Difference in direct charge-parity violation between charged and neutral B meson decays

S. W. Lin; Y. Unno; W. S. Hou; P. Chang; I. Adachi; H. Aihara; K. Akai; K. Arinstein; V. Aulchenko; T. Aushev; T. Aziz; A. M. Bakich; V. Balagura; E. Barberio; A. Bay; I. Bedny; U. Bitenc; A. Bondar; A. Bozek; M. Bračko; T. E. Browder; M. C. Chang; Y. Chao; A. Chen; K. F. Chen; W. T. Chen; B. G. Cheon; C. C. Chiang; R. Chistov; I. S. Cho; S. K. Choi; Y. Choi; Y. K. Choi; S. Cole; J. Dalseno; M. Danilov; M. Dash; A. Drutskoy; S. Eidelman; D. Epifanov; S. Fratina; M. Fujikawa; K. Furukawa; N. Gabyshev; P. Goldenzweig; B. Golob; H. Ha; J. Haba; T. Hara; K. Hayasaka; H. Hayashii; M. Hazumi; D. Heffernan; T. Hokuue; Y. Hoshi; Y. B. Hsiung; H. J. Hyun; T. Iijima; K. Ikado; K. Inami; A. Ishikawa; H. Ishino; R. Itoh; M. Iwabuchi; M. Iwasaki; Y. Iwasaki; D. H. Kah; H. Kaji; S. U. Kataoka; H. Kawai; T. Kawasaki; A. Kibayashi; H. Kichimi; E. Kikutani; H. J. Kim; S. K. Kim; Y. J. Kim; K. Kinoshita; S. Korpar; Y. Kozakai; P. Križan; P. Krokovny; R. Kumar; C. C. Kuo; A. Kuzmin; Y. J. Kwon; M. J. Lee; S. E. Lee; T. Lesiak; J. Li; Y. Liu; D. Liventsev; F. Mandl; D. Marlow; S. McOnie; T. Medvedeva; T. Mimashi; W. Mitaroff; K. Miyabayashi; H. Miyake; Y. Miyazaki; R. Mizuk; T. Mori; T. T. Nakamura; E. Nakano; M. Nakao; H. Nakazawa; S. Nishida; O. Nitoh; S. Noguchi; T. Nozaki; S. Ogawa; Y. Ogawa; T. Ohshima; S. Okuno; S. L. Olsen; H. Ozaki; G. Pakhlova; C. W. Park; H. Park; L. S. Peak; R. Pestotnik; M. Peters; L. E. Piilonen; A. Poluektov; H. Sahoo; Y. Sakai; O. Schneider; J. Schümann; A. J. Schwartz; R. Seidl; K. Senyo; M. E. Sevior; M. Shapkin; C. P. Shen; H. Shibuya; T. Shidara; S. Shinomiya; J. G. Shiu; B. Shwartz; J. B. Singh; A. Sokolov; A. Somov; S. Stanič; M. Starič; K. Sumisawa; T. Sumiyoshi; S. Suzuki; O. Tajima; F. Takasaki; N. Tamura; M. Tanaka; M. Tawada; G. N. Taylor; Y. Teramoto; I. Tikhomirov; K. Trabelsi; S. Uehara; K. Ueno; T. Uglov; S. Uno; P. Urquijo; Y. Ushiroda; Y. Usov; G. Varner; K. E. Varvell; K. Vervink; S. Villa; C. C. Wang; C. H. Wang; M. Z. Wang; Y. Watanabe; R. Wedd; J. Wicht; E. Won; B. D. Yabsley; A. Yamaguchi; Y. Yamashita; M. Yamauchi; M. Yoshida; C. Z. Yuan; Y. Yusa; C. C. Zhang; Z. P. Zhang; V. Zhilich; V. Zhulanov; A. Zupanc

doi:10.1038/nature06827

Difference in direct charge-parity violation between charged and neutral B meson decays

