Related papers: Probing the top quark flavor-changing couplings at…
The associated production of a single-top with opposite-sign same-flavor (OSSF) di-leptons, $pp \to t \ell^+ \ell^-$ and $ pp \to t \ell^+ \ell^- + j$ ($j=$light jet), can lead to striking tri-lepton $pp \to \ell^\prime \ell^+ \ell^- + X$…
We present a search for flavor changing neutral currents in decays of top quarks. The analysis is based on a search for ttbar -> l'null + jets (l, l' = e, mu) final states using 4.1 fb^-1 of integrated luminosity of ppbar collisions at…
The combined symmetry of charge conjugation and parity ($C\!P$) is tested in the hadronic transition $\psi(3686)\to\pi^+\pi^{-}J/\psi$, utilizing a dataset of 2.7 billion $\psi(3686)$ events collected by the BESIII detector at the BEPCII…
Top decays into a light Higgs boson and an up or charm quark can reach detectable levels in Standard Model extensions with two Higgs doublets or with new exotic quarks, and in the Minimal Supersymmetric Standard Model. Using both a standard…
Searches for flavor changing neutral currents in top production and decay using data collected by the Compact Muon Solenoid (CMS) experiment at $\sqrt{s}$ = 7 and 8 TeV are presented, corresponding to an integrated luminosity of around 5…
In this paper, we study the triple top quark production at the future high-energy proton-proton colliders to probe the four-fermion interactions involving three top quarks. We employ the Standard Model Effective Field Theory (SMEFT) to find…
It is argued that the topcolor models recently proposed by Hill [1] may face significant constraints from flavor-changing neutral current processes (such as $B-\bar{B}$ mixing) unless the mixing angles between down-type quarks are small.…
A direct search for charged lepton-flavour violation in top-quark decays is presented. The data analysed correspond to $79.8\ \text{fb}^{-1}$ of proton--proton collisions at a centre-of-mass energy of $\sqrt{s}=13\ \text{TeV}$ recorded by…
Flavor-changing signatures of Lorentz and CPT violation involving muon-electron conversions in muonic atoms are studied using effective field theory. Constraints on coefficients for Lorentz violation at parts in $10^{-12}$ GeV$^{-1}$ for…
We report on the physics potential of a proposed conversion of the CESR machine and the CLEO detector to a charm and QCD factory: ``CLEO-c and CESR-c'' that will make crucial contributions to quark flavor physics this decade, and may offer…
A search for charged-lepton flavour violation (CLFV) in top quark (t) production and decay is presented. The search uses proton-proton collision data corresponding to 138 fb$^{-1}$ collected with the CMS experiment at $\sqrt{s}$ = 13 TeV.…
With the full Tevatron Run II and early LHC data samples, the opportunity for furthering our understanding of the properties of the top quark has never been more promising. Although the current knowledge of the top quark comes largely from…
The Circular Electron-Positron Collider (CEPC) is a future Higgs factory proposed by the Chinese high energy physics community. It will operate at a center-of-mass energy of 240-250 GeV and is expected to accumulate an integrated luminosity…
Recently, experimental collaborations have reported $\mathcal{O}(10)$ upper limits on the signal strength of four-top production at the LHC, which already leads to competitive constraints on certain type of top-quark operators. On the other…
We obtain a new constraint on the CP-violating flavor mixing between the left-handed top scalar quark (\tilde{t}_L) and charm scalar quark (\tilde{c}_L), by considering a chargino loop contribution to chromo-electric dipole moment of…
Top quarks are a prime system for hunting for new physics. Nonetheless, two decades on from their discovery few of their couplings have been measured to high precision. We present an overview of current determinations and the expected…
The observation of lepton flavor violation indicates new physics beyond the Standard Model. Lepton colliders are ideal facilities to probe charged lepton flavor violation (CLFV) signals induced by new physics at high energy. In this work we…
In absence of any distinct evidence of new physics phenomena at the LHC, an increasing number of experimental studies aim at probing anomalous effects with an effective field theory (EFT) that represents a comprehensive approach for…
We report on the physics potential of a proposed conversion of the CESR machine and the CLEO detector to a charm and QCD factory: CLEO-c and CESR-c that will make crucial contributions to flavor physics in this decade and offers our best…
The measurement of the top-quark anomalous electromagnetic couplings is one of the most important goals of the top-quark physics program in the present and future collider experiments. This would provide direct information on the…