Outline : Introduction and Motivation Tevatron and CDF II Analysis Technique Results

Search for Charged Higgs in tSearch for Charged Higgs in ttt Decay Products at CDF IIDecay Products at CDF II

Outline :Outline :× Introduction and Motivation× Tevatron and CDF II × Analysis Technique × Results× The future × Summary

Ricardo EusebiUniversity of Rochester, CDF

2

Previously :Previously :

Next :Next :

Chapter

Introduction and MotivationIntroduction and Motivation

June 21,2005 Ricardo Eusebi - Fermilab Interview 3

Fundamental QuestionsFundamental Questions

Fundamental questions of Contemporary Physics What is dark energy ? Dark matter ? What’s the deal with neutrinos ? Why so many particles ? What’s the reason for their masses ? Are there other symmetries ? Are all the forces related at some high energy ?

Standard Model of particles and fields (SM) Electroweak symmetry (EWS). Massless particles predicted. The Higgs field breaks symmetry (EWSB) generating mass. Predicts h0(SM). But we can’t find the h0. Maybe another mechanism in place ? New particles ?

The unknown mechanism of EWSB is a key aspect to help answer some of the fundamental questions of the Universe.

Intr

o


Electroweak Symmetry BreakingElectroweak Symmetry Breaking

Top Large mass suggest it plays an important role Fermion to which coupling to Higgs is most important, yt=Mt/v ≈ 1.

Standard Model (SM) : 1 Higgs doublet EWSB One Higgs boson, h0(SM)

Decays to bb , , etc. Excluded up to ~114 GeV

Natural Next step : Models with 2 Higgs Doublets (2HDM) EWSB 5 Higgs bosons (h0,H0,A,H±) h0, H0 bb,, gg, W+W-, ZZ, cc A bb,, gg, Zh0, tt H+tb, , cs, W+h0, W+A

h0 excluded up to ~95 GeV

What can be said about H±?

Intr

o


Charged Higgs Production at the TevatronCharged Higgs Production at the Tevatron

Direct C.H. Production Tevatron : qqH+H- Very small production rate Signature hard to distinguish

Indirect C.H. Production Tevatron : top associated

If mtop>mH+mb from tt decays

If mtop<mH with associated top

Maybe Large production rates Clean signature

Intr

o

6


Next :Next :

Chapter

Tevatron and CDF IITevatron and CDF II

Importance of top and higgs in EWSB H± might be produced with top

Where can we study this ?


The CDF II Detector at the TevatronThe CDF II Detector at the Tevatron

Quadrant of the CDF II detector section view

Sampling Calorimeters Iron/scin (HAD) Pb/scin (EM) Coverage ||<3.6

HAD

HAD

HAD

EM

EM

Tracking system Solenoid 1.4 Tesla Central Outer Tracker Drift wires Silicon Detectors determination of secondary vertexes

CDF II

Good determination of angles and energies for e’s, ’s and jets.

Calculation of MET

8


Next :Next :

Chapter

Analysis TechniqueAnalysis Technique

H± might be produced with top Tops are produced at the Tevatron

How can we study it ?



Model : Top and H±

production

Imbalance in channels

Comparison to data

Limits on model

Anal.


Top Pair SM Signatures Top Pair SM Signatures

In the SM, BR(tW+b) >0.99 @95%CL Final state is given by W+ and W- decays

All Hadronic channel (tt bqq′bqq) Large BR Small S/B

Lepton (e,) + Jets channel (tt blbqq′) Second large BR Good S/B overconstrained kinematics

Dilepton channel : (tt blbl) BR is ¼ of L+Jets cleanest channel underconstrained kinematics

Lepton + Hadronic Tau channel(tt blvbh Very small BR S/B~1

Production cross section measured in all these channels

W- jets e

W+

e

jets all-jets

dilepton lepton+jets

lepton

+jets

S/B~0.04

S/B~3S/B~1

S/B~1

Lep

.+T

au

Lep.+Tau

Anal.


