Cross section and Higgs mass measurement with Higgsstrahlung at the CEPC

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 Ge V. The CEPC will accumulate an integrated luminosity of 5 ab-1over ten years of operation, producing one million Higgs bosons via the Higgsstrahlung and vector boson fusion processes. This sample allows a percent or even sub-percent level determination of the Higgs boson couplings. With GEANT4-based full simulation and a dedicated fast simulation tool, we have evaluated the statistical precisions of the Higgstrahlung cross section σZH and the Higgs mass m H measurement at the CEPC in the Z →μ~＋μ^-channel. The statistical precision of σZH（m_H） measurement could reach 0.97%（6.9 MeV） in the model-independent analysis which uses only the information from Z boson decays. For the standard model Higgs boson, the m H precision could be improved to 5.4 Me V by including the information from Higgs decays. The impact of the TPC size on these measurements is investigated. In addition, we studied the prospect of measuring the Higgs boson decaying into invisible final states at the CEPC. With the Standard Model ZH production rate, the upper limit of B（H → inv.） could reach 1.2% at 95% confidence level.

θ_(13) and the Higgs Mass from High Scale Supersymmetry

In the framework in which supersymmetry is used for understanding fermion masses rather than stabilizing the electroweak scale, we elaborate on the phenomenological analysis for the neutrino physics. A relatively large sin θ13= 0.13 is naturally obtained. The model further predicts vanishingly small CP violation in neutrino oscillations. While the high scale supersymmetry generically results in a Higgs mass of about 141 GeV, our model reduces this mass to 126 CeV via introducing SU（2）L triplet fields which make the electroweak vacuum metastable （with a safe lifetime） and also contribute to neutrino masses.

Interference effects on Higgs mass measurement in e^＋e^-→H(γγ)Z at CEPC

A high luminosity Circular Electron Positron Collider（CEPC） as a Higgs Factory will be helpful for precision measurements of the Higgs mass. The signal-background interference effect is carefully studied for the Higgs diphoton decay mode in associated Z boson production at future e^＋e^-colliders at energy 246 GeV. The mass shifts go up from about 20 MeV to 50 MeV for the experimental mass resolution ranging from 0.8 GeV to 2 GeV.

On a Singular Solution in Higgs Field （Ⅲ）： Condensates and Representation of Certain f0 Mesons＇ Masses

Recently the mass and the basic structure of SM Higgs boson （H^0） have been discussed by the author with obtaining asymptotic solution for the equation of motion of nonlinear Klein-Gordon type partial differential equation. In this paper, we will treat with above in mind： masses of glueball （GB） of ground state and of certain fo mesons, ur, Higgs boson （ur-H^0） which will consist of a number of GBs and/or fo above for respective fullerene structure, a representation of these fo mesons＇ masses by masses of n octet and GB, and transformation of ur-H^0 into H^0.

A comparison of direct and indirect determinations of the masses of the Higgs Boson and the top quark

The indirect estimation of the Higgs Boson mass from electroweak radiative corrections within the Standard Model is compared with the directly measured value obtained by the ATLAS and CMS Collaborations at the CERN LHC collider. Treating the direct measurement of m_H as input, the Standard Model indirect estimation of the top-quark mass is also obtained and compared with its directly measured value. A model-independent analysis finds an indirect value of m_H of ■70 GeV, below the directly measured value of 125.7±0.4 GeV and an indirect value：m_t = 177.3±1.0 GeV, above the directly measured value： 173.21±0.87 GeV. A goodness-of-fit test to the Standard Model using all Z-pole observables and mW has a χ~2 probability of ■2%. The reason why probability values about a factor of ten larger than this, and indirect estimates of m H about 30 GeV higher, have been obtained in recent global fits to the same data is recalled.

Discovery of the Higgs boson by the ATLAS and CMS experiments at the LHC

The Standard Model （SM） Higgs boson was predicted by theorists in the 1960s during the development of the electroweak theory. Prior to the startup of the CERN Large Hadron Collider （LHC）, experimental searches found no evidence of the Higgs boson. In July 2012, the ATLAS and CMS experiments at the LHC reported the discovery of a new bosun in their searches for the SM Higgs boson. Subsequent experimental studies have revealed the spin-0 nature of this new boson and found its couplings to SM particles consistent to those of a Higgs boson. These measurements confirmed the newly discovered boson is indeed a Higgs bosun. More measurements will be performed to compare the properties of the Higgs boson with the SM predictions.

Type 1 2HDM as Effective Theory of Supersymmetry

It is generally believed that the low energy effective theory of the minimal supersymmetric standard model is the type 2 two Higgs doublet model. We will show that the type 1 two Higge doublet model can also be as the effective of supersymmetry in a specific ease with high scale supersymmetry breaking and gauge mediation. If the other electroweak doublet obtain the vacuum expectation value after the electroweak symmetry breaking, the Higgs spectrum is quite different. A remarkable feature is that the physical Higgs boson mass can be 125 GeV unlike in the ordinary models with high scale supersymmetry in which the Higgs mass is generally around 140 GeV.