1. Taikan Suehara, acfasim-j meeting, 2008/04/23 page 1 Tau study updates (A pol etc.) Taikan Suehara

2. Taikan Suehara, acfasim-j meeting, 2008/04/23 page 2 e+e- →τ+τ- Processes (e + e -  ) √S (GeV) ObservablesComments ZH, ZH  e + e - X,250 , m H m H =120GeV, test materials and  ID      X250 , m H m H =120GeV, test  P/P ZH, H  cc, Z  250Br(H  cc)Test heavy flavour tagging and anti- tagging of light quarks and gluon, Z  qq250Br(H  qq)Same as above in multi-jet env. Z*      500  A FB, Pol(  Test  0 reconstruction and  rec. aspects of PFA tt, t  bW, W  qq’500  A FB, m top Test b-tagging and PFA in multi-jet events. m top =175GeV           500  m  Point 5 of Table 1 of BP report. W/Z separation by PFA

3. Taikan Suehara, acfasim-j meeting, 2008/04/23 page 3 TaJet vs. Durham-ycut Compare original tau jet finder (TaJet) with “durhamycut” in Satoru jet finder (durhamycut is the only non-njet-fixed jet finder in SatoruJet except “manual” tuning mode) TaJet gives the best performance in energy estimation of tau-missing Despite many aspects to be improved, I adopt TaJet for current analyses.

4. Taikan Suehara, acfasim-j meeting, 2008/04/23 page 4 Pol. analysis using  ->  channel glddec07 tautau500 data (12500 events) 1432  + and 1429  - events (11.4%) (selected by MC info) 2246 1+1 jet events (8.98%) by TaJet → recorded into root file for analysis MC/Reco  4-momentum is converted to  rest frame using MC  info MC/Reco direction is origined by  flying direction Check angular information

5. Taikan Suehara, acfasim-j meeting, 2008/04/23 page 5 cos  (  ) (same as last week)

6. Taikan Suehara, acfasim-j meeting, 2008/04/23 page 6 Angular distribution (lab. Frame, MC  ) Frame rotation seems to be worked (z is the tau direction, x is on the plane of beam axis and tau flying axis) Concentrated to tau axis (because of high  factor) No dependence observed on 

7. Taikan Suehara, acfasim-j meeting, 2008/04/23 page 7 Angular distribution (  -rest frame, MC) E  ~ 1/2m  : Lorentz tr. OK!  : isotropic  : isotropic No difference between  + and  - observed. No polarization ??

8. Taikan Suehara, acfasim-j meeting, 2008/04/23 page 8Summary TaJet and Durhamycut was compared. Currently TaJet gives better performance. First polarization analysis was performed. (Currently many parts use MC truth.) For  ->  mode, no asymmetry observed in  angular distribution In glddec07 events polarization of taus is not implemented ??