cms upgrade physics corfu2017 vrekovic... · 2017-09-18 · physics project prioritization •what...

LHCUpgradePhysicsinCMS(HiggsSector)

VladimirRekovicfortheCMSCollaboration

9/8/17 V.Rekovic,LHCUpradePhysicsinCMS 1

LHC/HL-LHCPlan


PU140(200)@25(50)nsbunchcrossing

Detectorandtriggerchallenges

• Need detectors and trigger with high performances from low to high energy scales – 125 GeV SM-like boson measurements– Multi-TeV new physics searches

• Phase 1 Upgrade: twice LHC design luminosity– Event pileup reaches ~50 collisions per beam crossing (@ 25 ns)– Factor 5 increase in trigger rates relative to 2012 run

• Phase 2 Upgrade: 5x LHC design luminosity– Event pileup reaches ~140 collisions per beam crossing (@ 25 ns)– Need solutions to cope with very high rates (10-15 x 2012), radiation and pileup

• CMS Documentation:- Phase I & II Upgrade Technical Proposal (CERN-LHCC-2011-006,2015-010)- PhaseIIUpgradeScopeDocument” (CERN-LHCC-2015-019 )

ATLAS and CMS were designed to cope with L= 1-2 x1034 cm-2s-1


Physicsprogrampriorities

• With LHC 13/14 TeV data until ~2022 (~300 fb-1)– Measure SM-like scalar boson properties

• mass, JPC

• individual couplings with 5-15% precision– Search for new physics at a higher scale (new energy region)

• SUSY• Exotics

• With HL-LHC 14 TeV data until ~2032 (~3000 fb-1)– High Precision SM scalar boson measurements– Study Higgs boson rare decays and self-coupling– Study VV scattering– Characterize any New Physics discovered during Phase 1 at 14 TeV– Search for new physics in very rare processes

The discovery of a SM-like scalar boson at mH~125 GeV defines the physics priorities


HiggsPhysicsatHL-LHC• The High-Luminosity LHC has been identified as the highest priority program in

High Energy Physics by both the European Strategy Group and the US Particle Physics Project Prioritization

• What can we do at HL-LHC in the Higgs sector?– Measure existing decay channels with the highest precision– Observe rare Higgs decays

• H→μμ• H→Zγ• H→cc (?)

– Double Higgs production (Higgs self-coupling)– Vector boson scattering– Look for small deviations from SM predictions


CMSupgradeprogramLS1 Projects• Complete Muon coverage (ME,RE4)• Improve muon operation, DT

electronics• Replace HCAL photo-detectors in

Forward (new PMTs) and Outer (HPD→SiPMs)

• DAQ1→DAQ2• L1 Trigger upgade

LS1

Phase 1 Upgrades• New Pixel detector, HCAL electronics

and L1-Trigger upgrade• GEMs for forward muon detector

LS2 (2018)

Phase 2 Upgrades:Tracker replacement, L1 Track-Trigger

• Forward: calorimetry, muons and tracking• High precision timing for PU mitigation• Further Trigger upgrade (higher granularity)• Further DAQ upgrade

LS3 (~2023)

ME4/2

RE4

Pixel

HO


CMSPhaseII– HGCal – Silicon-basedCalorimetry

• InHL-LHCPile-upwillbecomeevermoresevere,makingtheidentificationofelectromagneticobjectsmorechallengingandswampingtherelatively-isolatedVBFandVBSjetswithincreasingQCDmultijetbackground.

• NewCalorimetryintheforwardregionhigh-granularitysamplingcalorimeter.- silicon/tungstenelectromagneticsection- twohadronicsections,bothusingbrassastheprimaryabsorbermaterial.

• Provideprecisionandradiationhardness


CalorimeterPile-UpMitigation

• Consider10ps~20psTOFcalorimeterresolutionforMIP’sandγ,togetherwithTrackercoverage:

• TrackingidentifieslocationZ0ofinterestingcollisionvertex

• TOFofchargedparticlesfromthatcollisionidentifiestimet0ofinterestingcollision

• UseZlocationandtimetoselectcalorimeterclustersassociatedtoZ0&t0ofinterestingcollision

• ForH->γγ usetimingofγ’s toproducereducedlistofpossiblycompatiblevertices,thenselectbestmatchwithsimilarcriteriaasforpresentanalysis

• OngoingdiscussionforTOFdetectorsinfrontofBarrelandEndCap Calorimeter

•CollisionsaredistributedoverseveralcminZ,andafew100ps intime.


