SUSY SEARCHES AT LHC MARÍA TERESA DOVA ON BEHALF OF ATLAS & CMS IX Latin American Symposium on High Energy Physics SILAFAE 2012, Sao Paulo, Brazil

IMPOSSIBLE TO COVER EVERYTHING!

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All papers and public notes: https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsSUS https://twiki.cern.ch/twiki/bin/view/AtlasPublic/SupersymmetryPublicResults

With thanks to the ATLAS and CMS SUSY convenors

SUSY FRAMEWORK M

T D

ova

IFLP

-UN

LP, L

a P

lata

Arg

enti

na

3

T. R

izzo

(SLA

C, 0

1-Au

g-12

)

Why believe in SUSY? o  Light Higgs: need new physics to stabilize mass. o  Dark matter: strong evidence from astrophysics (R-parity conservation, neutral light LSP) Goal: find hints of SUSY particles in 0.1–few TeV range

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SUSY CROSS SECTION & MASS SPECTRUM

Strong production

A“natural” SUSY spectrum

Higgs sector & gauginos: light

First 2 generations Squarks : heavy

Direct stop/ sbottom production

EW production of

Stop (sbottom): light

SUSY ANALYSIS

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1. Event selection cuts and definition of signal regions: - Cut in a set of variables that can discriminate between signal and backgrounds. 2. Background determination: -  QCD and fake backgrounds: estimate from data -  top, W/Z+jets: estimate from data when possible or with transfer factors using background-enhaced control regions

- Smaller irreducible background using MC 3. Estimate all uncertainties: - Experimental uncertainties: jet energy scale calibration, b-tagging eff…. - Theoretical uncertainties: renormalisation and factorisation scales, PDF…. 4. Look into the signal region: Excess in data? If not, derive exclusion limits 5. Interpretation

STRONG PRODUCTION IN RPC Ø  Lightest sparticle (LSP) stable (WIMP candidate) Ø  Pair produced sparticles Ø  Cascade decay down to the LSP

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Inclusive jets + ETmiss + X

X= γ, ℓ,more jets... depending on NLSP

1-lepton

2-lepton

0-lepton

ATLAS 0-LEPTON + JETS + ETmiss

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§  m1/2<350 GeV excluded for all values of m0; m1/2<740 GeV for low values of m0 §  Squark and Gluino masses below 1.5 TeV

8 TeV §  0-l , 6-9 Jets §  0-l , 2-6 Jets

Reported here

SRB: 3Jets

CMS JET + HTmiss ANALYSIS

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Interpretation in simplified models with only gluinos or squarks production

for m( ) <200 GeV

m( g)<1m( q)< 0.76

TeV TeV

0-lepton, ≥3 jets generic SUSY search.

(pb

)σ

95%

C.L

. upp

er li

mit

on

-310

-210

-110

1

10

(GeV)gluinom400 600 800 1000 1200 1400

(G

eV)

LSP

m

0

200

400

600

800

1000 exp.σ1 ±Expected Limit

theoryσ1 ± NLO+NLLσ = 8 TeVs, -1CMS Preliminary, 11.7 fb

)g~)>>m(t~; m(10χ∼ t t → g~, g~ g~ →pp

(GeV)TH300 400 500 600 700 800 900

Even

ts /

bin

-110

1

10

210

310 = 8 TeVs, -1CMS Preliminary, 11.7 fb 3)≤

jj

= 2; nbb

Data (hadronic sample, n Expected Unc. ±Standard Model

= 100 GeV)

1

0χ∼

= 550 GeV, mb~

(m10χ∼ b → b~, b~ b~ →SM + pp

CMS ANALYSIS

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αT

Interpretation in SMS

Requiring exactly 2 b-jets per event

8 TeV

α_T

≥2 jets with b-jets

ATLAS 1-LEPTON ANALYSIS Signal region with exactly one lepton (e or µ), ≥4 jets and ET

miss

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8 TeV

In mSUGRA limit on squark and gluino masses (<1.24 TeV) improved by about 100 GeV with respect to 7 TeV analysis

§  MSSM-gluinos are strongly interacting Majorana fermions.

§  Same sign leptons from the two legs in 50% of the cases + jets + ETmiss

§  The requirement of SS leptons suppresses the contribution from SM processes and thus enhances the potential SUSY signal significance.

