2011/05/31 by Xin-Qiang Li, Ya-Dong Yang, X. Yuan +1
Physics and Astronomy · #Asymmetry #B meson #Branching fraction #Coupling (piping) #High-Energy Particle Collisions Research #Isospin #Large Hadron Collider #Meson #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Radiative transfer #Upper and lower bounds #hep-ex #hep-ph
paper · pdf · doi:10.1007/jhep08(2011)075
25 pages, 15 figures, pdflatex
arxiv created 2011/07/14 · openalex publication_date 2011/08/01 · arxiv updated 2015/05/28 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The top-quark FCNC processes will be searched for at the CERN LHC, which are correlated with the B-meson decays. In this paper, we study the effects of top-quark anomalous interactions tqγ in the exclusive radiative B→ K^*γ and B→ργ decays. With the current experimental data of the branching ratios, the direct CP and the isospin asymmetries, bounds on the coupling κtcRγ from B→ K^*γ and κtuRγ from B→ ργ decays are derived, respectively. The bound on |κtcRγ| from \mathcal B(B→ K*γ) is generally compatible with that from \mathcal B(B→ Xsγ). However, the isospin asymmetry Δ(K*γ) further restrict the phase of κtcRγ, and the combined bound results in the upper limit, \mathcal B(t→ cγ)<0.21%, which is lower than the CDF result. For real κtcRγ, the upper bound on \mathcal B(t→ cγ) is about of the same order as the 5σ discovery potential of ATLAS with an integrated luminosity of 10 \rm fb-1. For B→ργ decays, the NP contribution is enhanced by a large CKM factor |Vud/Vtd|, and the constraint on tuγ coupling is rather restrictive, \mathcal B(t→ uγ)<1.44× 10-5. With refined measurements to be available at the LHCb and the future super-B factories, we can get close correlations between B→ V γ and the rare t→ qγ decays, which will be studied directly at the LHC ATLAS and CMS.