Measurement of time-dependent $CP$ violation parameters in $B^{0} \to K_{S}^{0} π^{0} γ$ decays at Belle and Belle II

Bibliographic Details
Title: Measurement of time-dependent $CP$ violation parameters in $B^{0} \to K_{S}^{0} π^{0} γ$ decays at Belle and Belle II
Authors: Belle, Collaborations, Belle II, Abumusabh, M., Adachi, I., Aggarwal, A., Ahn, Y., Aihara, H., Akdag, M., Akopov, N., Alghamdi, S., Alhakami, M., Althubiti, N., Amos, K., Angelsmark, M., Ky, N. Anh, Antonioli, C., Arai, K., Atmacan, H., Aushev, T., Aushev, V., Ayad, R., Babu, V., Bae, H., Baghel, N. K., Bahinipati, S., Bambade, P., Banerjee, Sw., Bansal, S., Barrett, M., Bartl, M., Baudot, J., Beaubien, A., Becherer, F., Becker, J., Benfratello, G. F., Bennett, J. V., Bernlochner, F. U., Bertacchi, V., Bertemes, M., Bertholet, E., Bessner, M., Bettarini, S., Bhardwaj, V., Bhuyan, B., Bianchi, F., Bilka, T., Biswas, D., Bobrov, A., Bodrov, D., Bondar, A., Bonvicini, G., Borah, J., Boschetti, A., Bozek, A., Bračko, M., Branchini, P., Brenny, N., Briere, R. A., Browder, T. E., Budano, A., Bussino, S., Callet, F., Campagna, Q., Campajola, M., Cao, L., Carminati, M., Casarosa, G., Cecchi, C., Cheema, P., Chen, L., Cheon, B. G., Cheshta, C., Chetri, H., Chilikin, K., Chirapatpimol, K., Cho, H. -E., Cho, K., Cho, S. -J., Choi, S. -K., Choudhury, S., Chutia, S., Cochran, J., Colorado-Caicedo, J. A., Consigny, I., Corona, L., Ledesma, H. Crotte, Cuccuini, S., Cui, J. X., Das, S., De La Cruz-Burelo, E., De La Motte, S. A., de Marino, G., De Nardo, G., De Pietro, G., de Sangro, R., Destefanis, M., Dey, S., Dhayal, R., Di Canto, A., Dingfelder, J., Doležal, Z., Dong, X., Dorigo, M., Dujany, G., Ecker, P., Epifanov, D., Eppelt, J., Farkas, R., Feichtinger, P., Ferber, T., Fillinger, T., Finck, C., Finocchiaro, G., Forti, F., Frey, A., Fulsom, B. G., Gabrielli, A., Gagneja, P., Ganiev, E., Garg, R., Gaudino, G., Gaur, V., Gautam, V., Gaz, A., Gellrich, A., Ghevondyan, G., Ghosh, D., Ghumaryan, H., Giordano, R., Giri, A., Gironell, P. Gironella, Gobbo, B., Godang, R., Gogota, O., Gradl, W., Graziani, E., Greenwald, D., Guan, Y., Gudkova, K., Haide, I., Han, Y., Hayasaka, K., Hayashii, H., Hazra, S., Hearty, C., Hedges, M. T., Heidelbach, A., Heine, G., de la Cruz, I. Heredia, Higuchi, T., Hoek, M., Hohmann, M., Hoppe, R., Horak, P., Hou, X. T., Hsu, C. -L., Humair, T., Iijima, T., Inami, K., Ipsita, N., Ishikawa, A., Itoh, R., Iwasaki, M., Jackson, P., Jacobi, D., Jacobs, W. W., Jang, E. -J., Ji, Q. P., Jia, S., Jin, Y., Johnson, A., Joo, K. K., Kang, K. H., Karyan, G., Kawasaki, T., Keil, F., Kiesling, C., Kim, C., Kim, D. Y., Kim, H., Kim, J. -Y., Kim, K. -H., Kinoshita, K., Kodyš, P., Koga, T., Kohani, S., Korobov, A., Korpar, S., Kovalenko, E., Kowalewski, R., Križan, P., Krokovny, P., Kuhr, T., Kulii, Y., Kumar, R., Kumara, K., Kunigo, T., Kurokawa, S., Kuzmin, A., Kwon, Y. -J., Lacaprara, S., Lai, Y. -T., Lam, T., Lange, J. S., Lau, T. S., Leboucher, R., Lee, H., Lee, M. J., Leo, P., Lewis, P. M., Li, C., Li, L. K., Li, Q. M., Li, S. X., Li, W. Z., Li, Y., Li, Y. B., Liao, Y. P., Libby, J., Lin, J., Lin, S., Liptak, Z., Lisovskyi, V., Liu, C., Liu, G., Liu, M. H., Liu, Q. Y., Liu, Z. Q., Liventsev, D., Longo, S., Lozar, A., Lueck, T., Ma, J. L., Ma, Y., Maggiora, M., Maharana, S. P., Maiti, R., Mancinelli, G., Manfredi, R., Manoni, E., Mantovano, M., Marcantonio, D., Marfoli, M., Marinas, C., Martens, A., Martinov, T., Massaccesi, L., Masuda, M., Matsuda, T., Matvienko, D., Maurya, S. K., Maushart, M., McKenna, J. A., Gruberová, Z. Mediankin, Mehta, R., Meier, F., Meleshko, D., Merola, M., Miller, C., Mirra, M., Miyabayashi, K., Miyake, H., Mizuk, R., Mohanty, G. B., Moneta, S., de