Top Pair Search Channels Top Pair Search Channels

Take advantage of existent cross section analyses Lepton+Jets (1, and 2 or more tags) hep-ex/0409029, 0410041 Lepton+Tau To be published Dilepton Phys. Rev. Lett. 93, 142001 (2004)

Lepton+Jets(1) sample requires: Isolated lepton (e,) with ET>20 GeV

MET>20 GeV

at least 4 jets with ET>15 GeV One or more b-tagged jets

Lepton+Tau sample requires: Isolated lepton (e,) with ET>20 GeV

MET>20 GeV

1 jet ET>15 GeV, other with ET>25 GeV

Hadronically decaying tau, PT>15

We will not use them directly as they are. Small changes will be needed.

Dilepton sample requires : Two leptons (ee, μμ, eμ) ET>20 GeV

MET>20 GeV

at least two jets with ET>15 GeV.

Lepton+Jets(2) sample requires: Isolated lepton (e,) with ET>20 GeV

MET>20 GeV

at least 4 jets with ET>15 GeV Two or more b-tagged jets

Anal.


Top-associated Higgs Boson SignaturesTop-associated Higgs Boson Signatures

Higgs Boson decays : h0, H0 bb,, gg, W+W-, ZZ, cc A bb,, gg, Zh0, tt H+tb, , cs, W+h0, W+A

If H± is present, what do we expect ? If H+,

Lepton+Tau sample may show excess w.r.t. SM expectations. Dilepton and Lepton+Jets show a deficit

If H+cs, All channels would show a deficit.

Similar consideration for other H+ decays.

The presence of an H± would affect the relative number of events in each top decay channel, according to its decay.

Look at the relative rates of events in different tt decay channels

Anal.

Search strategySearch strategy



Model : Top and H±

production


Comparison to data

Limits on model

Anal.


Charged Higgs Decays ConsideredCharged Higgs Decays Considered

Assume that top decays either to W+b or H+b tW+b tH+b

Assume that the Higgs decay only as follows : H+cs

H+ H+t*B H+W+h0

We further consider the h0 decays to bb h0bb

Summary : For each top quark we consider 5 possible decays modesB1. tW+b

B2. tH+bcsb B3. tH+bb

B4. tH+bt*Bb B5. tH+bW+h0bW+bbb

The BR to each (Bi) can be predicted from these 5 indep. BR’s

The Narrow Width Approximation (NWA) is implicit.

)(

)(

)(1)(

0

*

hWHBR

btHBR

scHBRHBR

)(1)( bHtBRbWtBR

)( 0 bbhBR

Anal.


Number of Expected Events Number of Expected Events

Dilepton, lepton+jets ≡1 and ≥2 tags, lepton+tau XS analyses (XSA)

,exp

XSAttbackXSAXSA N

Anal.

Includes Luminosity


Number of Expected Events, NNumber of Expected Events, Nbackback


,exp

XSAttbackXSAXSA N

Anal.

Taken from the cross section measurement

Assume non-SM backgrounds to be negligible

ppWh0(MSSM) < (Wh0SM) < 0.2 pb

ppZh0(MSSM) < (Zh0SM) < 0.1 pb

ppH+H-

ppW+H-

H+ production via decay of heavy

SUSY particles. Ignored here.


Number of Expected Events, Number of Expected Events, Dilepton, lepton+jets ≡1 and ≥2 tags, lepton+tau XS analyses (XSA)

,exp

XSAttbackXSAXSA N

Anal.

Use the theoretical production cross section theo=(6.7±0.7)pb, hep-ph0303085

Assume that introduction of the Higgs sector do not change the production mechanism.


Number of Expected Events, BNumber of Expected Events, Bii’s’s


,exp

XSAttbackXSAXSA N

Anal.

Total efficiency calculated from top and anti-top branching ratio decay modes. Recall that the Bi’s are calculated assuming the Narrow Width Approximation is valid. The analysis is limited to regions in which the widths of top and Higgs are each below 15 GeV.

5

1,XSA ,, 0,,,

jihHHiggstopjijiXSAtt mmBB

Bi (Bj) : Branching fractions of top (anti-top) decay mode


Number of Expected Events, Number of Expected Events, i,j XSAi,j XSA


,exp

XSAttbackXSAXSA N

Anal.

5

1,XSA ,, 0,,,


Let’s look at i,j XSA in more detail

Mode-specific efficiency determined given (top, Higgs, mH±, mh0)

It is the efficiency of the tt event with modes i, j given the mass of the charged Higgs and the mass of the neutral Higgs h0.