CMSPhaseIITrackingTrigger

• DesignmoduleswithpT discrimination• Correlatehitsintwoclosely-spacedsensorstoprovidevector(stub)intransverseplane:angleisameasureofpt

• ExploitthestrongmagneticfieldofCMS

• Level-1“stubs”areprocessedintheback-end• FormLevel-1tracks,pT above2~2.5GeV• Usetoimprovedifferenttriggerchannels(ratereductionx5-10forleptontriggers)


CMSPhaseIITrigger• ReplaceEcal BarrelandEndcapFrontEndelectronics

• Latency12μsec• Provideindividualcrystallevel(not5x5sums)triggerinformation

• L1Acceptrate~750kHz• Moreacceptancelowerthreshold

• Trackingtrigger• Leptons:Ptcut&isolation.Jets:vertex

• NewL1Trigger(Calorimeter,Muon,Global)takeadvantageofTrackTriggerandcorrelationsb/wobjects

• HLToutputrateincreasex10,to10kHz


CMSPhaseIIMuondetectorIncrease det. acceptance up to |η|=4.0

>40% more H→4μ events


CMSHiggsbosonprojections

• CMSreportedtheexpectedsensitivityofvariousHiggsbosonanalysesattheHL-LHCin,basedonprojectionsof8TeVmeasurementsusing2012CMSdata,andDELPHESsimulationstudiesincorporatingthePhase-IIdetectorupgrades.(CMSPhaseIITechnicalProposal)

• Thestudiespresentedhererepeatandcomplementthepreviouspublicresultsat300fb−1and3000fb−1,updatingthecorrespondinganalysestechniquestotheircurrentstatus.


HiggsbosonprojectionsafterLS1Approaches adopted for physics projections• CMS: projections are presented under four different scenarios assumed

for the size of systematic uncertainties:

- S1: all systematic uncertainties are kept unchanged with respect tothose in current data analyses

- S1+ : S1 + effects of higher pileup conditions and detector upgrades on the future performance of CMS are taken into account

- S2: the theoretical uncertainties are scaled by a factor of 1/2, while other systematical uncertainties are scaled by 1/√L (till lower limit from estimates of achievable accuracy with upgrade detectors)

- S2+: S2 + effects of higher pileup conditions and detector upgrades onthe future performance of CMS are taken into account


Higgscouplingratiosvs.massMass-scaled coupling ratios vs. particle mass

Particle mass (GeV)0.1 1 10 100

1/2

/2v)

V o

r (g

fλ

-410

-310

-210

-110

1WZ

t

bτ

µ) fitε (M,

68% CL95% CL

68% CL95% CLSM Higgs

68% CL95% CLSM Higgs

CMS (7 TeV)-1 (8 TeV) + 5.1 fb-119.7 fb

mass (GeV)0.1 1 10 100

1/2

or (

g/2v

)λ

-410

-310

-210

-110

1WZ

t

bτ

µ

68% CL

CMSProjection

(14 TeV)-13000 fb


H→γγ

Expected uncertainty0.1− 0 0.1 0.2 0.3 0.4 0.5

ttHγγµ

VBFγγµ

ggHγγµ

γγµ

ECFA16 S1+ ECFA16 S2+

ProjectionCMS

γγ→H

TeV)(13-1fb3000

0.03 (theo.)±0.02 (exp.) ±0.01 (stat.) ±0.06 (theo.)±0.08 (exp.) ±0.01 (stat.) ±

Expected uncertainty0.1− 0 0.1 0.2 0.3 0.4 0.5

ttHγγµ

VBFγγµ

ggHγγµ

γγµ

ECFA16 S1 ECFA16 S2

ProjectionCMS

γγ→H

TeV)(13-1fb300

0.03 (theo.)±0.02 (exp.) ±0.04 (stat.) ±0.06 (theo.)±0.08 (exp.) ±0.04 (stat.) ±

CMS-PAS-HIG-16-020

ReconstructM(γγ)MustknowE(γ) andvertex.

