CCollider ollider SScene cene IInvestigationnvestigationgg

CSI: Jets + METTHE SECOND SEASON

G l ith CMSG l ith CMSAnwar Anwar BhattiBhattiR k f llR k f ll Goal with CMSGoal with CMS

Why Why Jets+METJets+MET??σσBSMBSM ~ 50 ~ 50 pbpb

RockefellerRockefeller(bhatti@fnal.gov)

TerukiTeruki KamonKamon Tasks at a GlanceTasks at a GlanceSignSign--up!!!up!!!

TerukiTeruki KamonKamonTexas A&M/LPCTexas A&M/LPC

((tt--kamon@tamu.edukamon@tamu.edu) )

Physics with Physics with Jets+METJets+MET TopologyTopology1January 14, 2009

Goals of Goals of Jets+METJets+MET Topology GroupTopology Grouphttp://uscms.org/uscms_at_work/physics/lpc/organization/topologies/jets_met/index.shtml

The CMS SUSY and EXOTICA groups have a set ofNov. 18, 2007Nov. 18, 2007

vigorous programs to discover new particle(s). The LPCJets+MET topology group will help such CMS programs inthe following final states:the following final states:

ETmiss + Jets

ETmiss + Jets + τ's

ETmiss + Jets + b's (e.g., h→bb)

ETmiss + Jets + t's (e.g., gluino → tt + neutralino)

…As a group, we will actively involved in various common tasks such as τID, b tagging, and missing ET clean-up/calculation/correction in theCMS SUSYSUSY and EXOTICAEXOTICA gro ps to ma imi e the s ccess of the CMSCMS SUSYSUSY and EXOTICAEXOTICA groups to maximize the success of the CMSnew particle hunting in the initial conditions up to 1 fb-1 for now. Thisobviously also leads us to make strong connections with DijetDijet topologyy g jj p gygroup and τ/b object groups. ...

Teruki Kamon J Term III : LPC Jets + MET Topology Group 2

Start with “Running” CouplingsStart with “Running” Couplingse.g., QCD

)/log()2(1112)( 22

2

Λπα

QnnQ

flavorcolors −

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Introduction toHigh Energy Physics

by D H Perkins

)g()( Qflavorcolor

nf = 6 (quark flavors); n = 3 (colors)

by D. H. Perkins

nf 6 (quark flavors); nc 3 (colors)

αsThe Nobel Prize in Physics 2004

Q2 (GeV2)Teruki Kamon J Term III : LPC Jets + MET Topology Group 3

A Hint of BeyondA Hint of Beyond--SM at SM at TeraTera--scalescale

SM + SUSYSM

log10(Energy)log10(Energy)

MMSUSYSUSY ~ 500~ 500--3000 3000 GeVGeV//cc22

andand twotwo (and only two)(and only two)

g10( gy)g10( gy)mm1/21/2

and and twotwo (and only two) (and only two) Higgs doubletsHiggs doublets mm00

Teruki Kamon J Term III : LPC Jets + MET Topology Group 4Image of a GUT world by Abram Krislock

WWhy hy Jets+METJets+MET at the LHC?at the LHC?E l SSUSSY ii h R ii CC iiEExxaammppllee:: SSUUSSYY wwiitthh RR--ppaarriittyy CCoonnsseerrvvaattiioonn

g~g~ , q~g~ , or q~q~ production will be dominant, followedgg , qg , qq p ,by their decays (e.g., 0

2χ~qq~→ ). → JJeettss R parity conservation p y

Stable lightest supersymmetric particle (LSP)

If LSP is the lightest neutralino ( 0χ~ ) If LSP is the lightest neutralino ( 1χ ), • it will escape the detector → MMEETT (( TE/ ))

0~ C ld D k M tt did t → CC ll• 01χ = Cold Dark Matter candidate → CCoossmmoollooggyy

Thus, the evidence of SUSY-like new physics will appearin the Jets+MET final statesin the Jets+MET final states.

CCoossmmoollooggyy ++ LLHHCC = [Exciting Motivation]++ [Right Place&Timing]

Teruki Kamon J Term III : LPC Jets + MET Topology Group 5

[Exciting Motivation]+ [Right Place&Timing]

Particle Physics Particle Physics ++ CosmologyCosmology

CBS comedy “Big Bang Theory”(Season 2 Episode 5, Oct 20, 2008)

+ + CosmologyCosmology

( p , , )

Teruki Kamon J Term III : LPC Jets + MET Topology Group 6

Jets+MET+Jets+MET+XX in SUSYin SUSYJets+MET+Jets+MET+XX in SUSYin SUSYOO B h llB h ll CMS Ph i D J l 23 2008CMS Ph i D J l 23 2008

hep-ph/060312801

02 χττττχ ~~~ mm ±± →→

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O. O. BuchmullerBuchmuller, CMS Physics Days, July 23, 2008, CMS Physics Days, July 23, 2008

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6 ))()(( 1χlljjbjjb→T. Kamon, Talk at“The LHC and Dark Matter”U i f Mi hi

Teruki Kamon J Term III : LPC Jets + MET Topology Group 7[GeV] )(bbM [GeV] )( jjbMD

0 co

Phys

. Univ. of Michigan, Jan. 7, 2009

A SUSY Excess A SUSY Excess –– Not Discovery Not Discovery 103

00 p

b-1

103

102

Background

0 G

eV/1

0

10 q~GeV 600SUSY

Even

ts/5

1

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10-1

[GeV] )(4

∑+/= i,TTeff EEM

[Stage 1] Is this a real excess? We need to understand MET.Detector Performance Group or DPG (especially, HCAL)

∑i

,ff

p ( p y )Physics Object Group or POG (especially, jets, MET, tau, b) Physics Analysis Group or PAG (especially, SUSY and EXOTICA)

[Stage 2] What kind of excess? We need to identify e, µ, τ, b, t.g y µPOGPAG (especially, Kinematical reconstructions)

Teruki Kamon J Term III : LPC Jets + MET Topology Group 8

““SupersymmetristsSupersymmetrists, Beware!” (J. Ellis, SUSY07), Beware!” (J. Ellis, SUSY07)

CERN-TH.3968/84

Experimental Observation of Events with LargeLargeMissingMissing TransverseTransverse EnergyEnergy Accompanied By a Jet

CERN-EP/84-4229 March 1984

IS SUPERSYMMETRY FOUND?IS SUPERSYMMETRY FOUND?

