B→Kη（＇） decays in the SM with fourth generation fermions
By employing the perturbative QCD （pQCD） factorization approach, we calculate the new physics contributions to the four B→Kη（＇） decays in the Standard Model （SM） with a fourth generation of fermions （SM4）, induced by the loop diagrams involving t＇ quark. Within the considered parameter space of the...
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| Published in | Chinese physics C Vol. 38; no. 7; pp. 9 - 13 |
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| Main Author | |
| Format | Journal Article |
| Language | English |
| Published |
01.07.2014
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| Subjects | |
| Online Access | Get full text |
| ISSN | 1674-1137 2058-6132 0254-3052 |
| DOI | 10.1088/1674-1137/38/7/073102 |
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| Summary: | By employing the perturbative QCD （pQCD） factorization approach, we calculate the new physics contributions to the four B→Kη（＇） decays in the Standard Model （SM） with a fourth generation of fermions （SM4）, induced by the loop diagrams involving t＇ quark. Within the considered parameter space of the SM4 we find that： （a） the next-to-leading order （NLO） pQCD predictions for the branching ratios and CP-violating asymmetries in both the SM and SM4 generally agree with the data within one standard deviation; （b） for Br（B→Kη）, the inclusion of the fourth generation contributions can improve the agreement between the theoretical predictions and the data effectively; （c） however, for Br（B→Kη＇） the decrease due to t＇ loops is disfavored by the data; and, （d） the new physics corrections to the CP-violating asymmetries of the considered decays are only about 10%. |
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| Bibliography: | 11-5641/O4 perturbative QCD factorization approach, B meson decays, standard model with fourth generation,CP violatoin By employing the perturbative QCD （pQCD） factorization approach, we calculate the new physics contributions to the four B→Kη（＇） decays in the Standard Model （SM） with a fourth generation of fermions （SM4）, induced by the loop diagrams involving t＇ quark. Within the considered parameter space of the SM4 we find that： （a） the next-to-leading order （NLO） pQCD predictions for the branching ratios and CP-violating asymmetries in both the SM and SM4 generally agree with the data within one standard deviation; （b） for Br（B→Kη）, the inclusion of the fourth generation contributions can improve the agreement between the theoretical predictions and the data effectively; （c） however, for Br（B→Kη＇） the decrease due to t＇ loops is disfavored by the data; and, （d） the new physics corrections to the CP-violating asymmetries of the considered decays are only about 10%. CHENG Shan,FAN Ying-Ying,XIAO Zhen-Jun（Departmen of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210023, China） |
| ISSN: | 1674-1137 2058-6132 0254-3052 |
| DOI: | 10.1088/1674-1137/38/7/073102 |