µ2− 0 2 4 6 8-1.4+2.0TTH Leptonic Tag 1.15

-1.2+1.6TTH Hadronic Tag 2.10

-0.8+1.2VBF Tag 1 0.04

-0.6+0.8VBF Tag 0 1.58

-0.6+0.9Untagged 3 1.33

-0.31+0.32Untagged 2 0.44

-0.29+0.33Untagged 1 1.04

-0.5+0.6Untagged 0 0.95

0.18−0.21+ = 0.95

combinedµ

ProfiledHm

σ 1±Combined

σ 1±Per category

SMµ=µ

Preliminary CMS

γγ→H

TeV) (13-1 12.9 fbS/

(S+B

) Wei

ghte

d Ev

ents

/ G

eV

0

1000

2000

3000

4000

5000

DataS+B fitB component

σ1 ±σ2 ±

S/(S+B) weightedAll categories=126.0 GeVHm

--

Preliminary CMS TeV) (13-1 12.9 fbγγ→H

(GeV)γγm100 110 120 130 140 150 160 170 180

100−

50−

050

100150 B component subtracted

Projectto3000fb-1

CMS-PAS-HIG-16-033


Leadingexperimentaluncert- Luminosity(reduced~1.5%)- JES

H→γγandTiming

(%) fid.σRelative expected uncertainty on 1− 0 1 2 3

S2+ (Pes.)

S2+ (Med. )

S2+ (Opt. )

S2 0.029 (exp.)± 0.014 (stat.) ±

0.031 (exp.)± 0.015 (stat.) ±

0.031 (exp.)± 0.016 (stat.) ±

0.030 (exp.)± 0.017 (stat.) ±

Uncertainty relative to S21 1.05 1.1 1.15 1.2

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1Projection CMSγγ→H

) < 10 GeV1, 2γ (R=0.3

genIso

)| < 2.51, 2γ (genη|

γγ ) m4

1 ( 31) >

1 (2)γ (

Tgenp

fiducial volume :

TeV) (13-1fb 3000

exp.⊕stat.

stat. only

(GeV)γγm110 115 120 125 130 135

dummy0

arbi

trary

uni

ts

signal modelsS/(S+B)-weighted

dummy0

relative to S2 (GeV)effσ1 1.1 1.2 1.3 1.4

=1.71 GeVeffS2σ

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

S2 (80% Vertex Efficiency)

S2+ Optimistic (75% Vertex Efficiency)

S2+ Intermediate (55% Vertex Efficiency)

S2+ Pessimistic (40% Vertex Efficiency)

Projection CMSγγ→H

) < 10 GeV1, 2γ (R=0.3

genIso

)| < 2.51, 2γ (genη|

γγ ) m4

1 ( 31) >

1 (2)γ (

Tgenp

fiducial volume :

TeV) (13-1fb 3000

VertexidentificationscenariosS2– 80%vtx id,nodegradationduetoPUS2pessimistic– 40%vtx id,5%dropγeffPU140S2intemediate– 55%vtxid(fromtimingforγ)S2optimistic– 75%vtxid(fromtimingforγ andchargedptcls)


H→ZZ

Expected uncertainty0 0.2 0.4 0.6 0.8

(13 TeV)-13000 fbCMS Projection

l 4→ ZZ* →H

ZZµ 0.07 (theo.)± 0.04 (exp.) ± 0.02 (stat.) ± 0.03 (theo.)± 0.03 (exp.) ± 0.02 (stat.) ±

ZZggHµ

ZZVBFµ

ZZVHµ

ZZttHµ

ECFA16 S1+ ECFA16 S2+

Expected uncertainty0 0.2 0.4 0.6 0.8


l 4→ ZZ* →H

ZZµ 0.07 (theo.)± 0.07 (exp.) ± 0.05 (stat.) ± 0.04 (theo.)± 0.04 (exp.) ± 0.05 (stat.) ±

ZZggHµ

ZZVBFµ

ZZVHµ

ZZttHµ

ECFA16 S1 ECFA16 S2

Projectfrom2016analysiswith12.9fb-1 CMS-PAS-HIG-16-033

Uncertainties: integratedL(1.5%),leptonID(1%)

Projections:- TheoryplaysimportantroleinggH- Forthesubleading productionmodes,theuncertaintiesaredominatedbythestatisticalcomponent- At3000fb−1,theexperimentalsystematicsuncertainties(dominatedbyluminosity,JES,andleptonefficiencies)areslightlyconstrained,duetonatureofthefit.


ds(H→ZZ)/dpT

(H) [

fb/G

eV]

T/d

pfid

σd

4−10

3−10

2−10

1−10

1


(H)>

200

GeV

)T

(pσ

501

sys. unc.)⊕Toy Data (stat.Systematic uncertainty (ECFA16 S1+)Systematic uncertainty (ECFA16 S2+)

H (POWHEG+JHUGen) + XH→ggXH = VBF + VH + ttH

(H) [GeV]T

p0 50 100 150 200 250

Ratio

to P

OW

HEG

0.70.80.9

11.11.21.3

(H) [

fb/G

eV]

