Higgs branching ratios study for DBD

ILC physics WG general meetingJan. 12 2013

H. Ono (NDU)

Jan. 12 2013 ILC physics WG general meeting 1

• Detailed Baseline Design document publication is on-going

• Physics chapter– Demonstrate performance of Higgs measurement in ILC– 250 to 1 TeV with possible decay channels

• Update hWW* analysis at 250 GeV (rightleft beam pol)

• Detector chapter (detector benchmarking process)– vvh @ 1 TeV decaying into bb, cc, gg, WW*– sigma*BRs are evaluated

Higgs BR study in DBD

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Higgs BR study at 1 TeV (DBD)

Jan. 12 2013 ILC physics WG general meeting

Higgs mainly produced via e+e- νeνeh (WW-fusion)hbb, cc, gg (two jets)hWW* (four jets via hadronic decay)hμμ (dilepton)C. Constantino (KEK)

3

Ecm=1 TeVLuminosity: L=1 ab-1 (500 fb-1 both pol.)Beam polarization P(e-, e+)=(0.8, 0.2)γγhadron BG is overlaid (4 event/BX)

Larger cross section than Zh@250 GeVStatistical gain (xsec and luminosity)Measure smaller BR channels

ΥΥhadron background treatment

Jan. 12 2013 ILC physics WG general meeting

Higgs dijet rec. with γγhadron BG

1. Apply kt two jet clustering2. Use only jet associated PFOs3. Reapply flavor tagging and

jet clustering with LCFIPlus

4

Beam related particle (4.1 event/BX) is treated with kt jet clustering (commonly used in hadron collider study)

Jet reconstruction procedure

Optimize R parameter used in kt algorithm

Check Higgs reconstruction and BG reduction with γγ BG overlay

Select R=1.1 for 2 jet reconstruction

Cuts for hbb, cc, gg channel @ 1 TeV

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1. Visible energy: 40 < Evis < 450 GeV2. Transverse momentum: PT>20 GeV3. Longitudinal momentum: |PZ|<400 GeV4. # of PFOs: NPFOs>205. |cosθh|<0.986. Dijet mass: 110<Mh<150 GeV

After all cuts,flavor template fitting is applied

hbb, cc, gg template fitting analysis

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After the cuts, prepare flavor templates of signals and BGs

hbb hcc

hothers SM BGsData

Ndata is fluctuated wit Poisson5,000 times of Toy MC is appliedto evaluate the accuracy of σBR

rxx=σBR/σBRSM(hxx)Ndata=Σrxx*Ntemplate(hxx)+NBG

(rxx is a fitted parameter)

Signal templates

BG templates

hgg

hbb, cc, gg hadronic channel @ 1 TeV

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Flavor template for hbb, cc, gg and others are preparedTemplate fitting is performed to evaluate accuracy of σBR

Higgs mass with B-tagging (hbb)

Fitted rbb, rcc, rgg

L=500 fb-1 and 1 ab-1 P(-0.8, +0.2)

rbbrcc rgg

1. Apply forced four jet clusteringwith kt jet clustering (R=1.1)

2. Apply flavor tag for jet associated particles with LCFIPlus

3. Jet clustering and paring for W1, W2 (W1 is on-shell with J1, J2)

4. Select best candidate with minimizing χ2

hWW* channel @ 1 TeV

Jan. 12 2013 ILC physics WG general meeting

hWW* (one on-shell W) from Higgs decayhWW*qqqq fully hadronic decay channel is considered

h

W1

W2

8

L=500 fb-1, 1 ab-1

(e-,e+)=(-0.8, +0.2)

hWW* background reduction

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Btag sum

Npfos

Remove hbb

Remove leptonic-Log10Y34

On-shell W mass Off-shell W mass

-Log10Y45

Remove di-jets

hWW*4j reconstruction

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Significance=46.2

ΔσBR/σBR = 2.2%

L=500 fb-1

(e-,e+)=(-0.8, +0.2)

Beam polarization effectP(e-,e+)=PL(-0.8, +0.2) and PR(+0.8, -0.2)

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Statistical gain at higher energy Decrease eevvh WW-fusionproduction process

eL(-0.8,+0.2) eR(+0.8,-0.2)

Same cut and strategy are applied for right-handed case eR(+0.8, -0.2)

