Top Higgs Yukawa Coupling Analysis from e+e- -> ttH -> bW bW bb
  Electroweak symmetry breaking and the origin of mass of fermion and boson are fundamental questions to understand particle physics. The essential piece of this symmetry breaking, the Higgs boson, is the most probable particle to be discovered at the Large Hadron Collider (LHC). If one, or more, Higgs particles are discovered, precise measurements of all the properties of this Higgs will be very important including the measurement of Yukawa couplings of the fermions to the Higgs. We present a study of e+e- -> ttH at a linear collider, with the aim of making a direct measurement of the the top-Higgs coupling, g(ttH) using the semi-leptonic final state and M_H of 120 GeV. We show that the top-Higgs coupling at the center of mass energy 500 GeV, can be measured with an accuracy of better than 28%. 
Hajrah Tabassam and Victoria Martin
hep-ex