S. W. Lin, Y. Unno, W. S. Hou, P. Chang, I. Adachi, H. Aihara, K. Akai, K. Arinstein, V. Aulchenko, T. Aushev, T. Aziz, A. M. Bakich, V. Balagura, E. Barberio, A. Bay, I. Bedny, U. Bitenc, A. Bondar, A. Bozek, M. BračkoT. E. Browder, M. C. Chang, Y. Chao, A. Chen, K. F. Chen, W. T. Chen, B. G. Cheon, C. C. Chiang, R. Chistov, I. S. Cho, S. K. Choi, Y. Choi, Y. K. Choi, S. Cole, J. Dalseno, M. Danilov, M. Dash, A. Drutskoy, S. Eidelman, D. Epifanov, S. Fratina, M. Fujikawa, K. Furukawa, N. Gabyshev, P. Goldenzweig, B. Golob, H. Ha, J. Haba, T. Hara, K. Hayasaka, H. Hayashii, M. Hazumi, D. Heffernan, T. Hokuue, Y. Hoshi, Y. B. Hsiung, H. J. Hyun, T. Iijima, K. Ikado, K. Inami, A. Ishikawa, H. Ishino, R. Itoh, M. Iwabuchi, M. Iwasaki, Y. Iwasaki, D. H. Kah, H. Kaji, S. U. Kataoka, H. Kawai, T. Kawasaki, A. Kibayashi, H. Kichimi, E. Kikutani, H. J. Kim, S. K. Kim, Y. J. Kim, K. Kinoshita, S. Korpar, Y. Kozakai, P. Križan, P. Krokovny, R. Kumar, C. C. Kuo, A. Kuzmin, Y. J. Kwon, M. J. Lee, S. E. Lee, T. Lesiak, J. Li, Y. Liu, D. Liventsev, F. Mandl, D. Marlow, S. McOnie, T. Medvedeva, T. Mimashi, W. Mitaroff, K. Miyabayashi, H. Miyake, Y. Miyazaki, R. Mizuk, T. Mori, T. T. Nakamura, E. Nakano, M. Nakao, H. Nakazawa, S. Nishida, O. Nitoh, S. Noguchi, T. Nozaki, S. Ogawa, Y. Ogawa, T. Ohshima, S. Okuno, S. L. Olsen, H. Ozaki, G. Pakhlova, C. W. Park, H. Park, L. S. Peak, R. Pestotnik, M. Peters, L. E. Piilonen, A. Poluektov, H. Sahoo, Y. Sakai, O. Schneider, J. Schümann, A. J. Schwartz, R. Seidl, K. Senyo, M. E. Sevior, M. Shapkin, C. P. Shen, H. Shibuya, T. Shidara, S. Shinomiya, J. G. Shiu, B. Shwartz, J. B. Singh, A. Sokolov, A. Somov, S. Stanič, M. Starič, K. Sumisawa, T. Sumiyoshi, S. Suzuki, O. Tajima, F. Takasaki, N. Tamura, M. Tanaka, M. Tawada, G. N. Taylor, Y. Teramoto, I. Tikhomirov, K. Trabelsi, S. Uehara, K. Ueno, T. Uglov, S. Uno, P. Urquijo, Y. Ushiroda, Y. Usov, G. Varner, K. E. Varvell, K. Vervink, S. Villa, C. C. Wang, C. H. Wang, M. Z. Wang, Y. Watanabe, R. Wedd, J. Wicht, E. Won, B. D. Yabsley, A. Yamaguchi, Y. Yamashita, M. Yamauchi, M. Yoshida, C. Z. Yuan, Y. Yusa, C. C. Zhang, Z. P. Zhang, V. Zhilich, V. Zhulanov, A. Zupanc