Summary of Higgs BR study at 1 TeV

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Ecm=1 TeV, L=500 fb-1, and 1 ab-1

(e-, e+)=(-0.8, +0.2), Mh=125 GeV

ΔσBR/σBR

Luminosity 500 fb-1 1ab-1

P(e-, e+) (-0.8, +0.2)

hbb 0.45% 0.33%hcc 4.4% 3.1%hgg 3.2% 2.2%hWW* 2.2% 1.5%

ΔσBR/σBR

Luminosity 500 fb-1 500 fb-1 500L+500R

P(e-,e+) (-0.8,+0.2)

(+0.8, -0.2) Combined

hbb 0.45% 1.6% 0.43%hcc 4.4% 17.3% 4.3%hgg 3.2% 13.8% 3.1%hWW* 2.2% 10.1% 2.1%

Left-handed only Left/Right-handed combined

Left-handed beam polarization run is suitable at 1 TeV for Higgs analysis point of view

hWW* at 250 GeV

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HWW* study @ 250 GeV

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Z

W1

W2

lepton + 4 jet final state

H

4 jet final state

W1

W2

HZ

ZhvvWW*vv+qqqq ZhqqWW*qq+lvqq

Ecm=250 GeV, L=250 fb-1, Mh=120 GeV (LOI samples)

Previous study only concerning right-handed polarizationCheck Left-handed beam polarization caseto keep consistency with other channels P(-0.8, +0.3) @ 250 GeV

1. ZhvvWW*vv+qqqq @ 250 GeV, L=250 fb-1, Mh=120 GeV

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4 jet final state

W1

W2

HZ

1. Apply forced four-jets clustering2. Require one on-shell W and

4 jets consistent with Higgs3. Minimum c2 pair as best candidate

Main backgroundHbb, WW, ZZ

Cut variablesZhvvWW*vv+qqqq

1. 115<Evis<150 GeV (vvh channel)

2. 20<Pt<90 GeV

3. |Pl|<60 GeV

4. 85<Missing mass<150 GeV (Mmiss~MZ)

5. Nchdtrk>20 (4 jet finale state)6. ConeEjet/Ejet<0.9 (Remove isolated leptons)

7. Sum(WjBag)<1.0 (hbb suppression)

8. b-likeness2j<0.45 (hbb suppression)

9. Sum(Y34_j)<10 (hothers suppression)10. 65<Mw1<95 GeV (On-shell W mass)

11. 110<Mh<130 GeV

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Cut variables to suppress BGs

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ConeE<Ejet

Ejet

coneE~Ejet

ConeE

leptonic channel

Cone angle = 5 degree -Log10(Y34) sum for 4j

Btag sum for 4jConeEjet/Ejet

Reconstructed Higgs massZhvvWW*vv+qqqq

Signal significance=8.2ΔσBR/σBR=12.3%

eL(-0.8, +0.3)

Signal significance=10.6ΔσBR/σBR=9.5%

eR(+0.8, -0.3)

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Ecm=250 GeV, L=250 fb-1, Mh=120 GeV

Higgs mass (GeV) Higgs mass (GeV)

2. ZhqqWW*qq+lvqq@ 250 GeV, L=250 fb-1, Mh=120 GeV

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Z

W1

W2

lepton + 4 jet final state

H

1. Find one-isolated lepton1. Isolated track finding2. lepton identification

2. Remove one-isolated lepton3. Four-jets clustering to remaining s

One on-shell W (Wlv, Wqq)Mjj~MZ and M4j~MH

4. Minimum c2 combination (c2lv, c2

qq)

qH=qww=qcm-qz

qmis=qcm-qall

qWlv = qmis+ql

HWW*lvqq reconstruction

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HWWlvqq HWWqqqq HOthers

MWlv

MW

jj

Reconstruct as one-isolated lepton+4 jetMass correlation of Zqq + WWlvqq, Mwlv, Mwqq

(MWlv=M(qlep+qmis))

Require Wlv on-shell to suppress hothers and qqqq backgrounds

hWW*lvqq selection (Require Wlv is on-shell)65<Mwlv<110 GeV, 10<Mwqq<50 GeV

1. 10 < PT < 80 GeV2. |PZ| < 50 GeV3. NPFO > 60 (Remove leptonic channel)4. Thrust < 0.855. Thrust_minor > 0.16. -Log10Y34 < 2.57. χ2