It takes into account corrections due to large width of the top and Higgs.

Mode-specific efficiency


i,jXSAi,jXSA((toptop,,HiggsHiggs,mH,mH±±,mh,mh00)) is written as (dropping the i,j subindex):

analysisXSA theof categories ofNumber N

1

Nk

kkkXSA LA

LnoSi-noCMX 193±11 pb-1

LnoSi-CMX 175±10 pb-1

LSi-noCMX 161±9.7 pb-1

LSi-CMX 149±9.0 pb-1

resthHHiggstopMCkk mmA 0,,,

Known. Includes eff’s and scale factors from

trigger, lepton, etc. See respective papers.

),,,( 0hHHiggstoprawMCk mm Obtained running the XSA selection code over

the datasets with proper masses. (Dataset contains the 15 different channels.)

Anal. Number of Expected Events, Number of Expected Events, i,ji,j XSAXSA


Problem : Pythia lacks the ME of HProblem : Pythia lacks the ME of H++t*t*bbWbWbbb

Overall small change in efficiencies w.r.t. 3-body decay

Used to have it. Got drop sometime between 2000 and 2004.

Talked to Mrenna about the possibility of adding the decay.

In this analysis we took the ME from PRL 80, 1162 (1998), and place it into a custom made Pythia.

The MSSM parameters do not deform the topology of the decay, just scale it changing the BR.

Thoroughly checked!Thoroughly checked!First check that the eff in the channels w/o a H+->t*b decay does not change.Then check that the density of points in the Dalitz plot agrees with the ME.Finally integrate the Dalitz plot and cross check that it gives the same BR as predicted by PRL 80,1162.

Anal.


i,jXSAi,jXSA((toptop,,HiggsHiggs,mH,mH±±,mh,mh00)) is written as (dropping the i,j subindex):

analysisXSA theof categories ofNumber N

1

Nk

kkkXSA LA

LnoSi-noCMX 193±11 pb-1

LnoSi-CMX 175±10 pb-1

LSi-noCMX 161±9.7 pb-1

LSi-CMX 149±9.0 pb-1

resthHHiggstopMCkk mmA 0,,,

Known. Includes eff’s and scale factors from

trigger, lepton, etc. See respective papers.

topHHiggsHH

H

hHtoprawMCktoptop

t

hHHiggstopMCk mdmdmmWmmmmWmmwH

0 0

),,(),,(),(,,,, 00 ),,( 0hHtoprawMCk mmm Obtained running the XSA selection code over

the datasets with proper masses. (Dataset contains the 15 different channels.)

Anal. Number of Expected Events, Number of Expected Events, i,ji,j XSAXSA


Note : If efficiency is linear, and mass spectrum symmetrical, the correction would be null.

(mtop)

Width Corrections, qualitativelyWidth Corrections, qualitatively A

nal.

Datasetsinterpolation

Top mass = 175 GeV top = 10 GeV

Different widths different mass distributions.

1. Generate Datasets with -- mTop =165,175,185 -- narrow width.

2. Calculate the efficiencies and interpolate between the points.

3. Width-corrected efficiency

integral of (mTop) weighted by the mass distribution


Width correction taken into account when doing :

Width Corrections, quantitativelyWidth Corrections, quantitatively

topHHH

H

hHtoprawMCktop

t

hH

MCk mdmdwHmmWmmmwTmWmmwHwT

0 0

),,(),,(),(,,, 00

ttWbWb

wrt mT=175

mtop (GeV)

165 175 185

Dilep 0.94 1.12

LJets1+ 0.96 1.1

LTauH 0.93 1.09

rawMCk

Width corrections are very small, although we still take them into account.

,...)(wTMCk

After corrections tt-->WbWb

wrt top = 1.4

top(GeV)

5 10 15

LJets1+ 1.002 1.003 1.005

Wt(175,wT) for diff wT

Anal.


Number of Expected Events : Number of Expected Events : SummarySummary


,exp

XSAttbackXSAXSA N

from XS meas.

theo=(6.7±0.7)pb (hep-ph 0303085)

9 quantities needed to fully determine tt,XSA

5 BR’s, top, Higgs, mH± and mh0

Anal.

5

1,XSA ,, 0,,,


from MC

Branching fractions

of each decay mode



Model : Top and H±

production


Comparison to data

Limits on model

Anal.


