[PPT] - ATLAS Searches for SUSY Chris Young, CERN ATLAS Group What have we PowerPoint Presentation

SLIDE 1

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group What have we not looked for? 1 / 37

SLIDE 2

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group What have we not looked for? 2 / 37

SLIDE 3

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group This talk: Where/What have we looked for? 3 / 37

SLIDE 4

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Outline

◮ Introduction ◮ Searches for strong production (RPC) ◮ Searches for stop/sbottom production (RPC) ◮ Searches for electo-weak production (RPC) ◮ Searches for RPV SUSY. ◮ Conclusions

4 / 37

SLIDE 5

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Introduction

◮ There are searches for both RPC and RPV SUSY (although many more

RPC).

◮ Experimentally we divide our searches into 3 categories driven by the

production mode.

◮ This is motivated by the very different signatures that result from the

decays.

10

3

10

2

10

1

1 10 200 400 600 800 1000 1200 1400 1600

ν ˜eν ˜e* l ˜el ˜e* t ˜1t ˜1* q ˜q ˜ q ˜q ˜* g ˜g ˜ q ˜g ˜ χ ˜ 2

g

˜ χ ˜ 2

χ

˜ 1

+

maverage [GeV] σtot[pb]: pp → SUSY √S = 8 TeV

5 / 37

SLIDE 6

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Searches For Strong Production (RPC)

◮ Strong production has the highest cross-section at a p-p collider →

highest mass reach.

◮ For RPC SUSY we assume to have a neutralino (or gravitino) LSP such

that there will be E miss

T

◮ Strong decays will produce jets and then searches are split by the number

f leptons also required.

◮ Most searches favour a strategy of cutting hard on the sum of transverse

momenta of objects meff and E miss

T

to reduce the SM backgrounds.1

◮ Background determination is then performed by performing a

simultaneous fit in “control regions” which are rich in different SM background with similar kinematic cuts and the “signal region(s)”. Monte-Carlo is used to evaluate the ratios between regions.

◮ Fits are performed both for the background only hypothesis and for each

point in the models used for interpretation such that signal contamination in the “control regions” is taken into account.

1There are some exceptions to this.

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SLIDE 7

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Strong Production (RPC) : 0-lepton + ≥2-6 jets

ATLAS-CONF-2013-047

◮ Hard cuts on scalar sum of jets and E miss

T

(meff) and E miss

T

/meff.

◮ 10 signal regions covering a variety of jet multiplicities.

7 / 37

SLIDE 8

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Strong Production (RPC) : 0-lepton + ≥2-6 jets

ATLAS-CONF-2013-047

◮ Background estimation comes from “control regions” which require a

lepton and require/veto the presence of a b-jet (for t¯ t and W +jets) or a high pT photon (for Z+jets).

◮ The Monte-Carlo is seen to describe the data well in these regions and a

simultaneous fit gives the expectation in the SR.

(incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000 events / 100 GeV 1 10

2

10

3

10

1

L dt = 20.3 fb

∫

= 8 TeV) s Data 2012 ( SM Total W+jets & single top t t Z+jets Diboson Preliminary ATLAS CRWC - 4 jets Cm Ct

(incl.) [GeV]

eff

m

500 1000 1500 2000 2500 3000 3500 4000

DATA / MC

0.5 1 1.5 2 2.5

(incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000 events / 100 GeV 1 10

2

10

3

10

1

L dt = 20.3 fb

∫

= 8 TeV) s Data 2012 ( SM Total W+jets & single top t t Z+jets Diboson Preliminary ATLAS CRTC - 4 jets Cm Ct

(incl.) [GeV]

eff

m

500 1000 1500 2000 2500 3000 3500 4000

DATA / MC

0.5 1 1.5 2 2.5

(incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000 events / 100 GeV 1 10

2

10

3

10

4

10

1

L dt = 20.3 fb

∫

= 8 TeV) s Data 2012 ( SM Total +jets γ Multijet W+jets & single top t t Diboson Preliminary ATLAS CRYC - 4 jets

) > 0.25

jets

(N

eff

/m

miss T

after cut: E

Ct Ct

(incl.) [GeV]

eff

m

500 1000 1500 2000 2500 3000 3500 4000

DATA / MC

0.5 1 1.5 2 2.5

8 / 37

SLIDE 9

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Strong Production (RPC) : 0-lepton + ≥2-6 jets

ATLAS-CONF-2013-047

◮ No significant excess is seen.

(incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000

events / 100 GeV 1 10

2

10

3

10

4

10

5

10

1

L dt = 20.3 fb

∫

= 8 TeV) s Data 2012 ( SM Total )=100

1

χ ∼ )=850,m( q ~ m( q ~ q ~ )=400

1

χ ∼ )=450,m( q ~ m( q ~ q ~ Multijet Z+jets W+jets & single top t t Diboson

Preliminary ATLAS SRA - 2 jets Al (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000 DATA / MC 0.5 1 1.5 2 2.5 (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000

events / 100 GeV 1 10

2

10

3

10

4

10

1

L dt = 20.3 fb

∫

= 8 TeV) s Data 2012 ( SM Total )=100

1

χ ∼ )=850,m( q ~ m( q ~ q ~ )=400

1

χ ∼ )=450,m( q ~ m( q ~ q ~ Multijet Z+jets W+jets & single top t t Diboson

Preliminary ATLAS SRA - 2 jets Am (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000 DATA / MC 0.5 1 1.5 2 2.5 (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000

events / 100 GeV 1 10

2

10

3

10

4

10

1

L dt = 20.3 fb

∫

= 8 TeV) s Data 2012 ( SM Total )=525

1

χ ∼ )=1425,m( q ~ × )=1.04 m( g ~ m( g ~ q ~ )=37

1

χ ∼ )=1612,m( q ~ × )=1.04 m( g ~ m( g ~ q ~ Multijet Z+jets W+jets & single top t t Diboson

Preliminary ATLAS SRB - 3 jets Bm (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000 DATA / MC 0.5 1 1.5 2 2.5 (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000

events / 100 GeV 1 10

2

10

3

10

1

L dt = 20.3 fb

∫

= 8 TeV) s Data 2012 ( SM Total )=525

1

χ ∼ )=1425,m( q ~ × )=1.04 m( g ~ m( g ~ q ~ )=37

1

χ ∼ )=1612,m( q ~ × )=1.04 m( g ~ m( g ~ q ~ Multijet Z+jets W+jets & single top t t Diboson

Preliminary ATLAS SRB - 3 jets Bt (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000 DATA / MC 0.5 1 1.5 2 2.5 (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000

events / 100 GeV 1 10

2

10

3

10

1

L dt = 20.3 fb

∫

= 8 TeV) s Data 2012 ( SM Total =700

1/2

=1000,m CMSSM m )=550

1

χ ∼ )=700,m( g ~ m( g ~ g ~ Multijet Z+jets W+jets & single top t t Diboson

Preliminary ATLAS SRC - 4 jets Cm Ct (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000 DATA / MC 0.5 1 1.5 2 2.5 (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000

events / 100 GeV 1 10

2

10

3

10

1

L dt = 20.3 fb

∫

= 8 TeV) s Data 2012 ( SM Total )=337

1

χ ∼ )=1162,m( g ~ m( g ~ g ~ )=50

1

χ ∼ )=1250,m( g ~ m( g ~ g ~ Multijet Z+jets W+jets & single top t t Diboson

Preliminary ATLAS SRD - 5 jets Dt (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000 DATA / MC 0.5 1 1.5 2 2.5 (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000 4500

events / 150 GeV 1 10

2

10

1

L dt = 20.3 fb

∫

= 8 TeV) s Data 2012 ( SM Total )=505

1

χ ∼ )=785,m(

± 1

χ ∼ )=1065,m( g ~ m( g ~ g ~ )=465

1

χ ∼ )=865,m(

± 1

χ ∼ )=1265,m( g ~ m( g ~ g ~ Multijet Z+jets W+jets & single top t t Diboson

Preliminary ATLAS SRE - 6 jets El (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000 4500 DATA / MC 0.5 1 1.5 2 2.5 (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000 4500

