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تسجيل مستخدم جديدMeasuring BR($h to tau ^+ tau ^-$) at the ILC: a full simulation study
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We evaluate the expected measurement accuracy of the branching ratio of the Standard Model Higgs boson decaying into tau pairs at the ILC with a full simulation of the ILD detector concept. We assume a Higgs mass of 125 GeV, a branching ratio of BR($h to tau ^+ tau ^-$) = 6.32%, a beam polarization of electron (positron) of -0.8(+0.3), and an integrated luminosity of 250 fb$^{-1}$. The Higgs-strahlung process $e^+ e^- to Zh$ with $Z to qoverline{q}$ is analyzed. We estimate the measurement accuracy of the branching ratio $Delta (sigma times mathrm{BR}) / (sigma times mathrm{BR})$ to be 3.4% with using a multivariate analysis technique.
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We evaluate the expected measurement accuracy of the branching ratio of the Standard Model Higgs boson decaying into tau lepton pairs $h to tau ^+ tau ^-$ at the ILC with a center-of-mass energy of $sqrt{s} = 500$ GeV with a full simulation of the IL
D detector. We assume a Higgs mass of $M_h = 125$ GeV, a branching ratio of $mathrm{BR}(h to tau ^+ tau ^-) = 6.32 %$, beam polarizations of $P(e^+, e^-) = (-0.8,+0.3)$, and an integrated luminosity of $int L dt = 500 mathrm{fb^{-1}}$. The Higgs-strahlung process $e^+ e^- to Zh$ with $Z to q overline{q}$ and the $WW$-fusion process $e^+ e^- to u overline{ u} h$ are expected to be the most sensitive channels at $sqrt{s} = 500$ GeV. Using a multivariate analysis technique, we estimate the expected relative measurement accuracy of the branching ratio $Delta(sigma cdot mathrm{BR}) / (sigma cdot mathrm{BR})$ to be 4.7% and 7.4% for the $q overline{q} h$ and $ u overline{ u} h$ final states, respectively. The results are cross-checked using a cut-based analysis.
In the Standard Model, the Higgs boson is a CP even state with CP conserving couplings; any deviations from this would be a sign of new physics. These CP properties can be probed by measuring Higgs decays to tau lepton pairs: the transverse correlati
on between the tau spins depends on CP. This paper develops such an analysis, using full simulation of signal and background events in the International Large Detector concept for the International Linear Collider. We consider Higgs-strahlung events e+ e- -> Z H) in which the Z boson decays to electrons, muons, or hadrons, and the Higgs boson decays to $tau$ leptons, which then decay either to (pi+ nu) or (pi+ pi0 nu). Assuming 2 ab^{-1} of integrated luminosity at a center-of-mass energy of 250~GeV, the mixing angle psi_CP between even and odd CP components of the tau pair from Higgs boson decays can be measured to a precision of 75~mrad (4.3 deg).
We evaluate the measurement accuracy of the branching ratio of $h to tau ^+ tau ^-$ at $sqrt{s} = 250$ GeV and 500 GeV at the ILC with the ILD detector simulation. For the $sqrt{s} = 250$ GeV, we assume the Higgs mass of $M_h = 120$ GeV, branching ra
tio of $mathrm{Br}(h to tau ^+ tau ^-) = 8.0 %$, beam polarization of $P(e^-, e^+) = (-0.8, +0.3)$, and integrated luminosity of $int L dt = 250 mathrm{fb ^{-1}}$. The Higgs-strahlung process $e^+ e^- to Zh$ with $Z to e^+ e^-$, $Z to mu ^+ mu ^-$, $Z to qbar{q}$ mode are analyzed. The measurement accuracy is calculated to be $Delta (sigma cdot mathrm{Br}) / (sigma cdot mathrm{Br}) = 3.5 %$. The scaled result to $M_h = 125$ GeV is estimated to be $4.2 %$. For the $sqrt{s} = 500$ GeV, we assume the Higgs mass of $M_h = 125$ GeV, branching ratio of $mathrm{Br}(h to tau ^+ tau ^-) = 6.32 %$, beam polarization of $P(e^-, e^+) = (-0.8, +0.3)$, and integrated luminosity of $int L dt = 500 mathrm{fb ^{-1}}$. The Higgs-strahlung process $e^+ e^- to Zh$ with $Z to qbar{q}$ mode and $WW$-fusion process $e^+ e^- to u_e bar{ u_e} h$ are analyzed. The measurement accuracy is calculated to be $Delta (sigma cdot mathrm{Br}) / (sigma cdot mathrm{Br}) = 5.7 %$ for Higgs-strahlung with $Z to qbar{q}$ and $7.5 %$ for $WW$-fusion.
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We evaluate the measurement precision of the production cross section times the branching ratio of the Higgs boson decaying into tau lepton pairs at the International Linear Collider (ILC). We analyze various final states associated with the main pro
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