Methodology : NMethodology : NObsvObsv - -expexp comparison comparison

Comparison by means of Likelihood

where the were defined previously

calculate the likelihood by using MC integration

0 0 0

exp2

2

,,!

...1

|,,,exp

XSAXSAXSAXSAXSAXSAXSA

XSATljllXSA

Tljlljll

bddbbGGn

e

N

nnnnL

XSA

expXSA

!!!!

1|,,,

2

2

1

1

121

2211

lj

nlj

l

nl

lj

nlj

N

n ll

nll

ljlljll n

e

n

e

n

e

n

e

NnnnnL

ljljllljljllll

Relevant parameter set from which the 9 quantities can be calculated

Correlations between XS’s fully taken into account!

Number of candidates in each XS

Product of Poisson's XS’s must be exclusive!

Anal.


Removal of Overlap Between XS’Removal of Overlap Between XS’

Separate the lepton+jets into exactly 1 tag and 2 or more tags

Signal Overlap between lepton+jets and dilepton ? No. Lepton+jets has a dilepton veto

Signal Overlap between XSA and lepton+tau, given by FXSA # events passing both XSA and lepton+tau / # events passing XSA

in (%)in (%) mHmH±=120 GeV

ttttbB + bB + FFDileptonDilepton FFl+jets 1 Tagl+jets 1 Tag FFl+jets ≥2 Tagsl+jets ≥2 Tags

WW (SM) 0.1±0.1 1.1±0.2 1.5±0.4

HW W 0.2±0.2 8.7±0.4 10.1±0.9

HH 1.1±0.7 12±1 15±2

~1% for SM

up to 15%if Higgs is present

Strategy : Implement a lepton+tau veto cut in the lepton+jets and dilepton XS’s. Recalculate signal (and background) efficiencies

Anal.


R. of Overlap, New Background EstimatesR. of Overlap, New Background Estimates

Background Overlap between LTauh and rest, given by FXSA

FXSA # events passing both XSA and Lepton+Tau / # events passing XSA

The Lepton+tau veto cut leaves the backgrounds essentially unchanged !

In events per 193 \invpbBackground Dilep LJets1 LJets2+

FDilepton FL+jets 1 FLJets2+ Z/* --> e+ e- 0.36 ± 0.27 Z/* --> m+ m- (atop27) 0.07 ± 0.3 0/26 Z/ * --> \t+ t- (ztop2t) 0.42 ± 0.13 0/232 ZZ 0.04 ± 0.01 WW (wtop0f|wtop0f atop4x) 0.51 ± 0.19 0/749 0.34 ± 0.06 4/34 1/135 WW (wtop0f|atop4x) 0.51 ± 0.19 0/749 0.34 ± 0.06 1/135 WZ (wtop0q|atop0y) 0.23 ± 0.09 0/369 0.29 ± 0.07 0/265 0.03 ± 0.01 0/14WZ (wtop0q) 0.23 ± 0.09 0/369 0.29 ± 0.07 0/69 0.03 ± 0.01 0/14QCD Fake (atop0\{3,0,f\}) 1.1 ± 0.45 0.37% 6.8 ± 1.7 1/246 Mistag 5.6 ± 0.8 0.22 ± 0.03 W\{bb,cc,c\} 6.1 ± 1.3 0.52 ± 0.15 Single Top 1.1 ± 0.2 0.17 ± 0.04 Total 2.7 ± 0.7 20.3 ± 2.5 0.94 ± 0.1

Anal.



Model : Top and H±

production


Comparison to data

Limits on model

Anal.


We use Bayesian statistics

Parameter we would like to set limits on,

Posterior probability density as a function of

L is the likelihood is the prior in .

Limits in set by integrating the posterior over the maximum density region until obtaining 0.95

Limits on ModelLimits on Model

dnnnnL

nnnnLnnnnP

Tljlljll

TljlljllTljlljll

)(,|,,,

)(,|,,,),,,,|(

2

22

Anal.

32


Next :Next :

Chapter

ResultsResults

Relative rates of events in different channels can set limits on H± models

Can set limits on any model that predicts the 9 quantities.

What models to use?, what are the results ?


