相关论文: CP violating anomalous top-quark couplings at the …
The potential of ep collision to prospect for anomalous Wtb vertex is discussed from the single top quark production process $ep\to t\bar{\nu}+X$ for TESLA+HERAp and CLIC+LHC energies. Sensitivities to anomalous couplings $F_{2L}$ and…
We present a quantitative study on sensitivities to the top-decay anomalous couplings, taking into account realistic experimental conditions expected at Tevatron and LHC. A double angular distribution of W and charged lepton in the top…
In the presence of an electric dipole coupling of t-tbar to a photon, and an analogous "weak" dipole coupling to the Z, CP violation in the process e+e- --> t tbar results in modified polarization of the top and anti-top. This polarization…
Considering the experimental constraints given by CMS collaboration at $\sqrt{s} = 8$ TeV on the strength of top quark flavour-changing neutral-current (FCNC) couplings $tq\gamma$ and $tqg$, we investigate the production of top quark in…
The effects of CP violating anomalous ZZZ and gammaZZ vertices in ZZ production are determined. We present the differential cross-section for e+e- -> ZZ with dependence on the spins of the Z bosons. It is shown that from the different spin…
We investigate the top quark anomalous Flavor Changing Neutral Current (FCNC) $tqg$ interactions to probe limits on the couplings $\zeta_c$ and $\zeta_u$ through the $qg \to l\nu b$ signal suprocess at FCC-hh collider with center of mass…
The cross section for production at the 7 TeV LHC has been measured. For the first time it therefore becomes possible to measure Z couplings to top quarks. Interpreting the notorious LEP1 anomaly on Z couplings to b quarks in terms of an…
We use the associated production of top-quark pairs with a generic scalar boson at the LHC to explore the sensitivity of a large set of observables to the sign of the CP mixing angle, present in the coupling between the scalar boson and the…
We study the possibility for the process $pp \rightarrow p\gamma p \rightarrow pW^-t(W^+\bar t)X$ with anomalous Wtb couplings in a model independent effective Lagrangian approach at the LHC. We find 95% confidence level bounds on the…
Top pair production at LHC is the ideal place to search for nonstandard Wtb couplings in t -> W b -> l nu b decays. The lb forward-backward asymmetry in the W rest frame is very sensitive to sigma_{mu nu} couplings, and can spot one-loop…
We study a decay rate asymmetry of the top quark in the supersymmetric standard model, taking into account the constraints from the electric dipole moments of the neutron and the electron. One CP-violating phase contained in the…
In this work, we study the new physics effects arising due the presence of anomalous $Wtb$ vertex through the semileptonic decay modes of the top-quark at the Large Hadron Collider. An estimate on the sensitivities of the aforementioned…
In this paper, we study CP violation in $\Lambda_c^+\to BP$ and $\Lambda_c^+\to BV$ decays, where $B,P$ and $V$ denote a light spin-1/2 baryon, pseudoscalar and a vector meson respectively. In these processes the $T$ odd CP violating…
We present a systematic analysis of the angular distribution of Bbar -> Kbar^\ast (-> Kbar pi) l^+ l^- decays with l = e, mu in the low recoil region (i.e. at high dilepton invariant masses of the order of the mass of the b-quark) to…
Observation of top quark flavor changing neutral process $t\to c +\gamma$ at the LHC would be the signal of physics beyond the Standard Model. If anomalous $t\to c\gamma$ coupling exists, it will affect the precisely measured…
We show that a search for $e^+ e^- \to t \bar q$ $(\bar q = \bar c, \bar u)$ events at LEP--2 collider provide a possibility to improve significantly the modern constraints on coupling constants of anomalous $t$--quark interaction via…
Generically, non-Standard-Model particles contribute to processes with order-one charge-parity (CP) violating phases, as CP is not a fundamental symmetry of nature. The exploration of CP violation becomes therefore a sensitive search for…
Violations of the Lorentz and CPT symmetries can appear as observable effects in the direct production of top quarks and their subsequent decays. Earlier results for the $q\bar{q}$ production process for $t\bar{t}$ pairs have been extended…
We calculate the contribution of anomalous top-quark interaction with a gluon, photon, and $Z$-boson (FCNC) to $t \bar t$ pair production in hadronic collisions. Using the current data from Run~1 of the Tevatron we evaluate the upper limit…
We consider the top quark charge asymmetry in the process $pp \to t\bar{t}+\gamma$ at the 13 TeV LHC. The genuine tree level asymmetry in the $q\bar{q}$ channel is large with about -12%. However, the symmetric $gg$ channel, photon radiation…