We report on the feasibility of measuring the top Yukawa coupling in the process: $e^+e^-to tbar{t}H$. This measurement is crucial to test the mass generation mechanism for matter particles. Since the cross section for this process attains its maximu
m around $sqrt{s}=700 $GeV, most of the past studies were done assuming this energy region. It has been pointed out, however, that the QCD threshold correction enhances the cross section significantly and might enable its measurement at $sqrt{s}=500 $GeV, which will be accessible already in the first phase of the ILC project. We have implemented this threshold enhancement into our $tbar{t}H$ event generator and carried out Monte Carlo simulations. Our results show that $tbar{t}H$ events can be observed with a significance of $4.1,sigma$ with no beam polarization and $5.4 sigma$ with the $e^-$ and $e^+$ beam polarization combination: $(-0.8,+0.3)$.
In Japan, China and Russia, there are several test beam lines available or will become available in near future. Those are open for users who need electron, muon and charged pion beams with energies of 1-50 GeV for any tests of small-size detectors.
In this manuscript I present a current status of those test beam facilities in the Asian region.
The scintillator-strip electromagnetic calorimeter (ScECAL) is one of the calorimeter technologies which can achieve fine granularity required for the particle flow algorithm. Second prototype of the ScECAL has been built and tested with analog hadro
n calorimeter (AHCAL) and tail catcher (TCMT) in September 2008 at Fermilab meson test beam facility. Data are taken with 1 to 32 GeV of electron, pion and muon beams to evaluate all the necessary performances of the ScECAL, AHCAL and TCMT system. This manuscript describes overview of the beam test and very preliminary results focusing on the ScECAL part.
