Measurement of branching fractions and search for CP violation in D 0 → π + π − η, D 0 → K + K − η, and D 0 → ϕη at Belle

oleh: The Belle collaboration, L. K. Li, A. J. Schwartz, K. Kinoshita, I. Adachi, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, V. Aulchenko, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, P. Behera, J. Bennett, M. Bessner, T. Bilka, J. Biswal, A. Bobrov, G. Bonvicini, A. Bozek, M. Bračko, P. Branchini, T. E. Browder, A. Budano, M. Campajola, D. Červenkov, M.-C. Chang, P. Chang, V. Chekelian, A. Chen, Y. Q. 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, G. De Pietro, R. Dhamija, F. Di Capua, Z. Doležal, T. V. Dong, S. Eidelman, D. Epifanov, T. Ferber, B. G. Fulsom, R. Garg, V. Gaur, A. Giri, P. Goldenzweig, B. Golob, E. Graziani, T. Gu, Y. Guan, C. Hadjivasiliou, S. Halder, K. Hayasaka, W.-S. Hou, K. Inami, A. Ishikawa, M. Iwasaki, Y. Iwasaki, W. W. Jacobs, E.-J. Jang, S. Jia, Y. Jin, K. K. Joo, K. H. Kang, G. Karyan, C. Kiesling, C. H. Kim, D. Y. Kim, K.-H. Kim, S. H. Kim, Y.-K. Kim, P. Kodyš, T. Konno, A. Korobov, S. Korpar, E. Kovalenko, P. Križan, R. Kroeger, P. Krokovny, T. Kuhr, M. Kumar, K. Kumara, A. Kuzmin, Y.-J. Kwon, K. Lalwani, M. Laurenza, S. C. Lee, C. H. Li, L. Li Gioi, J. Libby, K. Lieret, D. Liventsev, M. Masuda, D. Matvienko, M. Merola, F. Metzner, K. Miyabayashi, R. Mizuk, G. B. Mohanty, T. Mori, M. Nakao, Z. Natkaniec, A. Natochii, L. Nayak, M. Nayak, M. Niiyama, N. K. Nisar, S. Nishida, K. Nishimura, H. Ono, P. Oskin, P. Pakhlov, G. Pakhlova, S. Pardi, S.-H. Park, A. Passeri, S. Paul, T. K. Pedlar, R. Pestotnik, L. E. Piilonen, T. Podobnik, V. Popov, E. Prencipe, M. T. Prim, N. Rout, G. Russo, D. Sahoo, Y. Sakai, S. Sandilya, A. Sangal, L. Santelj, T. Sanuki, V. Savinov, G. Schnell, C. Schwanda, Y. Seino, K. Senyo, M. Shapkin, C. Sharma, C. P. Shen, J.-G. Shiu, B. Shwartz, A. Sokolov, E. Solovieva, M. Starič, Z. S. Stottler, M. Sumihama, T. Sumiyoshi, M. Takizawa, K. Tanida, F. Tenchini, M. Uchida, T. Uglov, Y. Unno, K. Uno, S. Uno, S. E. Vahsen, R. Van Tonder, G. Varner, A. Vinokurova, E. Waheed, C. H. Wang, M.-Z. Wang, P. Wang, X. L. Wang, S. Watanuki, E. Won, B. D. Yabsley, W. B. Yan, S. B. Yang, H. Ye, J. Yelton, J. H. Yin, Y. Yusa, Z. P. Zhang, V. Zhilich, V. Zhukova

Format: Article
Diterbitkan: SpringerOpen 2021-09-01

Deskripsi

Abstract We measure the branching fractions and CP asymmetries for the singly Cabibbo-suppressed decays D 0 → π + π − η, D 0 → K + K − η, and D 0 → ϕη, using 980 fb −1 of data from the Belle experiment at the KEKB e + e − collider. We obtain B D 0 → π + π − η = 1.22 ± 0.02 stat ± 0.02 syst ± 0.03 B ref × 10 − 3 , B D 0 → K + K − η = 1.80 − 0.06 + 0.07 stat ± 0.04 syst ± 0.05 B ref × 10 − 4 , B D 0 → ϕη = 1.84 ± 0.09 stat ± 0.06 syst ± 0.05 B ref × 10 − 4 , $$ {\displaystyle \begin{array}{c}\mathcal{B}\left({D}^0\to {\pi}^{+}{\pi}^{-}\eta \right)=\left[1.22\pm 0.02\left(\mathrm{stat}\right)\pm 0.02\left(\mathrm{syst}\right)\pm 0.03\left({\mathcal{B}}_{\mathrm{ref}}\right)\right]\times {10}^{-3},\\ {}\mathcal{B}\left({D}^0\to {K}^{+}{K}^{-}\eta \right)=\left[{1.80}_{-0.06}^{+0.07}\left(\mathrm{stat}\right)\pm 0.04\left(\mathrm{syst}\right)\pm 0.05\left({\mathcal{B}}_{\mathrm{ref}}\right)\right]\times {10}^{-4},\\ {}\mathcal{B}\left({D}^0\to \phi \eta \right)=\left[1.84\pm 0.09\left(\mathrm{stat}\right)\pm 0.06\left(\mathrm{syst}\right)\pm 0.05\left({\mathcal{B}}_{\mathrm{ref}}\right)\right]\times {10}^{-4},\end{array}} $$ where the third uncertainty ( B $$ \mathcal{B} $$ ref) is from the uncertainty in the branching fraction of the reference mode D 0 → K − π + η. The color-suppressed decay D 0 → ϕη is observed for the first time, with very high significance. The results for the CP asymmetries are A CP D 0 π + π − η = 0.9 ± 1.2 stat ± 0.5 syst % , A CP D 0 → K + K − η = − 1.4 ± 3.3 stat ± 1.1 syst % , ACP D 0 → ϕη = − 1.9 ± 4.4 stat ± 0.6 syst % . $$ {\displaystyle \begin{array}{c}{A}_{CP}\left({D}^0\ {\pi}^{+}{\pi}^{-}\eta \right)=\left[0.9\pm 1.2\left(\mathrm{stat}\right)\pm 0.5\left(\mathrm{syst}\right)\right]\%,\\ {}{A}_{CP}\left({D}^0\to {K}^{+}{K}^{-}\eta \right)=\left[-1.4\pm 3.3\left(\mathrm{stat}\right)\pm 1.1\left(\mathrm{syst}\right)\right]\%,\\ {} ACP\ \left({D}^0\to \phi \eta \right)=\left[-1.9\pm 4.4\left(\mathrm{stat}\right)\pm 0.6\left(\mathrm{syst}\right)\right]\%.\end{array}} $$ The results for D 0 → π + π − η are a significant improvement over previous results. The branching fraction and A CP results for D 0 → K + K − η, and the ACP result for D 0 → ϕη, are the first such measurements. No evidence for CP violation is found in any of these decays.