Measurement of time-dependent $CP$ violation in $B^0 \to K^0_S π^0 π^0$ decays
Creators: name: Belle Collaboration
name: Yusa, Y.
name: Aihara, H.
name: Said, S. Al
name: Asner, D. M.
name: Atmacan, H.
name: Aulchenko, V.
name: Aushev, T.
name: Ayad, R.
name: Babu, V.
name: Badhrees, I.
name: Bahinipati, S.
name: Bakich, A. M.
name: Bansal, V.
name: Behera, P.
name: Bhardwaj, V.
name: Bhuyan, B.
name: Biswal, J.
name: Bozek, A.
name: Bračko, M.
name: Browder, T. E.
name: Cao, L.
name: Červenkov, D.
name: Chekelian, V.
name: Chen, A.
name: Cheon, B. G.
name: Chilikin, K.
name: Choi, S. -K.
name: Choi, Y.
name: Cinabro, D.
name: Cunliffe, S.
name: Dash, N.
name: Di Carlo, S.
name: Dong, T. V.
name: Drásal, Z.
name: Eidelman, S.
name: Epifanov, D.
name: Fast, J. E.
name: Fulsom, B. G.
name: Garg, R.
name: Gaur, V.
name: Giri, A.
name: Goldenzweig, P.
name: Golob, B.
name: Guan, Y.
name: Haba, J.
name: Hayasaka, K.
name: Hayashii, H.
name: Hirose, S.
name: Inami, K.
name: Inguglia, G.
name: Ishikawa, A.
name: Iwasaki, M.
name: Iwasaki, Y.
name: Jacobs, W. W.
name: Jia, S.
name: Jin, Y.
name: Joo, K. K.
name: Kang, K. H.
name: Kawasaki, T.
name: Kim, D. Y.
name: Kim, J. B.
name: Kim, K. T.
name: Kim, S. H.
name: Kinoshita, K.
name: Kodyš, P.
name: Korpar, S.
name: Kotchetkov, D.
name: Križan, P.
name: Kroeger, R.
name: Kuhr, T.
name: Kumar, R.
name: Kwon, Y. -J.
name: Lange, J. S.
name: Lee, I. S.
name: Lee, S. C.
name: Li, L. K.
name: Li, Y. B.
name: Gioi, L. Li
name: Libby, J.
name: Liventsev, D.
name: Lubej, M.
name: Luo, T.
name: Masuda, M.
name: Matsuda, T.
name: Merola, M.
name: Miyabayashi, K.
name: Miyata, H.
name: Mizuk, R.
name: Mohanty, G. B.
name: Moon, H. K.
name: Nakano, E.
name: Nanut, T.
name: Nath, K. J.
name: Natkaniec, Z.
name: Nisar, N. K.
name: Nishida, S.
name: Nishimura, K.
name: Ogawa, K.
name: Ogawa, S.
name: Ono, H.
name: Pakhlova, G.
name: Pal, B.
name: Pardi, S.
name: Park, H.
name: Paul, S.
name: Pedlar, T. K.
name: Pestotnik, R.
name: Piilonen, L. E.
name: Popov, V.
name: Prencipe, E.
name: Rostomyan, A.
name: Russo, G.
name: Sakai, Y.
name: Sandilya, S.
name: Sanuki, T.
name: Savinov, V.
name: Schneider, O.
name: Schnell, G.
name: Schwanda, C.
name: Schwartz, A. J.
name: Seino, Y.
name: Senyo, K.
name: Seon, O.
name: Sevior, M. E.
name: Shen, C. P.
name: Shibata, T. -A.
name: Shiu, J. -G.
name: Starič, M.
name: Sumihama, M.
name: Sumiyoshi, T.
name: Takizawa, M.
name: Tamponi, U.
name: Tanida, K.
name: Tenchini, F.
name: Uchida, M.
name: Uglov, T.
name: Unno, Y.
name: Uno, S.
name: Ushiroda, Y.
name: Usov, Y.
name: Van Hulse, C.
name: Van Tonder, R.
name: Varner, G.
name: Varvell, K. E.
name: Vorobyev, V.
name: Vossen, A.
name: Waheed, E.
name: Wang, B.
name: Wang, C. H.
name: Wang, M. -Z.
name: Wang, P.
name: Won, E.
name: Ye, H.
name: Yin, J. H.
name: Zhang, Z. P.
name: Zhilich, V.
name: Zhulanov, V.
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report a measurement of time-dependent $CP$ violation in $B^0 \to K^0_S π^0 π^0$ decays using a data sample of $772 \times 10^6$ $B\bar{B}$ pairs collected by the Belle experiment runnin g at the $Υ(4S)$ resonance at the KEKB $e^+ e^-$ collider. This decay proceeds mainly via a $b\to sd\bar{d}$ "penguin" amplitude. The results are $\sin 2ϕ^{\rm eff}_1 = 0.92^{+0.27}_{-0.31}~$ (stat.) $\pm 0.11$ (syst.) and $\mathcal{A} = 0.28 \pm 0.21$ (stat.) $\pm 0.04$ (syst.), which are the most precise measurements of $CP$ violati on in this decay mode to date. The value for the $CP$-violating parameter $\sin 2ϕ^{\rm eff}_1$ is consistent with that obtained using decay modes proceeding via a $b\to c\bar{c}s$ "tree" amplitude.
description: 7 pages, 3 figures, submitted to PRD(RC)