|Budget Amount *help
¥2,400,000 (Direct Cost : ¥2,400,000)
Fiscal Year 1991 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1990 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1989 : ¥1,400,000 (Direct Cost : ¥1,400,000)
In 1989 we calclulated a ratio of the signal(S) and background (BG) of the following processes :
(S) : e^-e^+-> Z -> tau tau^^- + H -> tau + b b^^- jets, (1)
(BG) : e^-e^+-> Z, gamma -> f f^^- -> tau tau^^- + q q^^- jets + X. (2)
Here tau, b, f and q denote the lepton, beauty quark, fermion and quark, respectively. We have shown that the standard Higgs particle with the mass range, 20 < M_H < 30 GeV, can be detectable at M_Z-pole.
In 1990, based on our previous results, we proposed a precise test of the standard theory at TRISTAN energy (*s = 60 GeV). [In other words, the energy distribution of the leptons in the BG can be used for a test of the standard theory). Secondly we calculated the ratio of the S to BG at LEP II and JLC (<square root>s = 300 GeV).
In 1991 we calculated the following background (BG2) which mainly contributes at LEP II
(BG2) : e^-e^+-> V, Z -> V, tau tau^^- (V = Z, gamma). (3)
Taking into account various physical conditions, we found that the signal of the process (1), the standard Higgs particle with M_H < 85 GeV, can be detectable in the region of E_- > 70 GeV at (]SY.sqroot. ]). ss = 2M_Z in the energy distribution of lepton dsigma/dE_-.