CMS - Institute for Particle Physics Phenomenology

CMS: Higgs search prospects at 7 TeV, 1 fb -1Andrey Korytov(for CMS Collaboration)Theory Experiment Interplay at the LHCRoyal Holloway University of LondonApril 8-9, 2010Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 1

OutlineStage for Higgs searches at LHC: currentlimits from LEP and TevatronCMS Projections for 7 TeV and 1 fb -1How did we start? – a look at the first dataAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 2

Projected integrated luminosity100 pb -1 by Nov 2010Nov 2010: heavy ionsDec–Jan: technical stop1 fb -1 by end of 20112012: commissioning for higherenergy and higher luminosity(may take more than a year)Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 3

OutlineStage for Higgs searches at LHC: currentlimits from LEP and TevatronCMS Projections for 7 TeV and 1 fb -1How did we start? – a look at the first dataAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 4

LHC at 7 TeV: general considerationsLEP limits: not expected to changeTevatron in 2011: 2 TeV, 10 fb -1LHC run 2010-2011: 7 TeV, 1 fb -1Channels of prime interest are those that will allow us to further the Higgs sensitivityhigher cross sections at LHC• e.g., gg luminosity with sqrt(s)>70 GeVat LHC is >10 times larger than at Tevatronbetter detector performance• e.g., γγ mass resolution of CMS isabout 3 times better than that ofCDF and D0 (3 GeV)and combination of the aboveAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 5

Higgs search landscape as of today:SM Higgs95% CL exclusion limitsApril 2003LEP:m H > 114.4 GeVhttp://lephiggs.web.cern.ch/LEPHIGGS/Tevatron:m H ≠ 163-166 GeVhttp://tevnphwg.fnal.gov/EWK + LEP + Tevatronm H d 160 GeVhttp://project-gfitter.web.cern.ch/project-gfitter/LHC : TevatronggH CS Ratio (m H ~160) ~20VH CS Ratio (m H ~120) ~4Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 6

Higgs search landscape as of today:MSSM Neutral Higgses95% CL exclusion limitLEP Tevatrontanβ~30http://lephiggs.web.cern.ch/LEPHIGGS/http://tevnphwg.fnal.gov/mhmax scenario:• least restrictive on the (m A , tanβ) plane given the LEP search limits•M SUSY =1 TeV, X t =2 TeV, M 2 =200 GeV, M 3 =800 GeV, μ=+200 GeVLHC : TevatronggbbbbΦ CS Ratio (m Φ ~100) ~20Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 7

Higgs search landscape as of today:MSSM Charged HiggsTevatron95% CL exclusion limitsLEPhttp://lephiggs.web.cern.ch/LEPHIGGS/LHC : TevatronppttCS Ratio ~20Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 8

Higgs search landscape as of today:Beyond SM/MSSM (1 st example)Fermiophobic HiggsIf the EWK symmetry breaking Higgs has nothing to do with fermion masses:• SM Higgs limits at Tevatron evaporate• High mass: ggh, hWW (decay mode is OK, but the production disappears)• Low mass: VH, hbb (production is OK, but the decay mode disappears)• Only one fermiophobic-specific Higgs search hγγ remains (also H and qqH, HWW)(How about fermion masses? E.g., all this can be self-consistently accommodated in models with two doublets of Higgs fields)m H > 110 GeVm H > 106 GeVm H > 103 GeVLHC : Tevatron VBF+VH CS Ratio ~7γγ mass res. ratio ~3Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 9

Higgs search landscape as of today:Beyond SM/MSSM (2 nd example)Double-charged Higgsarises in models with extra higgs tripletsstrongly motivated, it allows for small neutrino masses(an alternative to see-saw type mechanisms)m H > 104-150 GeV, depending on channel and assuming 100% BRBR(H ±± →μμ)=100%BR(H ±± →eμ)=100%BR(H ±± →ee)=100%BR(H ±± →μτ)=100%2004BR(H ±± →eτ)=100%2008BR(H ±± →μμ)=100%2008CDF240 pb -1 CDF350 pb -1LHC : TevatronqqH ++ H -- CS Ratio ~3Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 10

OutlineStage for Higgs searches at LHC: currentlimits from LEP and TevatronCMS Projections for 7 TeV and 1 fb -1How did we start? – a look at the first dataAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 11

Projection workflowProjections to be shown are NOT new analyses done with 7 TeV MC samples andnew detector simulation/reconstruction softwareWe tried to strike the right balance: not too aggressive -- not too conservativeStart out from public results at 14 TeV (int. luminosity from 1-30 fb -1 )Re-scale signal and bkgd event counts by the ratio of 7 TeV : 14 TeV cross sectionsand project for the integrated luminosity of 1 fb -1No corrections for higher acceptance at smaller sqrt(s), up to ~20%No corrections for improvements in reconstruction (efficiencies, resolution)Modify systematic errors:• for backgrounds derived from control samples, scale as 1/sqrt(N)• other errors: assess whether to keep as is (e.g. theoretical errors) or inflate to correspondto a smaller data set• take into account error correlationsStatistical analysis:• Use re-scaled event counts and re-evaluated systematic errors• Exclusions: Modified Frequentist (CL s)• Significance: Profile LikelihoodAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 12