MissingMissing TransverseTransverse EnergyEnergy Accompanied By a Jetor Photon(s) in ppbar Collisions at /s = 540 GeV

(submitted to Phys. Lett. B)

Teruki Kamon J Term III : LPC Jets + MET Topology Group 9

TTypical Statistics at 10 ypical Statistics at 10 TeVTeV // L L = 10 pb= 10 pb--11

(*)Assume L = 10 pb-1, include acceptance,initial reconstruction and ID efficiency

Mi i bi 1012Minimum bias 1012 Jet, ET > 25 GeV 3 x 1010 1 1 mmbb

roto

n)ro

ton) Jet, ET > 140 GeV 3 x 106

γ+Jet E > 20 GeV 3 x 1061 1 µµbb

prot

onpr

oton

--pp γ+Jet, ET > 20 GeV 3 x 10 30,000

llZνl→W1 1 nnbb

σσ(p(p 3,000

100qtt 4νl→ll→Z

1 1 pbpb

(TeV) s

Nailing DownNailing Down σσBSMBSM = 50 = 50 pbpb in 1 ~ 1000 pbin 1 ~ 1000 pb--11

LL NNprodprod(events)(events)

AAtotaltotal~ 10%~ 10%

…Many people are working on Detectors & Physics Objects.Major Major Effort & Effort & PapersPapers Trigger/DPG/POG/TopologyTrigger/DPG/POG/Topology

1 pb-1 50 5 Commissioning αT, MET,  and  HCAL operationp g TMeff using QCD events

pTrigger menuHigh‐quality jet objectsHigh‐quality e/µ rejection

10 pb-1 500 50 Understanding αT, MET,  and Meff using Z(→ll)+jets, 

High‐quality τ IDHigh‐quality b taggingHigh‐quality γ ID

W(→lν)+jets, γ+jet & tt

(*)(*) ααTT in QCD eventsin QCD eventsHigh‐quality MET/CleanupBasic selection cuts & SUSY‐PAT

(*) (*) W+jetsW+jets, , Z+jetsZ+jets, , tt+jetstt+jets(*) (*) Search for SUSY …Search for SUSY …

100 pb-1 5,000 500 Retuning αT, MET, and Meffi Z j W j j &using Z+jets, W+jets, γ+jet & 

tt+jets

MET scale using Z W lνhZ µτττ →→

MET  scale using Z→ττ, W→lν

(*) (*) W+jetsW+jets, , Z+jetsZ+jets, , tt+jettt+jet(*)(*) EvidenceEvidence for SUSYfor SUSY( ) ( ) Evidence Evidence for SUSY …for SUSY …

1 fb-1 50,000 5,000 (*) (*) ObservationObservation of of SUSY SUSY ……

Teruki Kamon J Term III : LPC Jets + MET Topology Group 11

TTasks at a Glanceasks at a Glance(1) QCD & EWK – dominant backgrounds for new physics

QCD smearing function (ElifElif, Taylan, …)αT for QCD rejection (Mehmet, Taylan, …)T Q j ( , y , )MET using W/Z/γ +jets (SueSue AnnAnn, …)MET using Z(→ νν ) + jets (JimJim, …)MET using tt + jets (DuongDuong, …)

Names in red arespeakers in ourparallel sessionMET using tt + jets (DuongDuong, …)

Tau ID using Z→ ττ (AlfredoAlfredo, …)

(2) Detector commissioning effort from SUSY view pointMET DQM (K )MET DQM (Ken, …)MET cleanup (Alfredo, Ming, Michael, … by HCAL ROC team)MET monitoring trigger for HPD noise study (Alfredo at HCAL-DPG)MET Triggers (JimJim, …)MET in CRAFT (MehmetMehmet, …)

(3) Preparing analysis tool for all-hadronic final states(3) P epa ng analys s tool fo all had on c f nal statesSUSY b’s (HaroldHarold, …), τ’s (JonathanJonathan, …), W’s (…)Black Hole High multiplicity high-ET jets (Romulus, …)

(4) Earl SUSY related paper(s) sing α in n jet final states(4) Early SUSY-related paper(s) using αT in n-jet final states(5) More …

Teruki Kamon J Term III : LPC Jets + MET Topology Group 12

Summary Summary : : EE = = MMCC22

EEff MM CCh ll CCEEffort = MManpower x CChallenge x CCreativity√s = 10 TeV & L = 50 pb−1

ill f l f BSM h

METMET--independent Analysisindependent Analysis

– still powerful for BSM searches –

eV)

NNeventevent @ 1 fb@ 1 fb−−11

LM1LM1 ~400~400

αT

m1/

2(G

e

LM1LM1 400400

ZZ,,WW, top, top ~80~80

QCDQCD ~0~0

m

** ☺☺

Tevatronm0 (GeV)

Tevatron LHC 2009 (50 pb−1@10 TeV)Teruki Kamon J Term III : LPC Jets + MET Topology Group 13