Several parameterizations of MSSM

General MSSM : intergenerational mixing. Complex phases. 105 input parameters in addition to the SM ones.

Phenomenological MSSM : Soft SUSY breaking parameters are real. No new sources of CP violation. Matrices for sfermions and trilinear couplings are diagonal. No FCNC at tree level. Masses and trilinear couplings of 1st and 2nd generation are equal. 22 input parameters. Down to 14 if only third generation needed.

GUT-constrained MSSM (mSUGRA) Unification of gaugino masses. Universal scalar masses. Universal trilinear coupling. 4 and a half parameters.

We use the Phenomenological MSSM (pMSSM), with 14 parameters. Use different sets of pMSSM parameters (or benchmark scenarios)

Results : MSSMResults : MSSMRes.


Results : MSSMResults : MSSM , Choice of Benchmarks , Choice of BenchmarksR

es.

LEP benchmarks revisited Maximal and minimal stop

mixing scenarios. Maximize and minimize the

mass of the h0 as a function of tan(b).

All parameters except At fixed. At is chosen so as to maximize or minimize mh0

The decay H+ W+h0 larger around tan(b)≈1 (H,cs,t*b) is bigger at lower

and higher tan(b) values Maximization or minimization of

the h0 mass useful at tan(b)≈1


=-500 GeV =+500 GeV

(extracted from hep-ph/9912516)

Results : MSSM Results : MSSM , Choice of Benchmarks, Choice of BenchmarksR

es.

BR(tH+b) strongly depends on the MSSM parameter

Problem : Previous calculations developed in the large tan(b) approx.

Recalculated to all ranges of tan(b). CDF note 7348 (R. Eusebi, M. Carena) Summary from the last two slides :

has strong effects in the BR(tH+b) predictions at high tan(b) At has strong effects in BR(H+W+h0) at tan(b)≈1.


Results : MSSMResults : MSSM , Choice of Benchmarks , Choice of Benchmarks

(GeV) At(GeV) Rest of parameters (GeV)

B1 -500 2000 M2=M3=MQ=MU=MD=1 TeV

B2 -500 -500 M1=0.4978*M2, ML=ME= 1 TeV

B3 500 500 Ab=At, Atau=500 GeV

B4 500 2800

B5(Minimal) -200 /tan() MQ=MU=MD=1 TeV, M2=M3=200

B6(Maximal) -200 2450GeV + /tan() ME=ML=MQ, At=Ab, Atau=500

B1 and B2 value of =-500 GeV, large BR(tH+b) at large tan(b) Difference is At, that is chosen so as to maximize (B1) and minimize (B2) the mass of the

h0 in the tan(b) ~1 region.

B3 and B4 value of =+500 GeV, small BR(tH+b) at large tan(b) Difference is At, that is chosen so as to maximize (B4) and minimize (B3) the mass of the h0

in the tan(b) ~1 region.

B5 and B6 are the minimal and maximal stop mixing scenarios used at LEP. They minimize and maximize the mass of the h0 at every point in tan(b).

Res.


Results : MSSMResults : MSSM , BR Predictions , BR Predictions

CPsuperH predictions for Benchmark 1

CPsuperH (hep-ph/0307373) predicts the Higgs’ width and BR’s

Res.


MSSM can predict the 9 quantities needed for the efficiency 14 parameters = mH±, tan(b), =other 12 MSSM parameters,

Select a specific benchmarks scenario () For a fixed mH±, scan tan(b) evaluating the posterior.

Integrate the posterior to obtain 95% CL in tan(b)

Results : MSSMResults : MSSM

PHljlljll

Hljlljll

HljlljlldmnnnnL

mnnnnLmnnnnP

)tan())(tan( ,),tan(|,,,

))(tan( ,),tan(|,,,,,,,,|)tan(

21

2121

flat in log10(tan())

Results in the (mH±,tan()) plane

Res.


=500 G

eV

=-5

00 G

eV

Results : MSSM, Benchmarks 1 to 4 Results : MSSM, Benchmarks 1 to 4 R

es.


Results : MSSM, Benchmark 5 and 6Results : MSSM, Benchmark 5 and 6

Maximal stop mixingMinimal stop Mixing

It is clear that these benchmarks are not useful for the charged Higgs search in ttbar decay products.

Res.


