First Measurement of the B^{+}→π^{+}π^{0}π^{0} Branching Fraction and CP Asymmetry

• Published in: Physical review letters Vol. 130; no. 18; p. 181804
• Main Authors: Lai, Y-T, Adachi, I, Aihara, H, Al Said, S, Asner, D M, Atmacan, H, Aulchenko, V, Aushev, T, Ayad, R, Babu, V, Bahinipati, S, Behera, P, Belous, K, Bennett, J, Bessner, M, Bhuyan, B, Bilka, T, Bobrov, A, Borah, J, Bozek, A, Bračko, M, Branchini, P, Browder, T E, Budano, A, Campajola, M, Červenkov, D, Chang, M-C, Chang, P, Chekelian, V, Chen, A, Cheon, B G, Chilikin, K, Cho, H E, Cho, K, Cho, S-J, Choi, S-K, Choi, Y, Cinabro, D, Cunliffe, S, Czank, T, Das, S, De Nardo, G, De Pietro, G, Dhamija, R, Di Capua, F, Dingfelder, J, Doležal, Z, Dong, T V, Ferber, T, Fulsom, B G, Garg, R, Gaur, V, Gabyshev, N, Giri, A, Goldenzweig, P, Graziani, E, Gu, T, Guan, Y, Gudkova, K, Hadjivasiliou, C, Halder, S, Hartbrich, O, Hayasaka, K, Hayashii, H, Higuchi, T, Hou, W-S, Hsu, C-L, Iijima, T, Inami, K, Ishikawa, A, Itoh, R, Iwasaki, M, Iwasaki, Y, Jacobs, W W, Jang, E-J, Jia, S, Jin, Y, Kaliyar, A B, Kang, K H, Kim, C H, Kim, D Y, Kim, K-H, Kim, Y-K, Kinoshita, K, Kodyš, P, Konno, T, Korobov, A, Korpar, S, Kovalenko, E, Križan, P, Krokovny, P, Kumar, M, Kumar, R, Kumara, K, Kuzmin, A, Kwon, Y-J, Lam, T, Lange, J S, Laurenza, M, Lee, S C
• Format: Journal Article
• Language: English
• Published: United States 05-05-2023
• ISSN: 1079-7114
• DOI: 10.1103/PhysRevLett.130.181804

We study B^{+}→π^{+}π^{0}π^{0} using 711  fb^{-1} of data collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We measure an inclusive branching fraction of (19.0±1.5±1.4)×10^{-6} and an inclusive CP asymmetry of (9.2±6.8±0.7)%, where the first uncertainties are statistical and the second are systematic, and a B^{+}→ρ(770)^{+}π^{0} branching fraction of (11.2±1.1±0.9_{-1.6}^{+0.8})×10^{-6}, where the third uncertainty is due to possible interference with B^{+}→ρ(1450)^{+}π^{0}. We present the first observation of a structure around 1  GeV/c^{2} in the π^{0}π^{0} mass spectrum, with a significance of 6.4σ, and measure a branching fraction to be (6.9±0.9±0.6)×10^{-6}. We also report a measurement of local CP asymmetry in this structure.