Precise measurement of Higgs boson couplings is an important task for International Linear Collider (ILC) experiments and will facilitate the understanding of the particle mass generation mechanism. In this study, the measurement accuracies of the
Higgs boson branching fractions to the $b$ and $c$ quarks and gluons, $Delta Br(Hto bbar{b},sim cbar{c},sim gg)/Br$, were evaluated with the full International Large Detector model (texttt{ILD_00}) for the Higgs mass of 120 GeV at the center-of-mass (CM) energies of 250 and 350 GeV using neutrino, hadronic and leptonic channels and assuming an integrated luminosity of $250 {rm fb^{-1}}$, and an electron (positron) beam polarization of -80% (+30%). We obtained the following measurement accuracies of the Higgs cross section times branching fraction ($Delta (sigma cdot Br)/sigma cdot Br$) for decay of the Higgs into $bbar{b}$, $cbar{c}$, and $gg$; as 1.0%, 6.9%, and 8.5% at a CM energy of 250 GeV and 1.0%, 6.2%, and 7.3% at 350 GeV, respectively. After the measurement accuracy of the cross section ($Deltasigma/sigma$) was corrected using the results of studies at 250 GeV and their extrapolation to 350 GeV, the derived measurement accuracies of the branching fractions ($Delta Br/Br$) to $bbar{b}$, $cbar{c}$, and gg were 2.7%, 7.3%, and 8.9% at a CM energy of 250 GeV and 3.6%, 7.2%, and 8.1% at 350 GeV, respectively.
Precise measurement of the Higgs boson properties are important issues for the International Linear Collider (ILC) project to understand the particles mass generation mechanism which strongly related to the coupling with the Higgs boson. Large Hadron
Collider (LHC) experiments exclude the large area of the predicted Higgs mass region and their results indicate that Higgs boson mass will be light. Even if LHC discovers the Higgs like particle by the end of 2012, Higgs will be identified by the high precision measurement of the Higgs boson properties in ILC and also Higgs measurement verifies the correctness of standard model (SM) or gives some hints toward its beyond. In this study, we evaluate the measurement accuracies of Higgs branching fraction to the H->bb, cc and gg at the center-of-mass energy of 250 and 350 GeV.
Precise measurement of the Higgs boson properties is an important issue of the International Linear Collider (ILC) experiment to verify the particles mass generation mechanism that the coupling strength between the Higgs boson and the fermions or vec
tor bosons are proportional to the mass of each particle. Thus the measurement of the branching ratio of the Higgs boson an important issue to understand the mass of each particle. In this analysis, measurement accuracy of the Higgs boson branching ratio in the ZH->qqH hadronic decay mode was studied with the cut-based analysis in Higgs mass of M_{H}=120 GeV at the center-of-mass energy of sqrt{s}=250 GeV with the ILD detector model. From the analysis, we estimate the measurement accuracy of the relative Higgs boson branching ratio of BR(H->cc)$ to BR(H->bb) as 13.68%.
Precise measurement of the Higgs boson properties is an important issue of the International Linear Collider (ILC) experiment. We studied the accuracy of the Higgs mass reconstruction in the ZH->qqH multi-jet process with the Higgs mass of MH = 120 G
eV at sqrt(s) = 250 GeV with the ILD detector model. In this study, we obtained the reconstructed Higgs mass of M_H = 120.79 +- 0.089 GeV and 5.3% measurement accuracy of the cross-section for ZH->qqbb with the integrated luminosity of L=250 fb^{-1} data samples.
