Based on a data sample of 384 million BB pairs collected with the BABAR detector at the PEP-Ⅱ asymmetric e ＋ e ￣ storage ring,we measure branching fractions,direct CP,isospin and lepton-flavor asymmetries for the r...Based on a data sample of 384 million BB pairs collected with the BABAR detector at the PEP-Ⅱ asymmetric e ＋ e ￣ storage ring,we measure branching fractions,direct CP,isospin and lepton-flavor asymmetries for the rare decays B → K （＊） l ＋ l￣ in two di-lepton mass bins above and below the J/ψ resonance.For the B → K＊ l ＋ l￣ decay,we also measure the K＊ longitudinal polarization fraction and the di-lepton forwardbackward asymmetry.展开更多
We discuss the implications of the recently reported R_K and R_（K＊） anomalies, the lepton flavor nonuniversality in the B → Kl~＋l^-and B → K~＊l~＋~l- decay channels. Using two sets of hadronic inputs of form fa...We discuss the implications of the recently reported R_K and R_（K＊） anomalies, the lepton flavor nonuniversality in the B → Kl~＋l^-and B → K~＊l~＋~l- decay channels. Using two sets of hadronic inputs of form factors, we perform a fit of new physics to the R_K and R_（K＊） data, and significant new physics contributions are found. We suggest the study of lepton flavor universality in a number of related rare B,Bs,Bc and Λb decay channels, and in particular we give predictions for the μ-to-e ratios of decay widths with different polarizations of the final state particles, and of the b → dl~＋l^- processes, which are presumably more sensitive to the structure of the underlying new physics. With the new physics contributions embedded in the Wilson coefficients, we present theoretical predictions for lepton flavor non-universality in these processes.展开更多
文摘Based on a data sample of 384 million BB pairs collected with the BABAR detector at the PEP-Ⅱ asymmetric e ＋ e ￣ storage ring,we measure branching fractions,direct CP,isospin and lepton-flavor asymmetries for the rare decays B → K （＊） l ＋ l￣ in two di-lepton mass bins above and below the J/ψ resonance.For the B → K＊ l ＋ l￣ decay,we also measure the K＊ longitudinal polarization fraction and the di-lepton forwardbackward asymmetry.
基金Supported by National Natural Science Foundation of China(11575110,11655002,11735010)Natural Science Foundation of Shanghai(15DZ2272100,15ZR1423100)+1 种基金Young Thousand Talents PlanKey Laboratory for Particle Physics,Astrophysics and Cosmology,Ministry of Education
文摘We discuss the implications of the recently reported R_K and R_（K＊） anomalies, the lepton flavor nonuniversality in the B → Kl~＋l^-and B → K~＊l~＋~l- decay channels. Using two sets of hadronic inputs of form factors, we perform a fit of new physics to the R_K and R_（K＊） data, and significant new physics contributions are found. We suggest the study of lepton flavor universality in a number of related rare B,Bs,Bc and Λb decay channels, and in particular we give predictions for the μ-to-e ratios of decay widths with different polarizations of the final state particles, and of the b → dl~＋l^- processes, which are presumably more sensitive to the structure of the underlying new physics. With the new physics contributions embedded in the Wilson coefficients, we present theoretical predictions for lepton flavor non-universality in these processes.