events / 150 GeV 1 10

2

10

1

L dt = 20.3 fb

∫

= 8 TeV) s Data 2012 ( SM Total )=505

1

χ ∼ )=785,m(

± 1

χ ∼ )=1065,m( g ~ m( g ~ g ~ )=465

1

χ ∼ )=865,m(

± 1

χ ∼ )=1265,m( g ~ m( g ~ g ~ Multijet Z+jets W+jets & single top t t Diboson

Preliminary ATLAS SRE - 6 jets Em (incl.) [GeV]

eff

m 500 1000 1500 2000 2500 3000 3500 4000 4500 DATA / MC 0.5 1 1.5 2 2.5

9 / 37

SLIDE 10

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Strong Production (RPC) : 0-lepton + ≥2-6 jets

ATLAS-CONF-2013-047

◮ For direct decays present planes of m˜

g vs m ˜ χ0

1 and m˜

q vs m ˜ χ0

1 but also

m˜

g vs m˜ q for a variety of LSP masses.

◮ For decays through charginos vary LSP in one plane or splitting in other.

gluino mass [GeV] 800 1000 1200 1400 1600 1800 2000 2200 2400 squark mass [GeV] 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800

Squark-gluino-neutralino model =8 TeV s ,

1

L dt = 20.3 fb

∫

ATLAS Preliminary

0-lepton combined

)

theory SUSY

σ 1 ± ) = 0 GeV Observed limit (

1

χ ∼ m( )

exp

σ 1 ± ) = 0 GeV Expected limit (

1

χ ∼ m( ) = 395 GeV Observed limit

1

χ ∼ m( ) = 395 GeV Expected limit

1

χ ∼ m( ) = 695 GeV Observed limit

1

χ ∼ m( ) = 695 GeV Expected limit

1

χ ∼ m( ) = 0 GeV Observed

1

χ ∼ ) m(

1

7TeV (4.7fb

[GeV]

g ~

m 200 400 600 800 1000 1200 1400 [GeV]

1

χ ∼

m 200 400 600 800 1000 1200 1400

1

χ ∼ q q → g ~ production; g ~ g ~ =8 TeV s ,

1

L dt = 20.3 fb

∫

0-lepton combined

Preliminary ATLAS

)

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit ( , 7 TeV)

1

Observed limit (4.7 fb , 7 TeV)

1

Expected limit (4.7 fb

[GeV]

q ~

m 200 300 400 500 600 700 800 900 1000 1100 [GeV]

1

χ ∼

m 100 200 300 400 500 600 700

1

χ ∼ q → q ~ production; q ~ q ~ =8 TeV s ,

1

L dt = 20.3 fb

∫

0-lepton combined

Preliminary ATLAS

)

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit ( , 7 TeV)

1

Observed limit (4.7 fb , 7 TeV)

1

Expected limit (4.7 fb

gluino mass [GeV] 200 400 600 800 1000 1200 1400 1600 LSP mass [GeV] 200 400 600 800 1000 1200 1400 1600

1

χ ∼

1

χ ∼

±

W

±

W q q q q →

1 ±

χ ∼

1 ±

χ ∼ q q q q → g ~ g ~ Simplified model, ATLAS =8 TeV s ,

1

L dt = 20.3 fb

∫

Preliminary 0-lepton combined ) + m(LSP))/2 g ~ )= (m(

±

χ ∼ m( , 7 TeV)

1

Observed limit (4.7 fb )

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit ( L S P g ~

gluino mass [GeV] 200 400 600 800 1000 1200 1400 1600 ,LSP) g ~ m( ∆ ,LSP)/

±

χ m( ∆ x= 0.2 0.4 0.6 0.8 1 1.2 1.4

1

χ ∼

1

χ ∼

±

W

±

W q q q q →

1 ±

χ ∼

1 ±

χ ∼ q q q q → g ~ g ~ Simplified model, ATLAS =8 TeV s ,

1

L dt = 20.3 fb

∫

Preliminary 0-lepton combined m(LSP)=60[GeV]

, 7 TeV)

1

Observed limit (4.7 fb )

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit (

10 / 37

SLIDE 11

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Strong Production (RPC) : 0-lepton + ≥7-10 jets

arXiv:1308.1841

◮ Softer cuts on E miss

T

related variables + higher jet multiplicity.