ATLAS 2-LEPTON SS ANALYSIS

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8 TeV

Competitive at high m0 where gluino production dominates

THIRD-GENERATION SQUARKS

Naturalness requires : •  stop and sbottoms

up to 600 GeV. •  Gluinos up to

1.5 TeV.

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ü Direct production: bs, Ws, ts, ETmiss

ü Gluino mediated: : bs, Ws, ts, Etmiss, jets

CMS DIRECT SBOTTOM

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Direct production : short cascade

Direct production : long cascade

Large ETmiss

≥2 jets, b-tagged jets SR: HT, Nj(2-3), Nb-jets(1-2)

Same sign dilepton with at least 2 b-tagged jets.

SR: lepton charges, ETmiss, HT, Nb-jets

8 TeV

Very light stop

ATLAS DIRECT SCALAR TOP

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Light stop Scalar top mass below or around top quark mass

à1(2) leptons, b-jets, jets, ETmiss

106 GeV

àsoft dilepton + jets + ETmiss

[GeV]T2m0 20 40 60 80 100 120 140 160 180 200

Even

ts /

5 G

eV

-110

1

10

210

310

410

ATLAS

(b) different-flavour

= 7 TeVs -1L dt = 4.7 fb∫

Data 2011SM BackgroundZ+jetstt

WW+ZZ+WZFake leptons

Z+WttW+ttt) = (300,50) GeV

10χ∼,1t

~m(m(T,A) = (450,100) GeV

[GeV]T2m0 20 40 60 80 100 120 140 160 180 200

Dat

a/M

C

00.5

11.5

2

≥

Medium stop

ATLAS DIRECT SCALAR TOP

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Heavy stop

à2 leptons (ee, eµ, µµ), ETmiss

Discriminating variable mT2

Look for hadronic or leptonic top decays with extra ET

miss

à1 lepton, ≥ 4 jets (1b-jet)

ET m

iss >40 GeV

FINAL RESULTS FOR STOP PAIR PRODUCTION SEARCHES AT 7 TeV (4.7 fb-1 )

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ATLAS GLUINO MEDIATED

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8 TeV Gtt simplified models

) GeVg~m(300 400 500 600 700 800 900 1000 1100

) GeV

1b~m

(

200300400500600700800900

10001100

σ 1 ± NLO+NLLσ = prodσObserved Limit σ 1 stat. ±Expected Limit

-1 = 10.5 fbint

= 8 TeV, LsCMS Preliminary, Model B2

) = 50 GeV10χ∼m(

) = 300 GeV+1χ∼m(

CMS SBOTTOM FROM GLUINOS

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Exclusion (95% C.L.) for different choices of the chargino mass.

2 SS leptons and ≥2 b-jets

) GeVg~m(300 400 500 600 700 800 900 1000 1100

) GeV

1b~m

(

200300400500600700800900

10001100

σ 1 ± NLO+NLLσ = prodσObserved Limit σ 1 stat. ±Expected Limit

-1 = 10.5 fbint

= 8 TeV, LsCMS Preliminary, Model B2

) = 50 GeV10χ∼m(

) = 150 GeV+1χ∼m(Interpretation in

several SMS

8 TeV

ELECTROWEAK PRODUCTION OF SUSY PARTICLES

ü  Weak production could be the dominant production at this stage. ü  Models with decays into sleptons/W, Z. ü  Signatures with multiple charged leptons.

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[GeV]-l+lM0 20 40 60 80 100 120 140 160 180 200

[G

eV

]T

M

0

50

100

150

200

250e

±

e±eµ

±

e±ee

±

µ±µµ

±

µ±µ

e

±

e±eµ

±

e±ee

±

µ±µµ

±

µ±µ

CMS Preliminary -1 = 9.2 fbint = 8 TeV, Ls

CMS EWK PRODUCTION:

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3 leptons + ETmiss: MT & M(ll)

2leptons + dijet + ETmiss

Depending on the mass sppliting, signal may show up in one of the search regions.