Carvalho, A. L. Moreira, Moser, H. -G., Mudgal, N., Muller, Th., Murakami, H., Mussa, R., Nakao, M., Nakazawa, Y., Natkaniec, Z., Natochii, A., Neu, M., Nishida, S., Nomaru, R., Ogawa, S., Okubo, R., Ono, H., Onuki, Y., Pakhlova, G., Pardi, S., Park, J., Park, K., Park, S. -H., Passeri, A., Patra, S., Pedlar, T. K., Piccolo, M., Piilonen, L. E., Podesta-Lerma, P. L. M., Podobnik, T., Polat, L., Prakash, A., Prasad, V., Praz, C., Prell, S., Prencipe, E., Prim, M. T., Privalov, S., Prudiiev, I., Purwar, H., Rados, P., Raiz, S., Ravindran, K., Rehman, J. U., Reif, M., Reiter, S., Reuter, L., Herrmann, D. Ricalde, Ripp-Baudot, I., Rizzo, G., Robertson, S. H., Roney, J. M., Rostomyan, A., Rout, N., Russo, G., Saha, S., Salutari, L., Sanders, D. A., Sandilya, S., Santelj, L., Santos, C., Savinov, V., Scavino, B., Schmitt, C., Schmitz, J., Schnell, G., Schoenning, K., Schwanda, C., Seino, Y., Senyo, K., Serrano, J., Sfienti, C., Shan, W., Shen, C. P., Shi, X. D., Shillington, T., Shimasaki, T., Shiu, J. -G., Shtol, D., Shwartz, B., Sibidanov, A., Simon, F., Singh, J. B., Skorupa, J., Soffer, A., Sokolov, A., Solovieva, E., Spataro, S., Špenko, K., Spruck, B., Starič, M., Stavroulakis, P., Stefkova, S., Stroili, R., Sumihama, M., Takahashi, M., Takizawa, M., Tamponi, U., Tanida, K., Testa, F., Thaller, A., Thanh, D. V., Manh, T. Tien, Tittel, O., Tiwary, R., Torassa, E., Trabelsi, K., Trantou, F. F., Tsaklidis, I., Uchida, M., Ueda, I., Uglov, T., Unger, K., Unno, Y., Uno, K., Uno, S., Ushiroda, Y., van Tonder, R., Varvell, K. E., Veronesi, M., Vinokurova, A., Vismaya, V. S., Vitale, L., Vobbilisetti, V., Volpe, R., Wakai, M., Wallner, S., Wang, M. -Z., Warburton, A., Watanabe, M., Watanuki, S., Wessel, C., Xu, X. P., Yabsley, B. D., Yamada, S., Yan, W., Yan, W. P., Yelton, J., Yi, K., Yin, J. H., Yoshihara, K., Yuan, C. Z., Yuan, J., Yuan, L., Yusa, Y., Zani, L., Zeng, F., Zeyrek, M., Zhang, B., Zhao, X., Zhilich, V., Zhou, Q. D., Zhou, X. Y., Zhu, L., Žlebčík, R.
Source: JHEP 09 (2026) 216
Publication Year: 2026
Collection: High Energy Physics - Experiment
Subject Terms: High Energy Physics - Experiment
Description: We perform a measurement of time-dependent $CP$ violation parameters in $B^{0} \to K_{S}^{0} π^{0} γ$ decays using a dataset of approximately $772 \times 10^6$ and $521 \times 10^6$ $Υ(4S)$ decays collected by the Belle and Belle II experiments, respectively. The measured parameters for the combined dataset in the $K^{*0}(892)$ dominated region ($M_{K_{S}^{0} π^{0}} \in [0.8,1.0] \mathrm{GeV}/c^2$) are $S = 0.09 \pm 0.16 \pm 0.02$ and $C = -0.09 \pm 0.08 \pm 0.04$. For the non-$K^{*0}(892)$ region ($M_{K_{S}^{0} π^{0}} \in [1.0,1.8] \mathrm{GeV}/c^2$), the corresponding values are $S = -0.32 \pm 0.33 \pm 0.09$ and $C = -0.07 \pm 0.17 \pm 0.08$. The first quoted uncertainties are statistical, while the second ones are systematic. These results are consistent with Standard Model predictions and more precise than previous measurements.
Document Type: Working Paper
DOI: 10.48550/arXiv.2606.04496
Access URL: https://arxiv.org/abs/2606.04496
Accession Number: edsarx.2606.04496
Database: arXiv
Description
DOI:10.48550/arXiv.2606.04496