Mixed electroweak-QCD corrections to e^+e^-→μ^+μ^-H at CEPC with finite-width effect

The associated production of Higgs boson with a muon pair, e^+e^-→μ+μ-H, is one of the golden channels to pin down the properties of the Higgs boson in the prospective Higgs factories exemplified by CEPC.The projected accuracy of the corresponding cross section measurement is about per cent level at CEPC. In this work, we investigate both O(α) weak correction and the O(ααs) mixed electroweak-QCD corrections for this channel,appropriately taking into account the effect of finite Z^0 width. The μ^+μ^-invariant mass spectrum is also predicted.The mixed electroweak-QCD correction turns out to reach 1.5% of the Born-order result, and thereby must be included in future confrontation with the data. We also observe that, after including higher-order corrections, the simplified prediction for the integrated cross section employing the narrow-width-approximation may deviate from our full result by a few per cents.

e^(+)e^(−)γ production at photon-photon colliders at complete electroweak NLO accuracy

We present the NLO electroweak radiative corrections to the e^(+)e^(−)γ production in γγ collision,which is an ideal channel for calibrating the beam luminosity of a Photon Linear Collider.We analyze the dependence of the total cross section on the beam colliding energy,and then investigate the kinematic distributions of final particles at various initial photon beam polarizations at EW NLO accuracy.The numerical results indicate that the EW relative corrections to the total cross section are non-negligible and become increasingly significant as the increase of the beam colliding energy,even can exceed -10% in the J=2 γγ collision at √s=1 TeV.Such EW corrections are very important and should be taken into consideration in precision theoretical and experimental studies at high-energy γγ colliders.

B→X_(s)γin BLMSSM

Applying the effective Lagrangian method,we study the flavor changing neutral current process b→sγwithin the minimal supersymmetric extension of the Standard Model,where baryon and lepton numbers are local gauge symmetries.Constraints on the parameters are investigated numerically with the experimental data for the branching ratioof B→X_(s)γAdditionally,we present the corrections to direct CP-violation in B→X_(s)γand time-de-pendent CP-asymmetry in B→K*γ.With appropriate assumptions on the parameters,we find the direct CP-viola-tion Acp is very small,while one-loop contributions to S K*γcan be significant.