Research output: Contribution to journal › Article › peer-review

142 Scopus citations

Abstract

Equal amounts of matter and antimatter are predicted to have been produced in the Big Bang, but our observable Universe is clearly matter-dominated. One of the prerequisites for understanding this elimination of antimatter is the nonconservation of charge-parity (CP) symmetry. So far, two types of CP violation have been observed in the neutral K meson (K⁰) and B meson (B⁰) systems: CP violation involving the mixing between K⁰ and its antiparticle (and likewise for B⁰ and ), and direct CP violation in the decay of each meson. The observed effects for both types of CP violation are substantially larger for the B⁰ meson system. However, they are still consistent with the standard model of particle physics, which has a unique source of CP violation that is known to be too small to account for the matter-dominated Universe. Here we report that the direct CP violation in charged B^±→K^±π⁰ decay is different from that in the neutral B⁰ counterpart. The direct CP-violating decay rate asymmetry, (that is, the difference between the number of observed B^-→K^-π⁰ event versus B ⁺→K⁺ π⁰ events, normalized to the sum of these events) is measured to be about +7%, with an uncertainty that is reduced by a factor of 1.7 from a previous measurement. However, the asymmetry for versus B⁰→K⁺π^- is at the -10% level. Although it is susceptible to strong interaction effects that need further clarification, this large deviation in direct CP violation between charged and neutral B meson decays could be an indication of new sources of CP violation - which would help to explain the dominance of matter in the Universe.

Original language	English
Pages (from-to)	332-335
Number of pages	4
Journal	Nature
Volume	452
Issue number	7185
DOIs	https://doi.org/10.1038/nature06827
State	Published - 20 Mar 2008

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10.1038/nature06827

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Lin, S. W., Unno, Y., Hou, W. S., Chang, P., Adachi, I., Aihara, H., Akai, K., Arinstein, K., Aulchenko, V., Aushev, T., Aziz, T., Bakich, A. M., Balagura, V., Barberio, E., Bay, A., Bedny, I., Bitenc, U., Bondar, A., Bozek, A., ... Zupanc, A. (2008). Difference in direct charge-parity violation between charged and neutral B meson decays. Nature, 452(7185), 332-335. https://doi.org/10.1038/nature06827

@article{623acea70f8043f98e1f6ecf548a8071,

title = "Difference in direct charge-parity violation between charged and neutral B meson decays",

abstract = "Equal amounts of matter and antimatter are predicted to have been produced in the Big Bang, but our observable Universe is clearly matter-dominated. One of the prerequisites for understanding this elimination of antimatter is the nonconservation of charge-parity (CP) symmetry. So far, two types of CP violation have been observed in the neutral K meson (K0) and B meson (B0) systems: CP violation involving the mixing between K0 and its antiparticle (and likewise for B0 and ), and direct CP violation in the decay of each meson. The observed effects for both types of CP violation are substantially larger for the B0 meson system. However, they are still consistent with the standard model of particle physics, which has a unique source of CP violation that is known to be too small to account for the matter-dominated Universe. Here we report that the direct CP violation in charged B±→K±π0 decay is different from that in the neutral B0 counterpart. The direct CP-violating decay rate asymmetry, (that is, the difference between the number of observed B-→K-π0 event versus B +→K+ π0 events, normalized to the sum of these events) is measured to be about +7%, with an uncertainty that is reduced by a factor of 1.7 from a previous measurement. However, the asymmetry for versus B0→K+π- is at the -10% level. Although it is susceptible to strong interaction effects that need further clarification, this large deviation in direct CP violation between charged and neutral B meson decays could be an indication of new sources of CP violation - which would help to explain the dominance of matter in the Universe.",

