Novel flavour-changing neutral currents in the top quark sector

• Autor(a) principal: Castro, Nuno Filipe
• Data de Publicação: 2020
• Outros Autores: Chala, Mikael, Peixoto, Ana, Ramos, Maria
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Texto Completo: http://hdl.handle.net/1822/70347
• topic: Rare decays; Top quark; Leptons; Flavour-changing neutral currents; Beyond Standard Model; Hadron-Hadron scattering (experiments); Top physics; Ciências Naturais::Ciências Físicas; Science & Technology

We demonstrate that flavour-changing neutral currents in the top sector, mediated by leptophilic scalars at the electroweak scale, can easily arise in scenarios of new physics, and in particular in composite Higgs models. We moreover show that such interactions are poorly constrained by current experiments, while they can be searched for at the LHC in rare top decays and, more generally, in the channels $pp\to tS(S)+j$, with $S\to\ell^+\ell^-$. We provide dedicated analyses in this respect, obtaining that cut-off scales as large as $\Lambda\sim$ 90 TeV can be probed with an integrated luminosity of $\mathcal{L} = 150$ fb$^{-1}$.