T/d

pfid

σd

4−10

3−10

2−10

1−10

1


(H)>

200

GeV

)T

(pσ

501

sys. unc.)⊕Toy Data (stat.Systematic uncertainty (ECFA16 S1)Systematic uncertainty (ECFA16 S2)

H (POWHEG+JHUGen) + XH→ggXH = VBF + VH + ttH

(H) [GeV]T

p0 50 100 150 200 250

Ratio

to P

OW

HEG

0.70.80.9

11.11.21.3

Inthismeasurement,thetheoreticalun- certaintiesinthetotalsignalcrosssectionarenotrelevantandthecrosssectionismeasuredinafiducialphasespacecloselymatchingtheexperimentalacceptance

Resultsofprojections:

highpT region(pT >200GeV)isstilldominatedbythestatisticaluncertaintyat3000fb−1.- 10to29%(4to9%)for300(3000)fb−1.9/8/17 V.Rekovic,LHCUpradePhysicsinCMS 19

H→ZZanomalouscoupling

• Anomalouscontributionsinthespin-0tensorstructureofHZZinteractionscanbecharacterizedbycoefficientsa2,a3,Λ1,andΛQ(arXiv:1411.3441)

• Onlytensorstructuresproportionaltoa2,a3andΛ1areobservableusingon-shellHbosondecay.

• Sincethemeasurementisstatisticallylimited,onlyscenariosS1andS1+,wherethesystematicuncertaintiesareunchangedwithrespecttothereferenceanalysis,areshown. Expected 95% CL limits

0.2− 0.15− 0.1− 0.05− 0 0.05 0.1 0.15 0.2

Projection CMS

Expected limits onHiggs Boson anomalous couplings

l 4→ ZZ* →H = 125 GeVHm

ZZa3fZZa2fZZ

1Λf

)-1ECFA16 S1 (300fb

)-1ECFA16 S1+ (3000fb

(13 TeV)


H→μμ

H → μ μ

Excl. limit

• The decay H→μμ can be observed with a significance of 5 sigma

• measurement of the Hμμ coupling with a precision of ~10%

H → μ μ

Signal significance

• Ongoing analysis with Run II data


H→cc

G.Salam,A.Weiler9/8/17 V.Rekovic,LHCUpradePhysicsinCMS 22

SMHiggsbosonpair-production

LO at 14 TeV

Takenfrom“Higgsself-couplingmeasurementsattheLHC” byM.J.Dolan,C.EnglertandM.Spannowsky,JHEP10(2012112.Many channels to investigate.

Most promising ones:

bƃW+W- (large BR but large bkg.)

bƃγγ (clean but small BR)

bƃτ+τ-

bƃμ+μ- also being consideredbƃbƃbƃ2l2ν

NNLO cross-section at mH=125 GeV:σ = 40 ± 3 fb G. de Florian, J. Mazzitelli, 1309.6594

λHHH

Destructive interference between the two diagrams

–


di-Higgsproductionwith 3000fb-1At HL-LHC with L=3000 fb-1 we will produce ~120000 HH events

bƃW+W- ~14000 evtbƃγγ ~ 150 evtbƃτ+τ- ~ 4300 evtbƃ2l2ν ~ 730 evt

However we pay a big pricein BR’s …


di-Higgsproduction@13TeV with 2.7fb-1Example: HH→bƃγγ: CMS-PAS-HIG-16-032 2DfitM(γγ)xM(bb)

M(jj) [GeV]80 90 100 110 120 130 140 150 160 170 180 190 200

Dat

a/M

C

0.51

1.5

Even

ts/(3

.0 G

eV)

2−10

1−10

1

10

210

310

410

510

CMS Preliminary (13 TeV)-1L = 2.70 fb

)-1 Data (2.70 fb

Stat. Uncertainty

)γγ VBF H(

)γγ VH(

)γγ ggH(

)γγ ttH(

+Jets/jj+Jetsγ j

+Jetsγγ

= 300 GeVX Graviton M

= 600 GeVX Radion M

SM Nonresonant HH

) [GeV]γγM(100 110 120 130 140 150 160 170 180

Dat

a/M

C

0.51

1.5

Even

ts/(1

.0 G

eV)