author = "Lin, {S. W.} and Y. Unno and Hou, {W. S.} and P. Chang and I. Adachi and H. Aihara and K. Akai and K. Arinstein and V. Aulchenko and T. Aushev and T. Aziz and Bakich, {A. M.} and V. Balagura and E. Barberio and A. Bay and I. Bedny and U. Bitenc and A. Bondar and A. Bozek and M. Bra{\v c}ko and Browder, {T. E.} and Chang, {M. C.} and Y. Chao and A. Chen and Chen, {K. F.} and Chen, {W. T.} and Cheon, {B. G.} and Chiang, {C. C.} and R. Chistov and Cho, {I. S.} and Choi, {S. K.} and Y. Choi and Choi, {Y. K.} and S. Cole and J. Dalseno and M. Danilov and M. Dash and A. Drutskoy and S. Eidelman and D. Epifanov and S. Fratina and M. Fujikawa and K. Furukawa and N. Gabyshev and P. Goldenzweig and B. Golob and H. Ha and J. Haba and T. Hara and K. Hayasaka and H. Hayashii and M. Hazumi and D. Heffernan and T. Hokuue and Y. Hoshi and Hsiung, {Y. B.} and Hyun, {H. J.} and T. Iijima and K. Ikado and K. Inami and A. Ishikawa and H. Ishino and R. Itoh and M. Iwabuchi and M. Iwasaki and Y. Iwasaki and Kah, {D. H.} and H. Kaji and Kataoka, {S. U.} and H. Kawai and T. Kawasaki and A. Kibayashi and H. Kichimi and E. Kikutani and Kim, {H. J.} and Kim, {S. K.} and Kim, {Y. J.} and K. Kinoshita and S. Korpar and Y. Kozakai and P. Kri{\v z}an and P. Krokovny and R. Kumar and Kuo, {C. C.} and A. Kuzmin and Kwon, {Y. J.} and Lee, {M. J.} and Lee, {S. E.} and T. Lesiak and J. Li and Y. Liu and D. Liventsev and F. Mandl and D. Marlow and S. McOnie and T. Medvedeva and T. Mimashi and W. Mitaroff and K. Miyabayashi and H. Miyake and Y. Miyazaki and R. Mizuk and T. Mori and Nakamura, {T. T.} and E. Nakano and M. Nakao and H. Nakazawa and S. Nishida and O. Nitoh and S. Noguchi and T. Nozaki and S. Ogawa and Y. Ogawa and T. Ohshima and S. Okuno and Olsen, {S. L.} and H. Ozaki and G. Pakhlova and Park, {C. W.} and H. Park and Peak, {L. S.} and R. Pestotnik and M. Peters and Piilonen, {L. E.} and A. Poluektov and H. Sahoo and Y. Sakai and O. Schneider and J. Sch{\"u}mann and Schwartz, {A. J.} and R. Seidl and K. Senyo and Sevior, {M. E.} and M. Shapkin and Shen, {C. P.} and H. Shibuya and T. Shidara and S. Shinomiya and Shiu, {J. G.} and B. Shwartz and Singh, {J. B.} and A. Sokolov and A. Somov and S. Stani{\v c} and M. Stari{\v c} and K. Sumisawa and T. Sumiyoshi and S. Suzuki and O. Tajima and F. Takasaki and N. Tamura and M. Tanaka and M. Tawada and Taylor, {G. N.} and Y. Teramoto and I. Tikhomirov and K. Trabelsi and S. Uehara and K. Ueno and T. Uglov and S. Uno and P. Urquijo and Y. Ushiroda and Y. Usov and G. Varner and Varvell, {K. E.} and K. Vervink and S. Villa and Wang, {C. C.} and Wang, {C. H.} and Wang, {M. Z.} and Y. Watanabe and R. Wedd and J. Wicht and E. Won and Yabsley, {B. D.} and A. Yamaguchi and Y. Yamashita and M. Yamauchi and M. Yoshida and Yuan, {C. Z.} and Y. Yusa and Zhang, {C. C.} and Zhang, {Z. P.} and V. Zhilich and V. Zhulanov and A. Zupanc",

