WW benchmark analysis: Progress report

Ron Cassell, Tim Barklow8/4/11

1

Event Sample

• Start with 10000 each w34974, w34975 (uddu events, alpha=0, 100% polarization)

• End with 315 + 618 full energy WW and ZZ events.

• 933 evts reduced to 901 by reconstruction cuts.

• Where do they go?

2

Event accountingw34974 Generated Eevt>995. cosΘmx<.97 cosΘmx<.90

WW 7808 1994 506 308

ZZ 127 40 10 7

uDdU 1968

γZ 90

unknown 7

w34975 Generated Eevt>995. cosΘmx<.97 cosΘmx<.90

WW 1890 376 373 357

ZZ 4628 1229 401 261

uDdU 527

γZ 2935

unknown 20

3

“Perfect” reconstruction• Find pdg94 particles. If n != 2, fail.• Find parent quarks. If n != 2, only use quarks with

1 daughter. If n still != 2, fail.• Trace generator final state particles to pdg94.• Boost quarks and fs particles to pdg94 system,

then attach fs particles to nearest q.• Jet 0 is max E jet in dijet with max cos(Θ), jet 1

partner, jet 2 maxE in other dijet, jet 3 partner• Should be no difference in jet 0,2 distributions or

jet 1,3 distributions

4

Jet clustering from PFOs

• Hemisphere cut: Use thrust axis, separate particles by dot product >< 0.

• For each hemisphere: Boost to cm, find thrust axis, separate into hemisphere.

• If # particles in any of the 4 jets < 2, fail.• Match to “perfect” with chisq.

5

Jet energy offsets and resolution

6

dE m90 (GeV)

Jet Energy (GeV)0 100 200 300 400 500

-35

-30

-25

-20

-15

-10

-5

0

5

WW1000: Jet energy pedestals

dE/E(rms90)

Jet Energy (GeV)0 100 200 300 400 500

0.04

0.05

0.06

0.07

0.08

0.09

0.10

0.11

WW1000Fixed E qq

Jet Energy resolution

Procedure

• Use the matched jets to find the errors in the 16 variables. (E,β,Θ,φ for each jet)

• Not enough events for meaningful correlations in the covariance matrix, use diagonal for now.

• Constrain ΣE = 1000, ΣPx = ΣPy = ΣPz = 0.• Motivation: Tim’s fast MC study of ZH at 350

GeV

7

jet

jet

E0.3

E

jet

jet

E0.3

E

Reconstructed Mbb 4C Fitted Mbb

0.4

0.5 0.6

0.4

0.5 0.6

e e ZH qqbb

Mbb (GeV) Mbb (GeV) Mbb (GeV) Mbb (GeV)

8

1

350

500

s GeV

L fb

jet

jet

42 MeV

E0.3

E

hM

e e ZH

qqbb

jet

jet

46 MeV

E0.4

E

hM

jet

jet

48 MeV

E0.5

E

hM

jet

jet

50 MeV

E0.6

E

hM

Mbb (GeV) Mbb (GeV)

Mbb (GeV) Mbb (GeV)

9

Prefit results: Energy

10

entries/2 GeV

delta Energy (GeV)-60 -40 -20 0 20 40 60

020406080

100120140160180200220240

Original Recon/LE jet delta Energy Entries : 1802 Mean : 0.27646 Rms : 19.526

gauss amplitude : 156.48±6.111 mean : 0.98274±0.2029 sigma : 8.0574±0.241 χ² : 3.7144

Recon-perfect LE jet energyentries/4 GeV

delta jet energy (GeV)-100 -50 0 50 1000

20

40

60

80

100

120

140

160

180

Original Recon/HE jet delta Energy Entries : 1802 Mean : -9.4062 Rms : 28.060

gauss amplitude : 133.53±4.890 mean : -8.7756±0.5237 sigma : 19.658±0.533 χ² : 3.0654

recon-perfect HE jet energy

Prefit results: Beta

11

entries/.0001

delta Beta-0.004 -0.002 0.000 0.002 0.004

0

50

100

150

200

250

300 Original Recon/HE jet delta Beta Entries : 1802 Mean : -2.9699E-4 Rms : 1.5094E-3

gauss amplitude : 187.65±7.772 mean : -1.0842E-4±9.220E-6 sigma : 3.0525E-4±9.64E-6 χ² : 4.4478

HE jet delta Beta

entries/.001

delta Beta-0.04 -0.02 0.00 0.02 0.04

0

50

100

150

200

250

300Original Recon/LE jet delta Beta Entries : 1802 Mean : -3.1391E-3 Rms : 0.018282

gauss amplitude : 154.79±8.801 mean : -2.0286E-3±1.260E-4 sigma : 3.1054E-3±1.524E-4 χ² : 6.5475

LE jet delta Beta

Prefit results: Theta

12

entries/2mr

delta Theta-0.10 -0.05 0.00 0.05 0.100

50

100

150

200

250

300

350Original Recon/HE jet delta Theta Entries : 1802 Mean : -3.3525E-6 Rms : 0.021391

gauss amplitude : 219.58±9.316 mean : 3.6259E-4±1.4178E-4 sigma : 5.5268E-3±1.868E-4 χ² : 4.5346

HE jet: delta Theta

entries/10mr

delta Theta-0.3 -0.2 -0.1 0.0 0.1 0.2 0.3

0

100

200

300

400

500

600Original Recon/LE jet delta Theta Entries : 1802 Mean : 1.0540E-3 Rms : 0.051611

gauss amplitude : 471.45±21.21 mean : -9.8352E-4±3.2583E-4 sigma : 0.012500±4.580E-4 χ² : 6.3549

