Taikan Suehara, acfasim-j meeting, 2008/04/23 page 1

Tau study updatesTau study updates(A(Apolpol etc.) etc.)

Taikan Suehara

Taikan Suehara, acfasim-j meeting, 2008/04/23 page 2

e+e- →τ+τ-e+e- →τ+τ-Processes (e+e-)

√S(GeV)

Observables

Comments

ZH, ZHe+e-X, 250 , mH mH=120GeV, test materials and ID

X 250 , mH mH=120GeV, test P/P

ZH, Hcc, Z 250 Br(Hcc) Test heavy flavour tagging and anti-tagging of light quarks and gluon

, Zqq 250 Br(Hqq) Same as above in multi-jet env.

Z* 500 AFB, Pol( Test 0 reconstruction and rec. aspects of PFA

tt, tbW, Wqq’ 500 AFB, mtop Test b-tagging and PFA in multi-jet events. mtop=175GeV

500 m Point 5 of Table 1 of BP report.W/Z separation by PFA

Taikan Suehara, acfasim-j meeting, 2008/04/23 page 3

TaJet vs. Durham-ycutTaJet 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 bestperformance inenergy estimationof tau-missing

• Despite many aspectsto be improved,I adopt TaJet for current analyses.

Ycut 1+1jets(12500 total) # of jets MC - Reco

energy [GeV]0.00001 8456 2.659 15.030.00002 8723 2.418 11.020.00005 8945 2.209 8.8940.0001 8992 2.115 8.5540.0002 8993 2.043 8.6240.0005 8917 1.97 9.0110.001 8814 1.918 9.4860.002 8662 1.87 9.9350.005 8350 1.803 10.180.01 7977 1.745 10.67

TaJ et 9425 1.91 8.145

Taikan Suehara, acfasim-j meeting, 2008/04/23 page 4

Pol. analysis using Pol. analysis using ->-> channel 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 re

st frame using MC info• MC/Reco direction is origined by flying dire

ction• Check angular information

Taikan Suehara, acfasim-j meeting, 2008/04/23 page 5

coscos ( () (same as last week)) (same as last week)

Taikan Suehara, acfasim-j meeting, 2008/04/23 page 6

Angular distribution (lab. Frame, Angular distribution (lab. Frame, MC 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

Taikan Suehara, acfasim-j meeting, 2008/04/23 page 7

Angular distribution (Angular distribution (-rest frame, -rest frame, MC)MC)

E ~ 1/2m : Lorentz tr. OK!

: isotropic

: isotropicNo difference between+ and - observed.

No polarization ??

Taikan Suehara, acfasim-j meeting, 2008/04/23 page 8

SummarySummary

• 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 ??