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([email protected])
TerukiTeruki KamonKamon Tasks at a GlanceTasks at a GlanceSignSign--up!!!up!!!
TerukiTeruki KamonKamonTexas A&M/LPCTexas A&M/LPC
(([email protected]@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
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Introduction toHigh Energy Physics
by D H Perkins
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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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Teruki Kamon J Term III : LPC Jets + MET Topology Group 7[GeV] )(bbM [GeV] )( jjbMD
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. Univ. of Michigan, Jan. 7, 2009
A SUSY Excess A SUSY Excess –– Not Discovery Not Discovery 103
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∑+/= 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