Probing New Physics from Top Quark FCNC Processes at LHC: A Mini Review

TL;DR

This review discusses how top quark flavor-changing neutral current processes, highly suppressed in the Standard Model, could be significantly enhanced in new physics models like MSSM and TC2, offering potential signals at the LHC.

Contribution

It compares predictions of top quark FCNC processes in MSSM and TC2 models, highlighting the potential for large enhancements and experimental detectability at the LHC.

Findings

TC2 model predicts the largest enhancements in FCNC processes.

Most FCNC channels are accessible in TC2, few in MSSM.

Enhancements can be several orders of magnitude over SM predictions.

Abstract

Since the top quark FCNC processes are extremely supressed in the Standard Model (SM) but could be greatly enhanced in some new physics models, they could serve as a smoking gun for new physics hunting at the LHC. In this brief review we summarize the new physics predictions for various top quark FCNC processes at the LHC by focusing on two typical models: the minimal supersymmetric model (MSSM) and the topcolor-assisted technicolor (TC2) model. The conclusion is: (1) Both new physics models can greatly enhance the SM predictions by several orders; (2) The TC2 model allows for largest enhancement, and for each channel the maximal prediction is much larger than in the MSSM; (3) Compared with the $3\sigma$ sensitivity at the LHC, only a couple of channels are accessible for the MSSM while most channles are accesible for the TC2 model.