2−10

1−10

1

10

210

310

410

510

CMS Preliminary (13 TeV)-1L = 2.70 fb

)-1 Data (2.70 fb

Stat. Uncertainty

)γγ VBF H(

)γγ VH(

)γγ ggH(

)γγ ttH(

+Jets/jj+Jetsγ j

+Jetsγγ

= 300 GeVX Graviton M

= 600 GeVX Radion M

SM Nonresonant HH

SignificantbackgroundfromSMHiggs


SMH→HHprojections

expected uncertainty2− 1− 0 1 2 3 4 5

bbbbµ

VVbbµ

bbττµ

bbγγµ

ECFA16 S2 ECFA16 S2+Stat. Only

= 13 TeVs Projection CMS HH→SM gg

bƃγγγ efficienciesanduncertaintiesaretreatedinthesamewayasfortheH→γγ.90%ofthephotonscomingfromHHdecaysarecentral,neglectdegradationofphotonefficiencyintheforwardregion

bƃτ+τ-

- current uncertainty of tt shape prediction is scaled down by a factor three to match the the estimated fraction of jets faking τleptons at the HL-LHC. - QCD multijet (subdominant background) obtained from data and therefore the statistical uncertainty is assumed to be negligible. - μ, e and τh uncertainties are assumed to be that of 2015 analysis.

bƃW+W-

Mainbackgrounds,tt andDrell-Yanprocesses,areexpectedtobeestimatedfromdataandthereforetheiruncertaintiesareconsidered

bƃbƃMainbackground,QCDmultijetproduction,isestimatedfromdata.anditsuncertaintyisscaleddownwiththeintegratedluminosityintheprojection.Theuncertaintiesinthepredictionsoftheotherbackgroundsareassumedtobeunchangedwithrespecttothe2015analysis.

projectfromRunII(2015data2.3to2.7fb-1)


SMX→HHConsiderradion for3differentmasses,measureexpectedlimitsoncrosssection,andderivemassscaleLR (theultravioletcutoffofthemodel)atwhichtheradion isexcluded.


MSSMφ→ττ

(GeV)φm210 310

(pb)

)ττ→φ(

B⋅)φ(g

gσ

95%

CL

limit

on

3−10

2−10

1−10

1

10

210

310

Projections)-1Scenario 1 (300 fb)-1Scenario 2 (300 fb

)-1Stat. Only (300 fb)-1Scenario 1 (3000 fb)-1Scenario 2 (3000 fb

)-1Stat. Only (3000 fb

)-1HIG-16-006 (2.3 fb

Expected

Expectedσ1±

Expectedσ2±




CMS Projection (13 TeV)ττ→φMSSM

(GeV)φm210 310

(pb)

)ττ→φ(

B⋅)φ(b

bσ

95%

CL

limit

on

4−10

3−10

2−10

1−10

1

10

210

310Projections

)-1Scenario 1 (300 fb)-1Scenario 2 (300 fb



)-1HIG-16-006 (2.3 fb

Expected

Expectedσ1±

Expectedσ2±




CMS Projection (13 TeV)ττ→φMSSM 95% CL Expected exclusion: Projections:

13 TeV Expected (HIG-16-006) )-1 Scenario 1 (300 fb )-1 Scenario 1 (3000 fb

Expectedσ 1± )-1 Scenario 2 (300 fb )-1 Scenario 2 (3000 fb

Expectedσ 2± )-1 Stat. Only (300 fb )-1 Stat. Only (3000 fb

CMS Projection (13 TeV)ττ→φMSSM

(GeV)Am200 400 600 800 1000 1200 1400 1600 1800 2000

βta

n

10

20

30

40

50

60 scenariomod+

hm

Finalstatesofthetwoτ leptons:μτh,eτh,τhτh andeμ.Background:Drell-Yan(dominant)withadecaytoτ leptonpairs, W+jets,tt,andQCDmultijet

“model-independent”:searchforsingleresonancesignalforaHiggsbosonM[90GeV,3.2TeV,]anddecayingintoτ leptons

“model-dependent”limitissetasafunctionofmA andtanβinaparticularMSSMbenchmarkscenario,combiningthepredictionfrombothproductionmodesandallthreeneutralHiggsbosons


Conclusions

• Theexperiencegainedandon-trackupgradesprogramsuggestthatCMSexperimentwillmeetthephysicsexpectationatHL-LHCwith3000fb-1,@√s=14TeV andinstantaneousluminositiesof5x1034cm-2 s-1

• VeryrichHiggsprogramavailablewiththeupgradedCMSdetectorforthenext20yearsdespiteveryharshconditions(highradiation,highpile-up)– Higgsbosoncouplingscanbemeasuredwithfewpercentprecision– 1-4 % statistical, experimental– 3-7%theory- wouldbegreatifcanimproveto1%level (callforhelpfromtheorycommunity)

– rare Higgs boson decays can be probed– Higgs self-coupling studies possible


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