Measurement of branching fractions and search for CP violation in D0 → π+π−η, D0 → K+K−η, and D0 → ϕη at Belle

• Published in: The journal of high energy physics 2021-09, Vol.2021 (9), Article 75
• Main Authors: Li, L. K., Schwartz, A. J., Adachi, I., Aihara, H., Aulchenko, V., Ayad, R., Babu, V., Bahinipati, S., Biswal, J., Bobrov, A., Bonvicini, G., Bračko, M., Browder, T. E., Budano, A., Campajola, M., Chang, P., Chen, Y. Q., Cheon, B. G., Cho, H. E., Cho, S.-J., Choudhury, S., Cinabro, D., Dash, N., Dhamija, R., Di Capua, F., Eidelman, S., Epifanov, D., Ferber, T., Giri, A., Goldenzweig, P., Golob, B., Graziani, E., Gu, T., Hadjivasiliou, C., Hou, W.-S., Ishikawa, A., Iwasaki, Y., Jacobs, W. W., Jin, Y., Joo, K. K., Kim, C. H., Kim, K.-H., Kim, S. H., Kim, Y.-K., Konno, T., Korpar, S., Kovalenko, E., Križan, P., Kroeger, R., Kumara, K., Lalwani, K., Lee, S. C., Li, C. H., Gioi, L. Li, Libby, J., Lieret, K., Liventsev, D., Merola, M., Metzner, F., Mohanty, G. B., Mori, T., Nakao, M., Natkaniec, Z., Natochii, A., Nayak, L., Niiyama, M., Pakhlov, P., Pakhlova, G., Passeri, A., Paul, S., Popov, V., Prencipe, E., Prim, M. T., Sahoo, D., Sakai, Y., Sandilya, S., Sangal, A., Santelj, L., Sanuki, T., Savinov, V., Schwanda, C., Seino, Y., Senyo, K., Shen, C. P., Starič, M., Stottler, Z. S., Sumiyoshi, T., Tenchini, F., Uchida, M., Uglov, T., Unno, Y., Uno, K., Uno, S., Van Tonder, R., Vinokurova, A., Wang, X. L., Yan, W. B., Yelton, J., Yin, J. H., Zhang, Z. P.
• Format: Article
• Language: English
• Subjects: Asymmetry; Classical and Quantum Gravitation; CP violation; Decay; Elementary Particles; High energy physics; Laboratories; Nuclear physics; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Experimental Physics; Relativity Theory; Science; String Theory; Uncertainty
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP09(2021)075

A bstract 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 , where the third uncertainty ( 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 % . 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.