year = "2008",

month = mar,

day = "20",

doi = "10.1038/nature06827",

language = "English",

volume = "452",

pages = "332--335",

journal = "Nature",

issn = "0028-0836",

publisher = "Nature Publishing Group",

number = "7185",

}

Lin, SW, Unno, Y, Hou, WS, Chang, P, Adachi, I, Aihara, H, Akai, K, Arinstein, K, Aulchenko, V, Aushev, T, Aziz, T, Bakich, AM, Balagura, V, Barberio, E, Bay, A, Bedny, I, Bitenc, U, Bondar, A, Bozek, A, Bračko, M, Browder, TE, Chang, MC, Chao, Y, Chen, A, Chen, KF, Chen, WT, Cheon, BG, Chiang, CC, Chistov, R, Cho, IS, Choi, SK, Choi, Y, Choi, YK, Cole, S, Dalseno, J, Danilov, M, Dash, M, Drutskoy, A, Eidelman, S, Epifanov, D, Fratina, S, Fujikawa, M, Furukawa, K, Gabyshev, N, Goldenzweig, P, Golob, B, Ha, H, Haba, J, Hara, T, Hayasaka, K, Hayashii, H, Hazumi, M, Heffernan, D, Hokuue, T, Hoshi, Y, Hsiung, YB, Hyun, HJ, Iijima, T, Ikado, K, Inami, K, Ishikawa, A, Ishino, H, Itoh, R, Iwabuchi, M, Iwasaki, M, Iwasaki, Y, Kah, DH, Kaji, H, Kataoka, SU, Kawai, H, Kawasaki, T, Kibayashi, A, Kichimi, H, Kikutani, E, Kim, HJ, Kim, SK, Kim, YJ, Kinoshita, K, Korpar, S, Kozakai, Y, Križan, P, Krokovny, P, Kumar, R, Kuo, CC, Kuzmin, A, Kwon, YJ, Lee, MJ, Lee, SE, Lesiak, T, Li, J, Liu, Y, Liventsev, D, Mandl, F, Marlow, D, McOnie, S, Medvedeva, T, Mimashi, T, Mitaroff, W, Miyabayashi, K, Miyake, H, Miyazaki, Y, Mizuk, R, Mori, T, Nakamura, TT, Nakano, E, Nakao, M, Nakazawa, H, Nishida, S, Nitoh, O, Noguchi, S, Nozaki, T, Ogawa, S, Ogawa, Y, Ohshima, T, Okuno, S, Olsen, SL, Ozaki, H, Pakhlova, G, Park, CW, Park, H, Peak, LS, Pestotnik, R, Peters, M, Piilonen, LE, Poluektov, A, Sahoo, H, Sakai, Y, Schneider, O, Schümann, J, Schwartz, AJ, Seidl, R, Senyo, K, Sevior, ME, Shapkin, M, Shen, CP, Shibuya, H, Shidara, T, Shinomiya, S, Shiu, JG, Shwartz, B, Singh, JB, Sokolov, A, Somov, A, Stanič, S, Starič, M, Sumisawa, K, Sumiyoshi, T, Suzuki, S, Tajima, O, Takasaki, F, Tamura, N, Tanaka, M, Tawada, M, Taylor, GN, Teramoto, Y, Tikhomirov, I, Trabelsi, K, Uehara, S, Ueno, K, Uglov, T, Uno, S, Urquijo, P, Ushiroda, Y, Usov, Y, Varner, G, Varvell, KE, Vervink, K, Villa, S, Wang, CC, Wang, CH, Wang, MZ, Watanabe, Y, Wedd, R, Wicht, J, Won, E, Yabsley, BD, Yamaguchi, A, Yamashita, Y, Yamauchi, M, Yoshida, M, Yuan, CZ, Yusa, Y, Zhang, CC, Zhang, ZP, Zhilich, V, Zhulanov, V & Zupanc, A 2008, 'Difference in direct charge-parity violation between charged and neutral B meson decays', Nature, vol. 452, no. 7185, pp. 332-335. https://doi.org/10.1038/nature06827

TY - JOUR

T1 - Difference in direct charge-parity violation between charged and neutral B meson decays

AU - Lin, S. W.

AU - Unno, Y.

AU - Hou, W. S.

AU - Chang, P.

AU - Adachi, I.

AU - Aihara, H.

AU - Akai, K.

AU - Arinstein, K.

AU - Aulchenko, V.

AU - Aushev, T.

AU - Aziz, T.

AU - Bakich, A. M.

AU - Balagura, V.

AU - Barberio, E.

AU - Bay, A.

AU - Bedny, I.

AU - Bitenc, U.

AU - Bondar, A.

AU - Bozek, A.

AU - Bračko, M.

AU - Browder, T. E.

AU - Chang, M. C.

