Measurements of isospin asymmetry and difference of direct $CP$ asymmetries in inclusive $B\to X_s\gamma$ decays

Journal Article · Wed Feb 20 00:00:00 EST 2019 · Physical Review. D.

DOI:https://doi.org/10.1103/PhysRevD.99.032012· OSTI ID:1495246

Watanuki, S.; Ishikawa, A.; Adachi, I.; Aihara, H.; Al Said, S.; Asner, D. M.; Aushev, T.; Ayad, R.; Babu, V.; Badhrees, I.; Bakich, A. M.; Bansal, V.; Behera, P.; Beleño, C.; Berger, M.; Bhardwaj, V.; Bhuyan, B.; Bilka, T.; Biswal, J.; Bobrov, A. ; Bonvicini, G.; Bozek, A.; Bračko, M.; Browder, T. E.; Cao, L.; Červenkov, D.; Chang, P.; Cheon, B. G.; Chilikin, K.; Cho, K.; Choi, Y.; Choudhury, S.; Cinabro, D.; Cunliffe, S.; Di Carlo, S.; Dingfelder, J.; Dong, T. V.; Eidelman, S.; Epifanov, D.; Fast, J. E.; Ferber, T.; Frey, A.; Fulsom, B. G.; Gaur, V.; Gabyshev, N.; Garmash, A.; Gelb, M.; Giri, A.; Goldenzweig, P.; Guan, Y.; Guido, E.; Haba, J.; Hayasaka, K.; Hayashii, H.; Hou, W. -S.; Iijima, T.; Inami, K.; Inguglia, G.; Itoh, R.; Iwasaki, M.; Iwasaki, Y.; Jacobs, W. W.; Jaegle, I.; Jeon, H. B.; Jia, S.; Jin, Y.; Joo, K. K.; Julius, T.; Karyan, G.; Kawasaki, T.; Kiesling, C.; Kim, D. Y.; Kim, J. B.; Kim, S. H.; Kinoshita, K.; Kodyš, P.; Korpar, S.; Kotchetkov, D.; Križan, P.; Kroeger, R.; Krokovny, P.; Kuhr, T.; Kumar, R.; Kuzmin, A.; Kwon, Y. -J.; Lee, I. S.; Lee, S. C.; Li, L. K.; Li, Y. B.; Li Gioi, L.; Libby, J.; Liventsev, D.; Lubej, M.; Luo, T.; Masuda, M.; Matsuda, T.; Merola, M.; Miyabayashi, K.; Miyata, H.; Mizuk, R.; Mohanty, G. B.; Mori, T.; Nakao, M.; Nanut, T.; Nath, K. J.; Niiyama, M.; Nishida, S.; Nishimura, K.; Ogawa, K.; Ogawa, S.; Okuno, S.; Ono, H.; Ostrowicz, W.; Pakhlov, P.; Pakhlova, G.; Pal, B.; Park, H.; Paul, S.; Pedlar, T. K.; Pestotnik, R.; Piilonen, L. E.; Prencipe, E.; Ritter, M.; Rostomyan, A.; Russo, G.; Sakai, Y.; Sandilya, S.; Santelj, L.; Savinov, V.; Schneider, O.; Schnell, G.; Schueler, J.; Schwanda, C.; Schwartz, A. J.; Seino, Y.; Senyo, K.; Seon, O.; Shebalin, V.; Shibata, T. -A.; Shiu, J. -G.; Shwartz, B.; Sokolov, A.; Solovieva, E.; Stanič, S.; Starič, M.; Sumiyoshi, T.; Sutcliffe, W.; Takizawa, M.; Tanida, K.; Taniguchi, N.; Tenchini, F.; Uchida, M.; Uglov, T.; Unno, Y.; Uno, S.; Vahsen, S. E.; Van Hulse, C.; Van Tonder, R.; Varner, G.; Varvell, K. E.; Vossen, A.; Wang, B.; Wang, C. H.; Wang, M. -Z.; Wang, P.; Watanabe, M.; Widmann, E.; Won, E.; Ye, H.; Yin, J. H.; Yusa, Y.; Zakharov, S.; Zhang, Z. P.; Zhilich, V.; Zhukova, V.; Zhulanov, V.; Zupanc, A.

We report measurements of isospin asymmetry $${\mathrm{{\Delta}}}_{0{-}}$$ and difference of direct $CP$ asymmetries $$\mathrm{{\Delta}}{A}_{CP}$$ between charged and neutral $$B{\rightarrow}{X}_{s}{\gamma}$$ decays. This analysis is based on the data sample containing $$772\times{}{10}^{6}B\overline{B}$$ pairs that was collected with the Belle detector at the KEKB energy-asymmetric $${e}^{+}{e}^{{-}}$$ collider. Using a sum-of-exclusive technique with invariant $${X}_{s}$$ mass up to $$2.8\text{ }\text{ }\mathrm{GeV}/{c}^{2}$$, we obtain $${\mathrm{{\Delta}}}_{0{-}}=[{-}0.48\pm{}1.49(\mathrm{stat})\pm{}0.97(\mathrm{syst})\pm{}1.15({f}_{+{-}}/{f}_{00})]$$% and $$\mathrm{{\Delta}}{A}_{CP}=[+3.69\pm{}2.65(\mathrm{stat})\pm{}0.76(\mathrm{syst})]$$%, where the last uncertainty for $${\mathrm{{\Delta}}}_{0{-}}$$ is due to the uncertainty on the production ratio of $${B}^{+}{B}^{{-}}$$ to $${B}^{0}{\overline{B}}^{0}$$ in $$\mathrm{{\Upsilon}}(4S)$$ decays. The measured value of $${\mathrm{{\Delta}}}_{0{-}}$$ is consistent with zero, allowing us to constrain the resolved photon contribution in the $$B{\rightarrow}{X}_{s}{\gamma}$$, and improve the branching fraction prediction. The result for $$\mathrm{{\Delta}}{A}_{CP}$$ is consistent with the prediction of the SM. We also measure the direct $CP$ asymmetries for charged and neutral $$B{\rightarrow}{X}_{s}{\gamma}$$ decays. All the measurements are the most precise to date.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States); Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Univ. of Hawaii, Honolulu, HI (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP); National Science Foundation (NSF)
• Contributing Organization: The Belle Collaboration
• Grant/Contract Number: SC0012704; SC0009973; SC0010504
• OSTI ID: 1495246
• Alternate ID(s): OSTI ID: 1501588; OSTI ID: 1593808
• Report Number(s): BNL-211368-2019-JAAM; arXiv:1807.04236v4; PRVDAQ; 032012
• Journal Information: Physical Review. D., Journal Name: Physical Review. D. Vol. 99 Journal Issue: 3; ISSN 2470-0010
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
flavor changing neutral currents
leptonic
semileptonic & radiative decays
particle decays
particle interactions
rare decays
bottom quark
photons
strange quark
CP symmetry
CP violation