Higgs decay to 100 % of time Theoretically favored : t and b Yukawa coupling unification at high energies

For a fixed mH±, scan BR(tH+b) evaluating the posterior. Assume :

BR(H+cs) BR(H+t*b) BR(H+Wh0) 0, Higgs = 1 GeV, top = 1.4/(1-BR(tH+b)) mh0 and BR(h0bb) are irrelevant

Integrate the posterior to obtain 95% CL Repeat for different Higgs masses

Tauonic Higgs Model Tauonic Higgs Model

dnnnnL

nnnnLnnnnP

llljll

llljllljlljll

)( |,,,

)( |,,, ,,,|,

21

2121

Results in the (mH±,BR(tHb)) plane

flat between0 and 1

Res.


Results : Tauonic Higgs ModelResults : Tauonic Higgs Model

BR(tH±b)<0.4 @95%CL for 80 GeV<mH±<160 GeV!

Res.


Scan over all BR combinations and take the worst limit:

Slice the Higgs BR(H+cs, t*b, W+h0) in bins of 0.05. (21 bins each,1771 total) In each bin scan aBR(tH+b) from 0 to 0.9 evaluating the posterior.

In each point in scan : BR(h0bb)0.9, Higgs = 1 GeV, top = 1.4/(1-BR(tHb))

Integrate the posterior and obtain the 95% CL Repeat for all bins and take worst limit. Repeat for different charged Higgs masses

Results : Worst BR CombinationResults : Worst BR Combination

dnnnnL

nnnnLnnnnP

llljll

llljllljlljll

)( |,,,

)( |,,, ,,,|,

21

2121

Results in the (mH,BR(tHb)) plane

flat between 0 and 1

Res.


Results : Worst BR Combination Results : Worst BR Combination

Slice the Higgs’ BR space 1771 bins, spanning all possible combinations. Obtain limit in BR(t->H+b) for each bin.

Depending on the BR combination we can get 95%CL limits from 0.34 to 0.73 in BR(tH+b)

Res.


Results : Worst BR Combination Results : Worst BR Combination

BR(tH+b)<0.83 @95%CL for 80 GeV<mH±<160 GeV!

Res.

46


Next :Next :

Chapter

The Future, The Future, LHCLHC

Results obtained in the context of three different models.

What is expected for the future ?


The Future : The Future : HH++ Production at Production at LHCLHC

Main source : tt,tH+b

Well behind : qqH+H-

bbH+W-

Again, H+ stronger signal comes associated with a top quark.Strongest signal if mH<mTop-mb

Main source : gg,qqtbH-

Well behind : qq(gg)H+H-

bbH+W-

mH+<mTop-mb

mH+>mTop-mb

Fut.


The Future : The Future : LHC tLHC ttt Production Production From Tevatron we know there isn’t much difference between tt

channels. They are to first order balanced.Either : H+ does not exist, or it is not between 80 GeV and 160 GeV the top rarely decays to H+

H+ decays are significantly shared between decay modes.

Expect the same at LHC !

Focus on “realistic analysis” Assume LHC turn on will be slow Uses only a small amount of data Can be done in the early stages of the LHC

Use only 200 pb-1 to compare to the TeV results At LHC this is only 1 week of nominal luminosity data taking !

Fut.


The Future : The Future : LHC tLHC ttt Production Production

(pptt)theo = 833±83 (assume 10% error) WOW! @10 fb-1/year In Atlas specifically (hep-ph/0403021)

Use these numbers to calculate raw estimates for the limits on Charged Higgs.

Channel (Le,) S/B #tt expected

in 200 pb-1

#Background in 200 pb-1

Dilepton 10 1600 160

L+Jets (1+ Tag) 28 5280 185

L+Jets (2+ Tag) 78 WOW-WOW! 1740 22

L+tauhad10 290 29

Fut.

Time needed to understand tracker & b-tags Very large signal to background ratios


The Future : The Future : LHC LHC Limits on Charged Limits on Charged HiggsHiggs

Large exclusion region promptly obtained Note the small uncertainties

Fut.

LHC LHC

Worst BR combination

51


Next :Next :

Chapter

SummarySummary


SummarySummary

We searched for charged Higgs in tt decay products Consideration of many different charged Higgs decay modes. Account for width corrections. Radiative corrections included to the best of our knowledge. Explicitly showed the strong reduction in the theoretical accessible limits, once

all correction are included. Benchmark parameters developed specifically for the charged Higgs search. Best limits to date!!