SM Higgs: forerunner channelsCMS Physics Technical Design Report 2006NLO cross sectionsSystematic errors includedUpdates since 2006for 14 TeV and 1 fb -1https://twiki.cern.ch/twiki/bin/view/CMS/PublicPhysicsResults• HWW PAS HIG-08/006sensitivity improved wrt 2006• HZZ PAS HIG-08/003approx no changes in sensitivity• VBF Hττ PAS HIG-08/008fast loss of sensitivity [ faster than 1/sqrt(L) ]due to running out of signal eventsBottom line: depending on m H ,forerunners remain the same,i.e. inclusive WW, ZZ, γγPAS – Physics Analysis SummaryAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 13

SM Higgs cross sections at 7 TeVInclusive Cross Section Ratio1(New 7 TeV) – to – (PTDR 14 TeV)0.90.80.70.60.50.40.30.20.1Total cross section ratio2gg( NNLO) + VBF( NLO) + VH ( NLO) + ttH ( LO)ratio =LHC gg( 10 NLOTeV) + VBF( NLO) + VH ( NLO) + ttH ( LO)1.510.5free lunch: ~30% gain(projections to be showndo include these gains)0100 200 300 400 500 600mH00 100 200 300 400 500 600 700m H (GeV)Sub-processPTDRnowtools used nowgg fusionNLONNLOHggTotalVBFNLONLOVV2HVHNLONLOV2HVttHLOLOHQQAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 14

Rescaling backgroundsGeneral case backgroundsExample of a special case backgroundDiphox, Gamma2MC:born+1frag +2frag + box [all at NLO]Calculated with the Hγγ photon cutsBORN BOXONE FRAG TWO FRAGaverage 0.446Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 15

SM H→WW→2l2vReference: HIG-08/006Method:treat three final states μμ, ee, eμ separatelytwo isolated leptonsMETjet veto (0-jets bin)optimize in three mass ranges 120-140, 150-170, 180-20014 TeV, 1 fb -1count herelook for an excess above a cut on the MVA output[counting experiment]main backgrounds are assessedusing data-driven techniques: WW, tt, W+jets, Drell-Yan50Events at 7 TeV, 1 fb -1signalbkgd40Number of Events3020100100 120 140 160 180 200 220Higgs Mass (GeV)Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 16

SM H→WW→2l2vReference: HIG-2008/006Method: Counting above a MVA-output cutThree sub-channels: ee, μμ, eμSM Higgs expected excluded range150-185 GeVSM Higgs discovery level sensitivity160-170 GeVAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 17

SM H→WW→2l2vReference: HIG-2008/006Method: Counting above a MVA-output cutThree sub-channels: 2e, 2μ, eμTEVATRONCDF HWWCDF Note 1002, March 16, 2010D0 HWWSM Higgs expected excluded range: 150-185 GeVPhys. Rev. Lett. 104, 061804 (2010) , Feb 12, 2010Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 18

SM H→ZZ→4lReferences:HIG-08/003, NOTEs 2006/115, 2006/122, 2006/13614 TeV, 1 fb -1Method:four isolated leptonslepton impact parameter vetolook for a 4l-resonance mass peak[counting in a sliding mass window]dominant background ZZ [assessed from data—Z events]4Events at 7 TeV, 1 fb -1signalbkgdNumber of Events3210100 1000Higgs Mass (GeV)Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 19

SM H→ZZ→4lReferences: HIG-2008/003 andNOTEs 2006/115, 2006/122, 2006/136Method: Counting in a 4l-mass windowThree sub-channels: 4e, 4μ, 2e2μTEVATRONNo HZZ public results,but...4G (four-generation)Higgs limits from CDF+D0HWW channelSensitivity at m~200 is similar to HWW (effect of low lumi)D0 Note 6039-CONF, March 11, 2010SM Higgs with 4 fermion generations-ggH cross section goes up by a factor 3 2 =9 (regardless of how heavy the 4 th generation quarks are)- expected exclusion limit – up to 500 GeVAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 20

SM H→γγReference: NOTE-2006/11214 TeV, 30 fb -1Signal x 10Method:two isolated photons [no categories]look for γγ-resonance mass peak[counting in a sliding mass window]bkgd is assessed from sidebandsEvents at 7 TeV, 1 fb -1250signalbkgd200Number of Events150100500100 110 120 130 140 150 160Higgs Mass (GeV)Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 21

SM H→γγReference: NOTE-2006/112Method: Counting in a mass windowNo photon categoriesTEVATROND0D0 Note 6580-CONF, 11 March 2009CDFNote:This projection does not rely on Higgs specific kinematics.So, one can view it as a generic ppXγγ searchCDF Note 9586, Oct 30, 2008Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 22