W<60 (Suppress WWvlqq BGs)8. 65 < Ewlv < 110 GeV (Suppres vlqq BGs)9. 80 < MZ < 100 GeV (Suppress WW BGs)10.Missing mass <50 GeV (vlqq and qq suppress)11. 105<Mh<140 GeV

ZhqqWW*qq+vlqq@ 250 GeV, L=250 fb-1, Mh=120 GeV

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Reconstructed Higgs mass distributionZhqqWW*qq+vlqq

Signal significance=9.4ΔσBR/σBR=10.7%

eL(-0.8, +0.3)

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eR(+0.8, -0.3)

Signal significance=10.6ΔσBR/σBR=9.6%

Higgs mass (GeV) Higgs mass (GeV)

Ecm=250 GeV, L=250 fb-1, Mh=120 GeV

hWW* @250 GeV summary

　 eL(-0.8,+0.3)ZhvvWWvv+4j　

ZhqqWWqq+lvqq Combined

Significance 8.2 9.4 12.4ΔσBR/σBR 12.3% 10.7% 8.1%

　 eR(+0.8,-0.3)ZhvvWWvv+4j　

ZhqqWWqq+lvqq Combined

Significance 10.6 10.4 14.8ΔσBR/σBR 9.5% 9.6% 6.8%

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hWW* study @ 250 GeV, L=250 fb-1, Mh=120GeVZhvvWW*vv+qqqqZhqqWW*qq+vlqq

Higgs BRs summary table

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Mode ΔσBR/σBREcm 250 GeV 350 GeV 500 GeV 1 TeV

Luminosity 250 fb-1 250 fb-1 500 fb-1 500 fb-1

Mh 120 GeV 120 GeV 120 GeV 125 GeVP(e-, e+) P(-0.8,

+0.3)P(-0.8, +0.3) P(-0.8, +0.3) P(-0.8,

+0.2)

hbb 1.0% 1.0% 0.57% 0.45%hcc 6.9% 6.2% 5.2% 4.4%hgg 8.5% 7.3% 5.0% 3.2%hWW* 8.1% 3.0% 2.2%hττ 4.2%

Current available results are summarized with all full simulationZh or vvh (fusion) is different at the CM energy

• Performance of “Possible BR decays” should be shown to demonstrate the potential of ILC measurement– DBD physics chapter and summary

• vvh @ 1 TeV benchmark study is now on-going– Summarize to LC note

• Several studies should be continue– Different Ecm, Mh=125 GeV– hZZ* (I studied but now pending…) should be done.

Conclusion

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BACKUP

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ZhvvWW*vv+4j eL(-0.8,+0.3) @250 GeV L=250 fb-1

Signal significance=8.2Remaining BGs are hothers and vlqq

　 hWW*4j hother nlqq nnqq llqq nnll qqqq llll qqGen 1,253 18,106 4,114,190 149,979 398,324 1,113,080 4,048,390 762,975 35,353,300

1 1,209 12,882 824,232 90,390 12,872 178,534 1,290 30,303 17,518,5002 1,114 11,852 667,187 81,561 3,109 148,398 52 1,432 25,3823 1,072 11,391 417,939 50,374 2,381 118,547 48 877 9,0184 964 10,509 241,207 46,759 1,711 99,872 38 715 8,5335 880 7,409 85,950 19,832 880 0 38 0 4,4276 783 5,930 20,656 13,545 279 0 37 0 2,8017 760 1,648 19,802 10,364 167 0 30 0 1,1018 755 1,458 19,661 10,171 165 0 30 0 1,0299 676 647 11,677 3,109 118 0 30 0 214

10 595 533 6,219 1,029 100 0 20 0 21111 557 471 3,339 249 54 0 1 0 0Eff 44.5% 2.6% 0.1% 0.2% 0.0% 0.0% 0.0% 0.0% 0.0%

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ZhvvWW*vv+4j eR(+0.8,-0.3)@ 250 GeV L=250 fb-1

　 hWW*4j hother nlqq nnqq llqq nnll qqqq llll qqGen 678 9,956 298,103 63,649 335,756 108,074 378,726 753,964 22,270,700