Used all the resources at hand Touch bases with theoreticians to develop specific formulae. Contacted the authors of CPsuperH to help improve their code. Cross checked every technique with the CDF statistics committee.

Projected the study to LHC Future looks very promising.

53


Next :Next :

Chapter

Backup slidesBackup slides


Present limitsPresent limits

LEP : Direct search; mH± > 78.6 GeV @ 95 % CL, irrespective of tan(b). Combined ALEPH, DELPHI, L3 and OPAL collaborations.

CLEO :Indirect limit; measurement of b->s decay rate results in mH±>(244 + 63/tan(b)1.3) GeV assuming 2HDM only. Can be circumvented in SUSY.

Tevatron :Run I, results in the (mH,tan(b)) plane : CDF : Direct search in t->H+b->b. CDF & D0 : indirect searches using the “Lepton+Jets” (+“Dilepton“ for CDF)

analyses using leading order calculations in similar to this studies. D0 : analysis using NN.


Does H+ decays to those channels only?Does H+ decays to those channels only?

BR(H+bcs++WbB) > 95 % for all tanbeta


The total efficiencies The total efficiencies ij,XSAij,XSA==AAkkxxLLk k (in units of pb(in units of pb-1-1) for the 25 channels are) for the 25 channels are : :

(wTop = 1.4 GeV, wH(wTop = 1.4 GeV, wH±±=1 GeV=1 GeV , mH , mH±±=120 GeV and mh=120 GeV and mh00=80 GeV)=80 GeV)

Total efficiencies summary for Dilep and LJets1Total efficiencies summary for Dilep and LJets1

ij,Dilep (pb-1) i=tWb tHbcsb tHb->b tHbt*Bb tHbWh0b

j=tWb 1.30 ± 0.05

7x10-4 0.78 ± 0.03 1.17 ± 0.04 0.44 ± 0.05

tHbcsb 7x10-4 1.8x10-3 9x10-4 9x10-4 2x10-3

tHb->b 0.78 ± 0.03

9x10-4 0.38 ± 0.03 0.66 ± 0.03 0.34 ± 0.04

tHbt*Bb 1.17 ± 0.04

9x10-4 0.66 ± 0.03 0.95 ± 0.05 0.29 ± 0.04

tHbWh0b 0.44 ± 0.05

2x10-3 0.34 ± 0.04 0.29 ± 0.04 0.03 ± 0.01

ij,LJets1 (pb-1) i=tWb tHbcsb tHb->b tHbt*Bb tHbWh0b

j=tWb 5.28 ± 0.24 3.37 ± 0.15 2.99 ± 0.13 5.13 ± 0.23 3.66 ± 0.20

tHbcsb 3.37 ± 0.15 0.004 ± 0.003 2.07 ± 0.10 2.79 ± 0.13 0.66 ± 0.06

tHb->b 2.99 ± 0.13 2.07 ± 0.10 1.62 ± 0.09 3.25 ± 0.15 3.03 ± 0.18

tHbt*Bb 5.13 ± 0.23 2.79 ± 0.13 3.25 ± 0.15 4.79 ± 0.22 3.19 ± 0.18

tHbWh0b 3.66 ± 0.20 0.66 ± 0.06 3.03 ± 0.18 3.19 ± 0.18 1.08 ± 0.10

Anal.


Total efficiencies summary for LTauH and LJets2+Total efficiencies summary for LTauH and LJets2+

