2013/10/31 by Shan Cheng, Ying-Ying Fan, Zhen-Jun Xiao
Physics and Astronomy · #Branching fraction #Factorization #Fermion #Fourth generation #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Perturbative QCD #Physics beyond the Standard Model #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Standard Model (mathematical formulation) #hep-ex #hep-ph
paper · pdf · doi:10.1088/1674-1137/38/7/073102
9 pages, no figure. two references added. to be published in Chinese Physics C
arxiv created 2013/11/27 · openalex publication_date 2014/07/01 · arxiv updated 2015/06/17 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
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%.