Electron and Positron Polarizations for ttH Final State

1
Electron and Positron Polarizations for ttH
Final State

• Akimasa Ishikawa
• (Saga University)

2
Polarization

• Electron and positron polarizations are one of
  the key issues for LC physics since they increase
  the signal s or suppress BG s.
• There are two effect
• Increase spin 1 combinations
• Coupling to SU(2)L gauge boson
• EM interaction respects Parity but SU(2)L does
  not.
• Coupling to Z boson is
• For electron positron case, the coupling is not
  so different for left handed or right handed pol.
  Since the Weiburg angle is close to quarter. But
  top case, left handed gives larger cross section.

e
e-
e
e-
0.5
0.25
0.5
0.5
0.5
1.0
1.0
1.0
0.25
P(0,0)
P(-1,1)
3
Polarization for ttH

• I have calculated the cross section as a function
  of Ecm for P(-1.0, 0.0), P(1.0, 0.0) and
  P(-0.8, 0.6) with M_H 120 GeV and M_t
  170.9GeV

4
Summary and Plan

• Electron and Positron Polarizations are veru
  useful to pursue LC physics.
• Left handed polarization gives about 2 times
  large cross section than unpolarized case.
• s 1.1fb with Mh120GeV and Mt170.9GeV
• Prepare the generator for H?WW, ZZ
• Start analysis