LE jet: delta Theta

Prefit results: Phi

13

en tries/5mr

delta Phi-0.15 -0.10 -0.05 0.00 0.05 0.10 0.150

100

200

300

400

500

600

Original Recon/HE jet delta Phi Entries : 1802 Mean : 2.8874E-4 Rms : 0.028195

gauss amplitude : 487.19±19.47 mean : 2.1075E-5±1.6378E-4 sigma : 6.4997E-3±0.000202 χ² : 5.4186

HE jet: delta Phi

entries/10mr

delta Phi-0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 0.4

0

50

100

150

200

250

300

350

400

450

500Original Recon/LE jet delta Phi Entries : 1802 Mean : -3.1945E-3 Rms : 0.067029

gauss amplitude : 453.23±12.8 mean : -7.1323E-4±3.3798E-4 sigma : 0.012975±0.000142 χ² : 5.5149

LE jet: delta Phi

Prefit results: Mass

14

entries/1 GeV

delta Mass (GeV)-30 -20 -10 0 10 20 30

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

Original Recon/Dijet/Recon-Perfect/dDijet M Entries : 1802 Mean : 2.0673 Rms : 6.9359

gauss amplitude : 113.15±3.821 mean : 1.9154±0.1507 sigma : 6.0400±0.143 χ² : 1.6616

Reconstructed - Generated dijet Mass

Observations

• Offset in Energy expected.• Offset in Beta unexpected.• Offset in Mass opposite to what I expected.

15

4C fit results

16

entries/0.2 GeV

(Fit-Generated) dijet Momentum (GeV)-4 -3 -2 -1 0 1 2 3 4

0

20

40

60

80

100

120

140

160

180

200

Original Recon FitD0/Dijet/Recon-Perfect/dDijet P Entries : 1802 Mean : -0.088457 Rms : 1.0859

gauss amplitude : 150.92±5.052 mean : -0.17692±0.02216 sigma : 0.89385±0.0206 χ² : 2.8588

4CFit: delta dijet Momentum

entries/0.1 GeV

(Fit-Generated) dijet Energy (GeV)-4 -2 0 2 4 6

0

20

40

60

80

100

120

140

160

180

200

Original Recon FitD0/Dijet/Recon-Perfect/dDijet E Entries : 1802 Mean : 0.55217 Rms : 1.1678

gauss amplitude : 144.00±5.015 mean : 0.43481±0.02529 sigma : 0.91193±0.0224 χ² : 3.5472

4CFit: delta dijet Energy

4C fit results

17

entries/1 GeV

(Fit-Generated) dijet Mass (GeV)-40 -30 -20 -10 0 10 20 30

0

20

40

60

80

100

120

140

160

180

200

Original Recon FitD0/Dijet/Recon-Perfect/dDijet M Entries : 1802 Mean : 3.5614 Rms : 5.9782

gauss amplitude : 144.97±5.177 mean : 3.3153±0.1270 sigma : 4.5212±0.117 χ² : 3.0733

4CFit: delta dijet Mass

Comments

• Not the improvement we expected• Trying to understand:• Mass offset, beta offset.• If mass errors make sense.• To check fits, input correct beta values.

18

Fit check

19

entries/1 GeV

delta Mass (GeV)-40 -20 0 20 40 60

0

50

100

150

200

250

300

Original Recon FitD2/Dijet/Recon-Perfect/dDijet M Entries : 1802 Mean : 0.89276 Rms : 5.8289

gauss amplitude : 222.95±8.411 mean : 0.59359±0.07219 sigma : 2.8959±0.0822 χ² : 3.4637

4CFit:correct beta input: delta Mass

Mass error checks• Can write out the full error propagation for dijet

mass.• If we use mean values of the perfect

distributions, and gaussian fits for the deltas, substituting these values gives ΔM/M = 7.4%. We measure 7.35%.

• The breakdown: from ΔE: 5.4%, Δangles: 3.4%, Δβ: 3.7%

• The constraints eliminate the ΔE error, but broaden slightly the other errors.

• Should get to 5% after fit, but see 5.4%.

20

Next steps

• 100k of each polarization generated, need to process.

• Should allow full covariance matrix calculation• Need to understand “low β” in reconstruction.

21

Backups

22

Jet Energy

23

Jet Energy (GeV)0 100 200 300 400 500

0

20

40

60

80

100

120

140

160

180

HE jet EnergyLE jet Energy LE jet Energy

Entries : 1802 Mean : 140.45 Rms : 65.556

HE jet Energy Entries : 1802 Mean : 358.99 Rms : 65.599

Perfect Recon: Jet Energy

Jet Energy (GeV)0 100 200 300 400 500

0

20

40

60

80

100

120

140

160

180

HE jet EnergyLE jet Energy

LE jet Energy Entries : 1802 Mean : 140.72 Rms : 65.266

HE jet Energy Entries : 1802 Mean : 349.59 Rms : 62.505

Original Recon: Jet Energy

Jet Beta

24

entries/.0005

Beta0.980 0.985 0.990 0.995 1.0000

100

200

300

400

500

600

700

Entries : 1802 Mean : 0.99876 Rms : 1.7389E-3

Perfect Recon/HE jet Beta

entries/.005

Beta0.6 0.7 0.8 0.9 1.0

0

100

200

300

400

500

600

700

800

900

Entries : 1802 Mean : 0.98114 Rms : 0.041318

Perfect Recon/LE jet Beta

25

65 70 75 80 85 90 95 100 10565

70

75

80

85

90

95

100

105

Original Recon Fit0/Dijet/Recon/Dijet M2 vs M1

26

75 80 85 90 95

74

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94

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100

Original Recon Fit0/Dijet/Perfect/Dijet M2 vs M1