# 29th International Symposium on Lepton Photon Interactions at High Energies

5-10 August 2019
America/Toronto timezone

## Effective Lagrangian Approach to Top Decay via Flavor Changing Neutral Current

8 Aug 2019, 10:30
30m
Harbour Ballroom (Westin Harbour Castle, Toronto Canada)

### Harbour Ballroom

#### Westin Harbour Castle, Toronto Canada

1 Harbour Square, Toronto, Ontario, Canada
Poster submission Collider -- Beyond Standard Model Searches

### Speaker

Kazumasa OHKUMA (Okayama University of Science)

### Summary

We study possible non-standard tuZ and tcZ interactions, which induce flavor-changing neutral-current decays of the top quark, in the effective-Lagrangian framework. The corresponding Lagrangian consists of four kinds of non- standard couplings coming from SU(3)xSU(2)xU(1) invariant dimension-6 effective operators. The four coupling constants in each interaction are treated as complex numbers independent of each other, and constraints on them are derived by using the present experimental limits of the branching fractions for t -> u Z and t -> c Z processes. Future improvements of those constraints are also discussed as well as possibilities of measurements of these couplings at the High-Luminosity Large Hadron Collider. In addition, correlations of non-standard couplings reproducing experimental results are presented.

### Primary authors

Kazumasa OHKUMA (Okayama University of Science) Zenro Hioki (University of Tokushima) Dr Akira Uejima (Okayama University of Science)