Refined analysis and updated constraints on general non-standard tbW couplings

Full analysis of general non - standard tbW couplings

Possible non-standard couplings which could contribute to the t → bW process are studied based on the effective-Lagrangian approach. The corresponding effective Lagrangian consists of four kinds of dimension-6 effective operators, each of which has an independent coupling constant. In this analysis, all those couplings are treated as complex numbers and constraints on them are estimated by usin...

Analysis of tbW and ttZ couplings from CLEO and LEP/SLC data

We update the constraints on anomalous dimension four t-b-W and t-t-Z couplings by using CLEO b → sγ and LEP/SLC precision Z-pole data. It is found that the data imposes very stringent bounds on them. Moreover, the 2σ pull from SM predictions of ALR(hadrons), Ab and AFB(b) have little chance of being explained by the strongly constrained anomalous couplings. PACS numbers: 14.65.Ha, 12.39.Fe, 12...

→ tt̄H with Non - standard Higgs Boson Couplings

Constraints on Charged - Higgs Couplings

Using the experimental value of the Et -KS mass difference, we derive constraints on charged-Higgs couplings in gauge theories of the weak and electromagnetic interactions. These bounds severely restrict the possible magnitude of charged-Higgs effects in K and D meson decays.' Our results are based on the observation that charge-Higgs exchange contributions to K"go mixing are of order l/g where...

Probing Non-standard Top Couplings Using spin-correlation

Top spin correlation has been shown to be nontrivial in hadronic top-pair production, and can be realized by the asymmetries of the decay products of the top quark and antiquark. We show in this work that the top spin correlation is a sensitive probe to the anomalous top-quark couplings beyond the standard model. Specifically, we look at the anomalous chromomagnetic and chromoelectric dipole mo...