◮ Multi-jet background from data-driven method.

2 4 6 8 10 12 14 16 1/2

Events / 4 GeV

1

10 1 10

2

10

3

10

4

10

5

10

6

10

7

10

8

10

1

L dt = 20.3 fb

∫

= 8 TeV s No b-jets > 50 GeV

T

8 jets p ATLAS

Data Total background Multi-jets ql,ll → t t Single top +W,Z t t + b-jets ν l → W + light jets ν l → W , ll + jets ν ν → Z ]:[900,150] [GeV]

1

χ ∼ , g ~ [

]

1/2

[GeV

T

H /

miss T

E 2 4 6 8 10 12 14 16

Data / Prediction 0.5 1 1.5 2

2 4 6 8 10 12 14 16 1/2

Events / 4 GeV

1

10 1 10

2

10

3

10

4

10

5

10

6

10

7

10

8

10

1

L dt = 20.3 fb

∫

= 8 TeV s 2 b-jets ≥ > 50 GeV

T

8 jets p ATLAS

Data Total background Multi-jets ql,ll → t t Single top +W,Z t t + b-jets ν l → W + light jets ν l → W , ll + jets ν ν → Z ]:[900,150] [GeV]

1

χ ∼ , g ~ [

]

1/2

[GeV

T

H /

miss T

E 2 4 6 8 10 12 14 16

Data / Prediction 0.5 1 1.5 2

2 4 6 8 10 12 14 16 1/2

Events / 4 GeV

2

10

1

10 1 10

2

10

3

10

4

10

5

10

1

L dt = 20.3 fb

∫

= 8 TeV s > 50 GeV

T

10 jets p ≥ ATLAS

Data Total background Multi-jets ql,ll → t t Single top +W,Z t t + b-jets ν l → W + light jets ν l → W , ll + jets ν ν → Z ]:[900,150] [GeV]

1

χ ∼ , g ~ [

]

1/2

[GeV

T

H /

miss T

E 2 4 6 8 10 12 14 16

Data / Prediction 0.5 1 1.5 2

11 / 37

SLIDE 12

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Strong Production (RPC) : 0-lepton + ≥7-10 jets

arXiv:1308.1841

◮ Due to binning in b-jets set limits in models with ˜

g → t¯ t ˜ χ0

1, and without

b-jets including an even longer decay chain.

) [GeV] g ~ m( 600 700 800 900 1000 1100 1200 1300 ) [GeV]

1

χ ∼ m( 100 200 300 400 500 600 700 800 900

) g ~ )>>m( t ~ ; m(

1

χ ∼ t t → g ~ , g ~

g

~

1

L dt = 20.3 fb

∫

Multijet Combined

ATLAS

)

exp

σ 1 ± Expected limit ( )

theory SUSY

σ 1 ± Observed limit ( )

1

χ ∼ m ( t ) + m ( × ) < 2 g ~ m (

) [GeV] g ~ m( 400 500 600 700 800 900 1000 1100 1200 Fractional mass splitting, x 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

)=60 GeV

1

χ ∼ ; m(

1

χ ∼ qqW → g ~ , g ~

g

~

1

L dt = 20.3 fb

∫

Multijet Combined

ATLAS

)

exp

σ 1 ± Expected limit ( )

theory SUSY

σ 1 ± Observed limit ( )

1

χ ∼ )-m( g ~ m( )

1

χ ∼ )-m(

± 1

χ ∼ m( x = ) [GeV] g ~ m( 500 600 700 800 900 1000 1100 1200 1300 1400 ) [GeV]

1

χ ∼ m( 100 200 300 400 500 600 700 800 900

;