SM VBF H→ττ (1)Reference:NOTE-2006/088, PAS HIG-08/008Method:VBF signatureand counting events in a ττ-mass windowττφηrapidity gapττConsider example of m H =135PTDR:14 TeV and 30 fb -1 , signal=7.9, signal:bkgd ~ 4:114 TeVPAS HIG-08/008 (re-optimized)14 TeV and 1 fb -1 , signal=1.1, signal:bkgd ~ 1:10exclusion limit r~12Next year?7 TeV and 1 fb -1 , signal drops by 50%,r will get worse (it will be far behind r~4 for Hγγ)This channel is certainly not a forerunner with early data…Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 23

SM VBF H→ττ (2)And there is one more problem with this channel…Recently, it was realized thatthe classical VBF signature•two highest E T jets in forward-backward directions• and large rapidity gap |η jet1 -η jet2 | with no jets in between (jet veto)may have large phenomenological uncertainties for signal efficiencyττφηrapidity gapττkill theseeventsChristoph Hacksteiny* = y i–½(y 1+y 2)For details:C. Hackstein at HGF-Alliance-2009: HGF-Alliance "Physics at the Terascale" annual meeting 2009, 11-13 Nov 2009, DESY, HamburgC.AndreyHacksteinKorytovat DPG-2010:(UniversityJahrestagungof Florida)2010Theoryder DPG,ExperimentDeutsche PhysikalischeInterplay at theGesellschaft,LHC , April15-199, 2010Mar 2010, Bonn University, Bonn24

SM Higgs Combination γγ+WW+ZZTEVATRONCDF500CDF Note 9999, Nov 17, 2009(the recent WW update not yet included)D0SM Higgs expected excluded range: 145-190 GeVSM Higgs with 4 fermion generations:

Fermiophobic HiggsSM Hγγ exclusion r~4Fermiophobic/SM ratios10010BR hf /BR SMσ hf /σ SM (7 TeV)(σ hf ×BR hf )/(σ hf ×BR SM )Ratios10.10.01100 110 120 130 140 150mH (GeV)Fermiophobic/SM (see plot on the right)lose a factor of 10 in cross section [blue line]Gain a large factor in BR(Hgg) [black line]CS x BR is larger than that of SM up to 130 GeVIf we do nothing special for fermiophobic Higgs,r~4 for SM Higgs (see left plot) implies thatwe can exclude fermiophobic Higgs with m~110 GeV (see right plot), which isbetter than Tevatron, comparable to the Combined LEP limitAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 26

MSSM Higgs bbΦ at 7 TeVCross Section Ratios10.90.8FeynHiggshbbHbbAbb7TeV : 14TeV CS Ratio0.70.60.50.40.30.20.100 100 200 300 400 500 600Higgs massAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 27

MSSM bbΦ, Φ→ττReferences:NOTE 2006/075NOTE 2006/101NOTE 2006/105Method:Background pdf(m ττ)14 TeVZ+bb/cc/jetsttred lines are fitsisolated τ hadτ μτ hadτ eτ eτ μMETone b-tagged jetveto extra jetsEvents at 7 TeV, 1 fb -110signalbkgdbuild ττ-mass using collinear approximationcounting events in a sliding ττ−mass window[counting experiment]dominant backgrounds [assessed from data]• Z+bb/cc/jets• ttNumber of Events50100 200 300 400 500Higgs Mass (GeV)tanβ=20mhmaxμ=+200Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 28

MSSM bbΦ, Φ→ττReferences: NOTEs 2006/075, 2006/101, 2006/105Method: Counting in a ττ-mass windowTEVATROND0+CDF (m A200)discoverexcludeCDF note 9071, October 22, 2007Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 29

OutlineStage for Higgs searches at LHC: currentlimits from LEP and TevatronCMS Projections for 7 TeV and 1 fb -1How did we start? – a look at the first dataAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 30

First steps with data: photonsDi-photon resonancesCMS PAS PFT-10-001Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 32

First steps with data: electronsElectrons from conversionsCMS PAS EGM-10-001γ(e + e - ) conv π 0 peakAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 33

First steps with data: “taus”CMS PAS PFT-10-001Fake-tau rate vs jet p TAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 34

First steps with data: jetsDi-jet eventCMS PAS JME-10-00139 GeV31 GeVAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 35

First steps with data: METThree different algorithms for METCaloMET: using calorimeter information onlytcMET: HCal information is track-correctedpfMET: particle-flow informationCMS PAS JME-10-002Important: in Higgs analyses, typical MET is very moderate, tens of GeVAgreement between MC and data in this range is quite remarkableAndrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 36

ConclusionsWith 7 TeV and 1 fb -1 of data,CMS (and surely ATLAS) will be on the map for Higgs searchesCMS projections:SM discovery sensitivity: 160-170 GeVSM exclusion sensitivity: 145-190 GeVMSSM neutral Higgs discovery rich: down to tanβ~20 at low m AMSSM neutral Higgs exclusion rich: down to tanβ~15 at low m AMSSM light charged Higgs: production rate is higher than at TevatronBeyond SM/MSSM: a number of opportunities are out there…First look at data and running experience are very positive!Andrey Korytov (University of Florida) Theory Experiment Interplay at the LHC , April 9, 2010 37