-1 = 9.2 fbint

= 8 TeV, LsCMS Preliminary

[GeV]missTE

50 100 150 200

even

ts / 5

0 G

eV

01234567

[GeV]missTE

50 100 150 200

even

ts / 5

0 G

eV

0

1

2

3

4

5

[GeV]missTE

50 100 150 200

even

ts / 5

0 G

eV

0

0.5

1

1.5

2

2.5

[GeV]missTE

50 100 150 200

even

ts / 5

0 G

eV

0

1

2

3

4

5

[GeV]missTE

50 100 150 200

even

ts / 5

0 G

eV

02468

10121416

[GeV]missTE

50 100 150 200

even

ts / 5

0 G

eV

00.5

11.5

22.5

33.5

44.5

[GeV]missTE

50 100 150 200

even

ts / 5

0 G

eV

010203040506070

[GeV]missTE

50 100 150 200

even

ts / 5

0 G

eV

050

100150200250300350400

[GeV]missTE

50 100 150 200

even

ts / 5

0 G

eV

0

5

10

15

20

25

>160

GeV

TM

<75 GeV-l+lM <105 GeV-l+l75 GeV<M >105 GeV-l+lM

<160

GeV

T12

0 G

eV<M

<120

GeV

TM

Channels:e

±

e±eµ

±

e±ee

±

µ±µµ

±

µ±µ

DataZZ

*γZWZNon-promptRare SM

uncertaintyTotal bkg

[GeV]missTE

0 50 100 150 200 250

entrie

s / 10

GeV

-210

-110

1

10

210

310

410 data

Z+jets

Flavor Symmetric

WZ+ZZ

Rare SM

CMS Preliminary-1 = 9.2 fbint = 8 TeV, Ls

eventsµµee/

ratio

0

1

2

SRs

CMS WEAKLY PRODUCED SUSY

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Limits on chargino-neutralino in SMS, extended and improved from 2011 paper

8 TeV

ATLAS EWK PRODUCTION: SLEPTONS 2 leptons + ET

miss Reduce the WW background by using its endpoint in tranverse mass: mT2 (at ~90 GeV)

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Limits on sleptons- pMSSM

PHOTONS + ETmiss à GMSB SCENARIOS

Depending on the nature of NLSP, different experimental signatures.

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Photons provide a clean experimental signature, reconstructed with high purity and efficiency.

GGM (General Gauge Mediation)

CMS γ + JET + ETmiss

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Wino-like

Bino-like

8 TeV

ATLAS γγ + ETmiss

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Total visible transverse energy

Simplified models: •  Gluino/squarks for production •  Bino-like neutralino as NLSP •  Gravitino

3 SR: ETmiss, HT, Δφ(γ, ET

miss )

General Gauge Mediation (GGM)

ATLAS γ + b + ETmiss

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Selection

Ø R-parity Violation: Lifetime proportional to λ2, λ’2, λ”2

Displaced vertex if λ, λ’, λ” <10-7

Ø  A long-lived (LL) can also be produced in RPC •  ~100 MeV (e.g, AMSB) à disappearing track •  Heavy LLP: sleptons, squarks, gluinos (R-hadrons)

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RPV & LONG-LIVED SPARTICLES

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Long-lived AMSB charginos via EW processes

ATLAS CHARGINO DISAPPEARING TRACK

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ü  Jet (from ISR) + ETmiss

ü  earch for high-pT isolated tracks that stop in outer TRT. ü  Model independent results.

àBR set to 100%

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Multileptons provide sensitivity to several new physics models

CMS RPV SEARCH

8 TeV

CONCLUSIONS (I): SUMMARY CMS

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[GeV]0m500 1000 1500 2000 2500 3000

[GeV

]1/

2m

100

200

300

400

500

600

700

800

± l~ LEP2

± 1χ∼ LEP2

No EWSBNon-Convergent RGE's

= L

SP

τ∼

) = 500g~m(

) = 1000g~m(

) = 1500g~m(

) = 1000q~m(

) = 1500q~m(

) = 2000

q~m

( ) = 2500

q ~m

( )=10βtan( = 0 GeV0A

> 0µ

= 173.2 GeVtm

= 7 TeVs, -1 = 4.98 fbint

CMS Preliminary L

Tα

Jets+MHT

Razor

SS Dilepton

OS Dilepton

Multi-Lepton

MT2

1 Lepton

4.98 fb -1 , 7 TeV Best analysis result per topology

CONCLUSIONS (II): SUMMARY ATLAS

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1 TeV

CONCLUSIONS

Ø  ATLAS and CMS have produced an impressive number of papers and conference notes using data from 7 TeV and 8 TeV collisions.

Ø  Probed a wide variety of SUSY motivated final states: SUSY was not “just around the corner”…

Ø  Analysis at 8 TeV data are in progress. Expected ~20fb-1. More to follow!

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THANKS!

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BACKUP SLIDES

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OS mass edge search

Generic OS search

- Dileptons with large hadronic activity and MET

- Varios signal regions define in ETMiss-HT plane

Search for kinematic edges in lepton pair inv. mass (SF)

Limits depending on mass edge position (mmax) HT>300 GeV

ETMiss>150 GeV

CMS OS DI-LEPTON

ATLAS γ + LEPTON+ MET

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-  Gluinos masses < 619GeV excluded at 95% CL for any m_wino < excluded m_ gluino -  Wino masses < 221GeV excluded at 95% CL for any value of the gluino mass.

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