All Results

Top quark three-body decays in R-violating MSSM

Heng,Z; Lu,G; Wu,L; Yang,JMSubjects:

In the minimal supersymmetric standard model the R-parity violating interactions can trigger various exotic three-body decays for the top quark, which may be accessible at the LHC. In this work we examine the R-violating decays t-> c X_1 X_2, which includ |

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We examine the lepton flavor-changing processes in R -parity violating MSSM. First, we update the constraints on the relevant R -violating couplings by using the latest data on the rare decays ? i → ? j γ . We find that the updated constraints are much st |

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We examine various direct and indirect constraints on the lepton-specific two-Higgs doublet model and scrutinize the property of the Higgs bosons in the allowed parameter space. These constraints come from the precision electroweak data, the direct search |

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The top quark forward-backward asymmetry A_{FB}^{t} measured at the Tevatron is above the Standard Model prediction by more than 2-sigma deviation, which might be a harbinger for new physics. In this work we examine the new physics contribution to A_{FB}^ |

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Extensions of the Standard Model often predict new chiral interactions for top quark, which will contribute to top quark spin correlation and polarization in tt?tt?t\bar{t} production at the LHC. In this work, under the constraints from the current Tevatr |

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The anomaly of the top quark forward-backward asymmetry AtFBAFBtA^t_{FB} observed at the Tevatron can be explained by the t-channel exchange of a neutral gauge boson (Z') which has sizable flavor changing coupling for top and up quarks. This gauge boson c |

Testing new physics models by top charge asymmetry and polarization at the LHC

Cao,J; Hikasa,K; Wang,L; Wu,L; Yang,JMSubjects:

As a top quark factory, the LHC can test the new physics models used to explain the top quark forward-backward asymmetry A^t_FB measured at the Tevatron. In this work we perform a comparative study for two such models: the W'-model and the color triplet d |

Top quark forward-backward asymmetry and charge asymmetry in left-right twin Higgs model

Wang,L; Wu,L; Yang,JMSubjects:

In order to explain the Tevatron anomaly of the top quark forward-backward asymmetry AtFBAFBtA_{FB}^t in the left-right twin Higgs model, we choose to give up the lightest neutral particle of h^h^\hat{h} field as a stable dark matter candidate. Then a new |

Probing topcolor-assisted technicolor from top charge asymmetry and triple-top production at the LHC

Han,C; Liu,N; Wu,L; Yang,JMSubjects:

In a topcolor-assisted technicolor model (TC2) with large FCNC top quark couplings, we study its correlated contributions to the top quark forward-backward asymmetry (AF B ) at the Tevatron, the top charge asymmetry (AC) and the triple-top production at the LHC. Under current constraints on the top quark from the LHC and Tevatron (such as the total and differential production rates), we scan the parameter space of such a TC2 model. We find that in the allowed parameter space the TC2 model can explain the Tevatron measured AFB at 2σ level, but meanwhile significantly enhance AC at the LHC. Such enhanced AC, albeit currently allowed by the LHC measurement at 2σ level, will serve as a test of TC2 with the improvement of measurement precision at the LHC. Then with all the constraints (including the requirement to explain AF B at 2σ level and satisfying the current LHC measurement of AC at 2σ level), we find that the TC2 model can induce sizable triple-top production at the 14 TeV LHC (the production rate can maximally reach 16 pb). Due to the low SM backgrounds, the triple-top production can also be a good probe for TC2 model, complementary to AC. |

Probing Natural SUSY from Stop Pair Production at the LHC

Cao,J; Han,C; Wu,L; Yang,JM; Zhang,YSubjects:

We consider the natural supersymmetry scenario in the framework of the R-parity conserving minimal supersymmetric standard model (called natural MSSM) and examine the observability of stop pair production at the LHC. We first scan the parameters of this s |