Download ppt - Mass window and bining optimization

22/01/2001 - ALEPH Week

• Mass window and bining optimization

• Complete results for all the energies using the qq channel

• Check of the reproducibility

• Fragmentation systematic in the qq channel

W Mass measurement in the qq channel

W Mass measurement in the qq channel

D. BOUMEDIENE

CEA Saclay

22/01/2001 - ALEPH Week

Bining

SG + BckMass window

MW (Expected) MeV/c2

72-9055x4 + 5x2

315 3

50x4 + 5x2

316 3

70-9760x4 + 6x2

311 3

70x4 + 8x2

308 4

70x6 + 8x2

304 4

Mass window and biningoptimization

Mass window and biningoptimization

s = 200 GeV

Large mass window

More luminosity

but additional Background (ZZ)

22/01/2001 - ALEPH Week

Bining

SG + BckMass window

MW (Exp.) MeV/c2

70-97

µvqq

50x5x5 + 2x1x1 221 2

70-97

evqq234 2

50x5x3 + 2x1x1

s = 200 GeV

Possible on e,µqq ?Possible on e,µqq ?

22/01/2001 - ALEPH Week

Results @ 196 GeVResults @ 196 GeV

22/01/2001 - ALEPH Week

Mass plot @ 196 GeVMass plot @ 196 GeV

22/01/2001 - ALEPH Week


22/01/2001 - ALEPH Week

Mass plot @ 200 GeVMass plot @ 200 GeV

Fit to the data @ 192 GeVFit to the data @ 192 GeV

MW= 80.755+ 0.443- 0.421

22/01/2001 - ALEPH Week


22/01/2001 - ALEPH Week

Results @ <205> GeVResults @ <205> GeV

22/01/2001 - ALEPH Week

Mass plot @ <205> GeVMass plot @ <205> GeV

nn cut optimizatio

n

205

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Results @ <207> GeVResults @ <207> GeV

22/01/2001 - ALEPH Week

s(GeV)

Observedresolution(MeV/c2)

Expectedresolution(MeV/c2)

Resolutionnormalized to

200 pb-1

189 208 212 1199 1

192 432 --- (165)

196 314 316 5200 2

303 304 4200 2

200275 309 4

202 2

202 434 482 9215 4

328 343 2209 1

205369 331 2

202 1

207

Stability and reproducibility checks in the qq channel

Stability and reproducibility checks in the qq channel

test cut nn

nn test

22/01/2001 - ALEPH Week

Fragmentation systematicin qq channel

Fragmentation systematicin qq channel

With the half of the MC stat.:

MW frag. = 12 ± 7 MeV/c2

22/01/2001 - ALEPH Week