1 659 7,166 65,711 39,328 9,549 17,000 688 29,766 11,838,8002 616 6,649 53,589 35,464 1,775 13,752 14 1,121 13,2073 602 6,482 31,917 21,277 1,307 9,893 8 637 3,9184 564 6,172 17,685 19,612 953 8,452 8 520 3,7645 516 4,337 6,280 8,144 462 0 7 0 1,5466 464 3,461 1,525 5,558 155 0 7 0 8717 451 967 1,461 4,230 90 0 3 0 3268 446 852 1,451 4,151 89 0 3 0 2829 397 379 862 1,236 66 0 2 0 103

10 348 313 454 360 51 0 2 0 5811 325 281 239 77 29 0 0 0 0Eff 48.0% 2.8% 0.1% 0.1% 0.0% 0.0% 0.0% 0.0% 0.0%

Signal significance=10.6Remaining BGs are hothers and vlqq

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ZhqqWW*qq+vlqq eL(-0.8,+0.3)@ 250 GeV, L=250 fb-1, Mh=120 GeV

Signal significance=9.5

　qqWWqq+vlqq hother nlqq nnqq llqq qqqq nnll llll qq

Gen 3,281 49,226 4,111,390 149,979 380,418 4,048,390 1,110,910 714,946 35,353,300

Sel 1,153 1,507 1,214,800 15,584 24,741 17,495 28,012 36,472 3,383,3001 1,100 1,341 1,080,960 13,145 8,141 2,718 25,994 4,886 161,7162 1,038 1,255 730,075 4,640 6,186 2,228 20,533 3,734 41,3603 775 334 50,554 805 952 1,897 0 0 13,9464 734 307 36,546 641 812 1,803 0 0 3,1005 729 292 34,839 615 766 1,770 0 0 2,9466 662 277 28,133 397 710 1,670 0 0 1,9737 618 227 10,393 122 574 1,523 0 0 1,4808 557 190 6,657 35 430 1,511 0 0 1,4809 411 113 3,041 19 273 850 0 0 642

10 246 18 573 0 32 58 0 0 011 208 11 209 0 24 42 0 0 0

Eff 18.1% 0.7% 0.0% 0.0% 0.1% 0.2% 0.0% 0.0% 0.0%Jan. 12 2013 ILC physics WG general meeting 29

ZhqqWW*qq+vlqq eR(+0.8,-0.3)@ 250 GeV, L=250 fb-1, Mh=120 GeV

　qqWWqqlvqq h->other nlqq nnqq llqq qqqq nnll llll qq

Gen 2,200 33,201 289,791 63,649 282,728 378,726 101,654 611,723 22,270,700Sel 775 1,035 87,873 7,010 16,693 2,384 2,029 30,802 2,238,430

1 741 912 77,425 5,855 4,410 497 1,842 3,848 92,0032 696 852 51,832 1,959 3,245 416 1,361 2,944 18,0103 523 224 3,574 326 481 356 0 0 4,5234 494 207 2,662 271 404 326 0 0 1,4525 491 199 2,546 260 378 311 0 0 1,1966 448 189 2,061 169 348 288 0 0 8527 420 153 742 47 278 259 0 0 7418 378 131 467 14 204 256 0 0 7419 283 74 217 9 128 143 0 0 405

10 171 12 41 0 17 16 0 0 011 145 8 16 0 13 12 0 0 0

Eff 18.7% 0.8% 0.0% 0.0% 0.1% 0.5% 0.0% 0.0% 0.0%

Signal significance=10.4Jan. 12 2013 ILC physics WG general meeting 30

Lepton ID for Wlv with CAL information

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HWW*mu vqq HWW*e vqq HWW*tau vqq HWW*qqqq H others

emu emu

MuID: Etotal/P < 0.6, Eecal/Etotal<0.5eID: 0.6<Etotal/P<1.4, Eecal/Etotal>0.9

One-isolated lepton for Wlv

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E_t

kr

E_Cone

HWWlvqq HWWqqqq HOthers

E_trkE_cone

EPFO>√(Econe+10) && EPFO<90-9/7.5*Econe

Find isolated lepton from charged tracks (Etrk vs Econe(5 degree))

Apply lepton ID with CAL information