ij,LTauH (pb-1) i=tWb tHbcsb tHb->b tHbt*Bb tHbWh0b

j=tWb 0.17 ± 0.02

9x10-4 1.04 ± 0.05 0.11 ± 0.01 5x10-3

tHbcsb 9x10-4 2x10-3 1x10-3 1x10-3 5x10-3

tHb->b 1.04 ± 0.05

1x10-3 0.83 ± 0.05 0.83 ± 0.05 5x10-3

tHbt*Bb 0.11 ± 0.01

1x10-3 0.83 ± 0.05 0.06 ± 0.01 5x10-3

tHbWh0b 5x10-3 5x10-3 5x10-3 5x10-3 7x10-3

ij,LJets2+ (pb-1) i=tWb tHbcsb tHb->b tHbt*Bb tHbWh0b

j=tWb 1.40 ± 0.07

0.90 ± 0.05 0.79 ± 0.04 2.12 ± 0.10 2.66 ± 0.16

tHbcsb 0.90 ± 0.05

9x10-4 0.58 ± 0.03 1.13 ± 0.06 0.45 ± 0.05

tHb->b 0.79 ± 0.04

0.58 ± 0.03 0.37 ± 0.03 1.43 ± 0.07 1.85 ± 0.12

tHbt*Bb 2.12 ± 0.10

1.13 ± 0.06 1.43 ± 0.07 2.72 ± 0.13 2.71 ± 0.16

tHbWh0b 2.66 ± 0.16

0.45 ± 0.05 1.85 ± 0.12 2.71 ± 0.16 1.38 ± 0.11

The total efficiencies The total efficiencies ij,XSAij,XSA==AAkkxxLLk k (in units of pb(in units of pb-1-1) for the 25 channels are) for the 25 channels are : :

(wTop = 1.4 GeV, wH(wTop = 1.4 GeV, wH±±=1 GeV=1 GeV , mH , mH±±=120 GeV and mh=120 GeV and mh00=80 GeV)=80 GeV)

Anal.


Efficiency Vs. mHEfficiency Vs. mH±± for Dilep and LTauH for Dilep and LTauH

The total acceptance as a function of mHThe total acceptance as a function of mH±± for the tt->HbWb channels for the tt->HbWb channels

lower W masses

softer lep from tau

softer jet from b

harder lep from W

softer jet from b

BR ~5.8 times larger than WbWb

Anal.


Efficiency Vs. mHEfficiency Vs. mH±± for LJets1 and LJets2+ for LJets1 and LJets2+

The total acceptance as a function of mHThe total acceptance as a function of mH±± for the tt->HbWb channels for the tt->HbWb channels

lower W masses

softer lep from tau

harder lep from W

b-tag eff driven

H->Wbb final states larger eff.

b-tag eff driven

close to ttWbWb

4 b final states

Anal.


Type II 2HDM. E.S.B =>5 Higgs bosons (h0, H0, A0, H±) Myriad of new decay channels :

h0, H0 bb, , gg, W+W-, ZZ, cc A bb, , gg, Zh, tt H+tb, , cs, W+h0, W+A

Direct searches are aimed to specific decay channels. Indirect searches can exclude parameter space by combination of channels!

Introduction : Higgs Sector in MSSMIntroduction : Higgs Sector in MSSM : :

Tevatron : H± production from tt via t->H±b, competes with t->WbHow likely is this scenario, given the measured cross sections?

Documentation & Introduction:Documentation & Introduction:

Documentation :Documentation : Official web page :http://b0urpc.fnal.gov/~eusebi/higgs/ CDF Notes :

―7485 Updated Analysis―7557 Removal of the overlap between XS’s―7348 Loop Corrections valid to all tan()―7151 Previous analysis


Note : Why switch from HDECAY to CPsuperH ?Note : Why switch from HDECAY to CPsuperH ?

Because CPsuperH has corrections to the bottom and top Yukawa couplings (hb,ht), which HDECAY lacks.

The hb correction grows with tan()hbhb(1+b) b (...)xtan()

Consequence : Yukawa coupling in CPsuperH grows faster with tan() than in HDECAY.The theoretically accessible region in which |hb|<4 is smaller in CPsuperH.

Compare

HDECAY CPsuperH


Widths grow with phase space and couplings :Widths grow with phase space and couplings :

Higgs width correction, high tanbeta region, accounted for here.Top width correction accounted too.

Note that it decreases with mHiggs. Fairly symmetrical below 15 GeV. Don't expect and don’t see much change in eff.

Top and Higgs WidthsTop and Higgs Widths

Phase space :

High mH ; low top high

Low mH ; high top low

Couplings :

t->Hb coupling get large at high and low tanbeta.

H-> grows with tan()^2.

Outline : Introduction and Motivation Tevatron and CDF II Analysis Technique Results

Documents

Transcript of Outline : Introduction and Motivation Tevatron and CDF II Analysis Technique Results