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Chong-Sheng Li

Publications and source records attributed to Chong-Sheng Li.

7 recordsLinked to original sources

CP Asymmetry in $\bar B^0\to K^- π^+$ from SUSY Flavor Changing Interactions

Recently Babar and Belle collaborations have measured direct CP asymmetry $A_{CP}=-0.114\pm 0.020$ in $\bar B^0 \to K^- π^+$. The experimental value is substantially different from QCD factorization prediction. We show that SUSY flavor changing neutral current interaction via gluonic dipole can explain the difference. CP asymmetries in other $B\to Kπ$ decays are predicted to be sizeable. Taking this asymmetry as a constraint, we find that the allowed SUSY parameter space is considerably reduced compared with constraint from $B\to X_s γ$ alone. We also find that the allowed time dependent CP asymmetries $S_f$ in $\bar B^0 \to \bar K^{* 0}γ\to π^0 K_S γ$ and $\bar B^0\to ϕK_S$ to be large. These predictions are quite different than those predicted in the Standard Model and can be tested in the near future.

hep-ph

Top Quark Loop Corrections to the Neutral Higgs Boson Production at the Fermilab Tevatron

We calculate the $O(αm_t^2/m^2_W)$ corrections arising from diagrams involving the top-quark loops to the light neutral Higgs boson production via $q\bar q'\to WH$ at the Fermilab Tevatron in both the standard model and the minimal supersymmetric model. In contrast to the QCD correction which increases the tree-level cross section, the corrections imply a few percent reduction in the production cross section relative to the tree-leve results.

hep-ph

Supersymmetric Electroweak Corrections to Top Quark Production at LHC

The $αm_t^2/m_W^2$ order supersymmetric electroweak corrections arising from loops of chargino, neutralino, and squark to top quark pair production by $gg$ fusion at LHC are calculated in the minimal supersymmetric model. We found that the corrections amount about a few percent.

hep-ph

Radiative Higgs Boson Decays H\to f\bar{f}γBeyond the Standard Model

Neutral Higgs boson radiative decays of the form h_0, H, A \to f\bar{f}γ, in the light fermion limit $m_f->0, are calculated in the two Higgs doublet model at one-loop level. Comparisons with the calculation within the standard model are given, which indicates that these two models are distinguishable in the decay mode fermion-antifermion -photon. Our results show that the concerned process may stand as an implement to identify the Higgs belongings in case there is a intermediate mass Higgs detected.

hep-ph

Supersymmetric QCD Corrections to Top Quark Pair Production in Photon-Photon Collision

Supersymmetric QCD corrections to top quark pair production by photon fusion are calculated in the minimal supersymmetric standard model taking into account of the effects of stops in the corrections to the total cross-section of t anti-t production at the future electron-positron linear collider. We find that the relative correction can be a few percent for reasonable values of the parameters.

hep-ph

Heavy Fermion Screening Effects and Gauge Invariance

We show that the naively expected large virtual heavy fermion effects in low energy processes may be screened if the process under consideration contains external gauge bosons constrained by gauge invariance. We illustrate this by a typical example of the process $γγ\to b \bar{b}$. Phenomenological implications are also briefly indicated.

hep-ph