AU - Chao, Y.

AU - Chen, A.

AU - Chen, K. F.

AU - Chen, W. T.

AU - Cheon, B. G.

AU - Chiang, C. C.

AU - Chistov, R.

AU - Cho, I. S.

AU - Choi, S. K.

AU - Choi, Y.

AU - Choi, Y. K.

AU - Cole, S.

AU - Dalseno, J.

AU - Danilov, M.

AU - Dash, M.

AU - Drutskoy, A.

AU - Eidelman, S.

AU - Epifanov, D.

AU - Fratina, S.

AU - Fujikawa, M.

AU - Furukawa, K.

AU - Gabyshev, N.

AU - Goldenzweig, P.

AU - Golob, B.

AU - Ha, H.

AU - Haba, J.

AU - Hara, T.

AU - Hayasaka, K.

AU - Hayashii, H.

AU - Hazumi, M.

AU - Heffernan, D.

AU - Hokuue, T.

AU - Hoshi, Y.

AU - Hsiung, Y. B.

AU - Hyun, H. J.

AU - Iijima, T.

AU - Ikado, K.

AU - Inami, K.

AU - Ishikawa, A.

AU - Ishino, H.

AU - Itoh, R.

AU - Iwabuchi, M.

AU - Iwasaki, M.

AU - Iwasaki, Y.

AU - Kah, D. H.

AU - Kaji, H.

AU - Kataoka, S. U.

AU - Kawai, H.

AU - Kawasaki, T.

AU - Kibayashi, A.

AU - Kichimi, H.

AU - Kikutani, E.

AU - Kim, H. J.

AU - Kim, S. K.

AU - Kim, Y. J.

AU - Kinoshita, K.

AU - Korpar, S.

AU - Kozakai, Y.

AU - Križan, P.

AU - Krokovny, P.

AU - Kumar, R.

AU - Kuo, C. C.

AU - Kuzmin, A.

AU - Kwon, Y. J.

AU - Lee, M. J.

AU - Lee, S. E.

AU - Lesiak, T.

AU - Li, J.

AU - Liu, Y.

AU - Liventsev, D.

AU - Mandl, F.

AU - Marlow, D.

AU - McOnie, S.

AU - Medvedeva, T.

AU - Mimashi, T.

AU - Mitaroff, W.

AU - Miyabayashi, K.

AU - Miyake, H.

AU - Miyazaki, Y.

AU - Mizuk, R.

AU - Mori, T.

AU - Nakamura, T. T.

AU - Nakano, E.

AU - Nakao, M.

AU - Nakazawa, H.

AU - Nishida, S.

AU - Nitoh, O.

AU - Noguchi, S.

AU - Nozaki, T.

AU - Ogawa, S.

AU - Ogawa, Y.

AU - Ohshima, T.

AU - Okuno, S.

AU - Olsen, S. L.

AU - Ozaki, H.

AU - Pakhlova, G.

AU - Park, C. W.

AU - Park, H.

AU - Peak, L. S.

AU - Pestotnik, R.

AU - Peters, M.

AU - Piilonen, L. E.

AU - Poluektov, A.

AU - Sahoo, H.

AU - Sakai, Y.

AU - Schneider, O.

AU - Schümann, J.

AU - Schwartz, A. J.

AU - Seidl, R.

AU - Senyo, K.

AU - Sevior, M. E.

AU - Shapkin, M.

AU - Shen, C. P.

AU - Shibuya, H.

AU - Shidara, T.

AU - Shinomiya, S.

AU - Shiu, J. G.

AU - Shwartz, B.

AU - Singh, J. B.

AU - Sokolov, A.

AU - Somov, A.

AU - Stanič, S.

AU - Starič, M.

AU - Sumisawa, K.

AU - Sumiyoshi, T.

AU - Suzuki, S.

AU - Tajima, O.

AU - Takasaki, F.

AU - Tamura, N.

AU - Tanaka, M.

AU - Tawada, M.

AU - Taylor, G. N.

AU - Teramoto, Y.

AU - Tikhomirov, I.

