Search for doubly charged Higgs bosons in e-μ channel

at √s=7TeV at CMSJongseok Lee, Youngil Choi, Sungeun Lee, Suyong Choi1,

Sungkyunkwan Univ., 1Korea Univ.April 23, 2012

1

Contents

• Introduction

• Samples

• HLT and Skim

• Lepton and event selection

• Signal & background efficiency

• Limit

2

Introduction

• In models with expanded Higgs sector, one can have Higgs triplets.

Doubly charged Higgs

• Pair production : through Drell-Yan process

• Decays : • In this analysis, we only consider e-μ decays (Br(H++ l+l+)=1 is assumed, l+l+ = e+e+ or e+μ+ or μ+μ+)

3

W W,H ll

in CMS_NOTE2006_081

cross section(hep-ph/9610237)

Samples• Used CMSSW version : 4_4_2

• MC signal samples (√s=7TeV) : 0.5M events of full simulation data → H++H-- to l+l+l-l-

→ M(H±±) = 130, 150, 170, 200, 300, 400, 500GeV • MC background samples : 50k events of full simulation data → ZZJetsTo4L, WZJetsTo3LNu TTJets, ZJetsToLL, QCD

• Data samples : Lint = 4.63 fb-1

4

calculated by Michael Spira

HLT and skim efficiencies

5

• Used paths :HLT_DoubleMu7HLT_Ele17_CaloIdL_CaloIsoVL_Ele8_CaloIdL_CaloIsoVLHLT_Mu8_Ele17_CaloIdLHLT_Mu17_Ele8_CaloIdL

• Skim conditions :firstpt>15 GeV && secondpt>10 GeV

Lepton & event selection

6

• Electron selection pT>10 GeV, |η|<2.5, |d0|<0.02, sip<4, nchi2<10, charge consistent, eidMedium

• Muon selectionpT>10 GeV, |η|<2.4, global muon, |d0|<0.02, sip<4, nchi2<10, hits_val>20, nstation>=1

• Preselection : nlep+>=2, nlep->=2, Mll>10 GeV

• Event selection - mass dependent cut

relative isolation : (IsoPttrack + IsoPtecal + IsoPthcal)/pt < cut value

di-lepton pt cut : Max(pT(H++),pT(H--),pT(Z1),pT(Z2)) > cut value

# of primary vertices

7

Before pileup reweighting

after pileup reweighting

nlep+>=2, nlep->=2, Mll>10

exp

ect

ed

# o

f even

t

exp

ect

ed

# o

f even

t# of primary vertices

# of primary vertices

8

Electron cut variables(√s=7TeV, Lumi = 4.63 fb-1)

GeV

mm

exp

ect

ed

# o

f ele

ctro

ns

exp

ect

ed

# o

f ele

ctro

ns

exp

ect

ed

# o

f ele

ctro

ns

exp

ect

ed

# o

f ele

ctro

ns

nlep+>=2, nlep->=2, Mll>10

exp

ect

ed

# o

f ele

ctro

ns

exp

ect

ed

# o

f ele

ctro

ns

9

Muon cut variables(√s=7TeV, Lumi = 4.63 fb-1)

mm

nlep+>=2, nlep->=2, Mll>10

GeV

exp

ect

ed

# o

f m

uon

sexp

ect

ed

# o

f m

uon

s

exp

ect

ed

# o

f m

uon

sexp

ect

ed

# o

f m

uon

s

exp

ect

ed

# o

f m

uon

sexp

ect

ed

# o

f m

uon

s

10

Iso for event selection(mH++=200GeV, √s=7TeV, Lumi = 4.63 fb-1)

exp

ect

ed

# o

f even

t

nlep+>=2, nlep->=2, Mll>10

exp

ect

ed

# o

f even

t

exp

ect

ed

# o

f even

texp

ect

ed

# o

f even

t

exp

ect

ed

# o

f even

texp

ect

ed

# o

f even

t

H++H-- e+e+e-e-

H++H-- e+μ+e-μ-

H++H-- e+e+e-μ-

H++H-- e+μ+μ-μ-

H++H-- e+e+μ-μ-

H++H-- μ+μ+μ-μ-

11

di-lepton PT for event selection(mH++=200GeV, √s=7TeV, Lumi = 4.63 fb-1)

