, K.Choi, S. -K.Choi, Y.Cinabro, D.Cunliffe, S.De Nardo, G.Di Capua, F.Di Carlo, S.Dolezal, Z.Dong, T. V.Eidelman, S.Fast, J. E.Ferber, T.Ferlewicz, D.Fulsom, B. G.Garg, R.Gaur, V.Gabyshev, N.Garmash, A.Giri, A.Goldenzweig, P.Golob, B.Grube, B.Hara, T.Hayasaka, K.Hayashii, H.Hou, W. -S.Hsu, C. -L.Iijima, T.Inami, K.Inguglia, G.Ishikawa, A.Itoh, R.Iwasaki, M.Iwasaki, Y.Jacobs, W. W.Jia, S.Jin, Y.Joo, K. K.Kang, K. H.Karyan, G.Kichimi, H.Kim, C. H.Kim, D. Y.Kim, S. H.Kinoshita, K.Kodys, P.Korpar, S.Kroeger, R.Krokovny, P.Kuhr, T.Kulasiri, R.Kuzmin, A.Kwon, Y. -J.Lalwani, K.Lange, J. S.Lee, I. S.Lee, S. C.Lewis, P.Li, C. H.Li, L. K.Gioi, L. LiLibby, J.Lieret, K.Liventsev, D.MacQueen, C.Masuda, M.Matsuda, T.Matvienko, D.Merola, M.Miyata, H.Mizuk, R.Mussa, R.Nakao, M.Nath, K. J.Nayak, M.Niiyama, M.Nisar, N. K.Nishida, S.Nishimura, K.Ogawa, S.Ono, H.Onuki, Y.Oskin, P.Pakhlov, P.Pakhlova, G.Pang, T.Pardi, S.Park, H.Park, S. -H.Patra, S.Paul, S.Pedlar, T. K.Pestotnik, R.Piilonen, L. E.Podobnik, T.Popov, V.Prencipe, E.Prim, M. T.Roehrken, M.Rostomyan, A.Rout, N.Russo, G.Sahoo, D.Sakai, Y.Sandilya, S.Santelj, L.Savinov, V.Schneider, O.Schnell, G.Schwanda, C.Seino, Y.Senyo, K.Sevior, M. E.Shiu, J. -G.Shwartz, B.Sokolov, A.Solovieva, E.Stanic, S.Staric, M.Stottler, Z. S.Sumihama, M.Sumiyoshi, T.Sutcliffe, W.Takizawa, M.Tanida, K.Tenchini, F.Trabelsi, K.Uchida, M.Uglov, T.Unno, Y.Uno, S.Van Tonder, R.Varner, G.Vinokurova, A.Wang, C. H.Wang, M. -Z.Wang, X. L.Watanabe, M.Won, E.Yang, S. B.Ye, H.Yelton, J.Yin, J. H.Yuan, C. Z.Zhang, Z. P.Zhilich, V.Zhukova, V.Zhulanov, V.2021-05-222021-05-222021-05-222021-04-2010.1007/JHEP04(2021)191https://infoscience.epfl.ch/handle/20.500.14299/178348WOS:000644192500001We present a search for the dark photon A in the B-0 -> A ' A ' decays, where A ' subsequently decays to e(+)e(-), mu (+)mu (-), and pi (+)pi (-). The search is performed by analyzing 772 x 10(6)BB<overbar></mml:mover> events collected by the Belle detector at the KEKB e(+)e(-) energy-asymmetric collider at the Upsilon (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<mml:mfenced close=")" open="(">B0 -> A ' A '</mml:mfenced>xB<mml:mfenced close=")" open="(">A ' -> e+e-</mml:mfenced>2 and B<mml:mfenced close=")" open="(">B0 -> A ' A '</mml:mfenced>xB<mml:mfenced close=")" open="(">A ' -> mu+mu-</mml:mfenced>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<mml:mfenced close=")" open="(">B0 -> A ' A '</mml:mfenced> are of the order of 10(-8)-10(-5). From the upper limits of B<mml:mfenced close=")" open="(">B0 -> A ' A '</mml:mfenced>, 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 ' similar or equal to mB0 +/- 40 MeV/c(2) and 10(-1)-1 at mh ' <mml:mo>similar or equal to mB0 +/- 3 GeV/c(2).<fig id="Figa" position="anchor"><graphic position="anchor" specific-use="HTML" mime-subtype="JPEG" xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="MediaObjects/13130_2021_15453_Figa_HTML.jpg" id="MO1"></graphicPhysics, Particles & FieldsPhysicsb physicsbeyond standard modele plus -e- experimentsrare decayidentificationtext::journal::journal article::research article