AU - Trabelsi, K.

AU - Uehara, S.

AU - Ueno, K.

AU - Uglov, T.

AU - Uno, S.

AU - Urquijo, P.

AU - Ushiroda, Y.

AU - Usov, Y.

AU - Varner, G.

AU - Varvell, K. E.

AU - Vervink, K.

AU - Villa, S.

AU - Wang, C. C.

AU - Wang, C. H.

AU - Wang, M. Z.

AU - Watanabe, Y.

AU - Wedd, R.

AU - Wicht, J.

AU - Won, E.

AU - Yabsley, B. D.

AU - Yamaguchi, A.

AU - Yamashita, Y.

AU - Yamauchi, M.

AU - Yoshida, M.

AU - Yuan, C. Z.

AU - Yusa, Y.

AU - Zhang, C. C.

AU - Zhang, Z. P.

AU - Zhilich, V.

AU - Zhulanov, V.

AU - Zupanc, A.

PY - 2008/3/20

Y1 - 2008/3/20

N2 - Equal amounts of matter and antimatter are predicted to have been produced in the Big Bang, but our observable Universe is clearly matter-dominated. One of the prerequisites for understanding this elimination of antimatter is the nonconservation of charge-parity (CP) symmetry. So far, two types of CP violation have been observed in the neutral K meson (K0) and B meson (B0) systems: CP violation involving the mixing between K0 and its antiparticle (and likewise for B0 and ), and direct CP violation in the decay of each meson. The observed effects for both types of CP violation are substantially larger for the B0 meson system. However, they are still consistent with the standard model of particle physics, which has a unique source of CP violation that is known to be too small to account for the matter-dominated Universe. Here we report that the direct CP violation in charged B±→K±π0 decay is different from that in the neutral B0 counterpart. The direct CP-violating decay rate asymmetry, (that is, the difference between the number of observed B-→K-π0 event versus B +→K+ π0 events, normalized to the sum of these events) is measured to be about +7%, with an uncertainty that is reduced by a factor of 1.7 from a previous measurement. However, the asymmetry for versus B0→K+π- is at the -10% level. Although it is susceptible to strong interaction effects that need further clarification, this large deviation in direct CP violation between charged and neutral B meson decays could be an indication of new sources of CP violation - which would help to explain the dominance of matter in the Universe.

AB - Equal amounts of matter and antimatter are predicted to have been produced in the Big Bang, but our observable Universe is clearly matter-dominated. One of the prerequisites for understanding this elimination of antimatter is the nonconservation of charge-parity (CP) symmetry. So far, two types of CP violation have been observed in the neutral K meson (K0) and B meson (B0) systems: CP violation involving the mixing between K0 and its antiparticle (and likewise for B0 and ), and direct CP violation in the decay of each meson. The observed effects for both types of CP violation are substantially larger for the B0 meson system. However, they are still consistent with the standard model of particle physics, which has a unique source of CP violation that is known to be too small to account for the matter-dominated Universe. Here we report that the direct CP violation in charged B±→K±π0 decay is different from that in the neutral B0 counterpart. The direct CP-violating decay rate asymmetry, (that is, the difference between the number of observed B-→K-π0 event versus B +→K+ π0 events, normalized to the sum of these events) is measured to be about +7%, with an uncertainty that is reduced by a factor of 1.7 from a previous measurement. However, the asymmetry for versus B0→K+π- is at the -10% level. Although it is susceptible to strong interaction effects that need further clarification, this large deviation in direct CP violation between charged and neutral B meson decays could be an indication of new sources of CP violation - which would help to explain the dominance of matter in the Universe.

UR - http://www.scopus.com/inward/record.url?scp=41149094975&partnerID=8YFLogxK

U2 - 10.1038/nature06827

DO - 10.1038/nature06827

M3 - Article

AN - SCOPUS:41149094975

SN - 0028-0836

VL - 452

SP - 332

EP - 335

JO - Nature

JF - Nature

IS - 7185

ER -

Difference in direct charge-parity violation between charged and neutral B meson decays

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