GeV

exp

ect

ed

# o

f even

t

nlep+>=2, nlep->=2, Mll>10, isolation

exp

ect

ed

# o

f even

t

exp

ect

ed

# o

f even

texp

ect

ed

# o

f even

t

exp

ect

ed

# o

f even

texp

ect

ed

# o

f even

t

H++H-- e+e+e-e-

H++H-- e+μ+e-μ-

H++H-- e+e+e-μ-

H++H-- e+μ+μ-μ-

H++H-- e+e+μ-μ-

H++H-- μ+μ+μ-μ-

GeV

GeV

GeV

GeV

GeV

12

Signal & bkg. efficiency

Cuts H++H-- to 4μ(200GeV)

ZZ to 4l TTJets ZJetsToLL

nlep+>=2, nlep->=2, Mll>10 67.2%±1.4%

4.168%±0.007%

8.10e-05%±0.01e-05%

0

ISOrel < cut_value 67.0%±1.4%

4.133%±0.007%

- -

di-lepton pt > cut_value 48.5%±1.0%

0.2292%±0.0004

- -

Signal & background efficiency

genNefficiencybkgsignal

)1( ,

events generated of #

cuts applied candidates H of # .)(

Mass of H++(m(H++)=200GeV, √s=7TeV, Lumi = 4.63 fb-1)

13GeV

exp

ect

ed

# o

f even

t

nlep+>=2, nlep->=2, Mll>10, isolation

exp

ect

ed

# o

f even

t

exp

ect

ed

# o

f even

texp

ect

ed

# o

f even

t

exp

ect

ed

# o

f even

texp

ect

ed

# o

f even

t

GeV

GeV

GeV

GeV

GeV

H++H-- e+e+e-e-

H++H-- e+μ+e-μ-

H++H-- e+e+e-μ-

H++H-- e+μ+μ-μ-

H++H-- e+e+μ-μ-

H++H-- μ+μ+μ-μ-

Mass of H++(m(H++)=200GeV, √s=7TeV, Lumi = 4.63 fb-1)

14GeV

exp

ect

ed

# o

f even

t

nlep+>=2, nlep->=2, Mll>10, isolation, di-lepton pt

exp

ect

ed

# o

f even

t

exp

ect

ed

# o

f even

texp

ect

ed

# o

f even

t

exp

ect

ed

# o

f even

texp

ect

ed

# o

f even

t

H++H-- e+e+e-e-

H++H-- e+μ+e-μ-

H++H-- e+e+e-μ-

H++H-- e+μ+μ-μ-

H++H-- e+e+μ-μ-

H++H-- μ+μ+μ-μ-

GeV

GeV

GeV

GeV

GeV

Exclusion limit

15

nlep+>=2, nlep->=2, isolation, di-lepton pt cut

mmmmExpected Limit : 359Observed Limit : 361

eeeeExpected Limit : 327Observed Limit : 329

eeemExpected Limit : 344Observed Limit : 344

eemmExpected Limit : 420Observed Limit : 420

ememExpected Limit : 334Observed Limit : 336

emmmExpected Limit : 371Observed Limit : 342

Result

16

Expected # of events at √s=7TeV & Lint=4.63fb-1

H++H-- to 4e H++H-- to 2e2μ H++H-- to 4μ

M(H++) signal bkg / data signal bkg / data signal bkg / data

130 GeV 230 1.68 / 0 636 0.00384 / 0 330 2.96 / 1

150 GeV 115 0.845 / 0 390 0.00384 / 0 189 1.50 / 0

170 GeV 78.7 0.845 / 0 229 0.00321 / 0 111 0.864 / 0

200 GeV 35.2 0.316 / 0 124 0.00321 / 0 62.7 0.864 / 0

300 GeV 4.63 0.0534 / 0 16.8 0.00032 / 0 8.12 0.114 / 0

400 GeV 1.09 0.0268 / 0 3.94 0.00032 / 0 1.68 0.0291 / 0

500 GeV 0.283 0.00726 / 0 1.12 0.00032 / 0 0.413 0.00442 / 0

intL efficiency sig.(bkg.) section cross final events of # Expected

nlep>=4, isolation, di-lepton pt cut

backup

17

• Isolation

Isolation• isolation in tracker only :

• isolation in tracker+calorimeter :

• relative isolation in tracker only :

• relative isolation in tracker+calorimeter :

18

tracker

iTPISO

rcalorimete

iT

tracker

iT E PISO

T,tracker

iT P / PISO

T,rcalorimete

iT

tracker

iT P / E PISO