1

χ ∼ qqWZ → g ~ , g ~

g

~ )]/2

1

χ ∼ )+m(

± 1

χ ∼ )=[m(

2

χ ∼ )]/2, m(

1

χ ∼ )+m( g ~ )=[m(

± 1

χ ∼ m(

1

L dt = 20.3 fb

∫

Multijet Combined

ATLAS

)

exp

σ 1 ± Expected limit ( )

theory SUSY

σ 1 ± Observed limit ( )

1

χ ∼ )<m( g ~ m(

12 / 37

SLIDE 13

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Strong Production (RPC) : 1-2 leptons + ≥3-6 jets

ATLAS-CONF-2013-062

◮ Search requiring an isolated electron or muon. ◮ Split into several categories based on the lepton pT. ◮ Multi-bin fit in meff or E miss

T

used for the final result.

13 / 37

SLIDE 14

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Strong Production (RPC) : 1-2 leptons + ≥3-6 jets

ATLAS-CONF-2013-062

◮ Interpretation in many different decay chains. ◮ Clear complementarity between hard and soft lepton regions. ◮ The soft lepton signal regions, with leptons with pT < 25 GeV, cover the

more compressed scenarios close to the diagonal on the plot.

◮ The hard lepton analysis loses sensitivity in these areas as the phase space

for the decay products of the pair produced SUSY particles is reduced.

◮ Also similar sensitivity to 0-lepton channels in the same models. ◮ Many further interpretations provided to those shown here.

[GeV]

g ~

m 400 600 800 1000 1200 1400 [GeV]

1

χ ∼

m 100 200 300 400 500 600 700 800 900 1000

, x=1/2

1

χ ∼

1

χ ∼ qqqqWW → g ~

g

~ )

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit ( =8 TeV s ,

1

L dt = 20.3 fb

∫

miss T

1-lepton + jets + E

1

χ ∼

< m

g ~

m PRD 86 (2012) 092002 Observed limit (hard lepton) Expected limit (hard lepton) Observed limit (soft lepton) Expected limit (soft lepton) All limits at 95% CL

ATLAS Preliminary

0.04 0.04 0.05 0.42 0.03 0.04 0.25 0.03 0.03 0.05 0.10 0.08 0.03 0.06 0.12 0.02 0.03 0.01 0.02 0.01 0.02 0.02 0.03 0.01 0.02 0.02 0.02 0.01 0.01 0.02 0.02 0.01 0.01 0.02 0.03 0.01 0.02 25 72 345 7 129 17 13 15 247 16 3 23 3 21 20 4 3 4 3 2 1 2 3 2 0.77 0.36 6 7 0.21 0.72 0.52 2 2 0.12 0.30 0.46 2 0.69 0.98 2 1 0.14 0.32 2 3 0.11 0.29 1 0.07 0.12 0.33 1 50.51 0.06 0.10 0.28 0.98 2 0.10 0.36 1 0.43 0.05 0.08 0.19 0.45 1 0.05 0.05 0.11 0.32 2 20.43 0.05 0.05 0.07 0.25 0.61 2 0.03 0.04 0.34 2 0.04 0.04 0.07

Numbers give 95% CL excluded model cross sections [pb]

[GeV]

g ~

m 400 600 800 1000 1200 1400 )

1

χ ∼

m

g ~

) / ( m

1

χ ∼

m

1 ±

χ ∼

X = ( m 0.2 0.4 0.6 0.8 1 1.2 1.4

= 60 GeV

1

χ ∼

, m

1

χ ∼

1

χ ∼ qqqqWW → g ~

g

~ )

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit ( =8 TeV s ,

1

L dt = 20.3 fb

∫

miss T

hard 1-lepton + jets + E PRD 86 (2012) 092002 All limits at 95% CL

ATLAS Preliminary

0.21 0.14 0.12 0.09 0.08 2 0.09 0.15 0.21 0.41 0.50 0.50 0.37 0.10 0.08 0.08 1 0.08 0.09 0.14 0.40 0.21 0.41 0.33 0.17 0.12 0.07 1 0.07 0.11 0.39 0.16 0.44 0.55 0.32 0.19 0.12 0.09 0.08 0.07 0.80 0.07 0.07 0.08 0.09 0.34 0.11 0.28 0.47 0.67 0.29 0.17 0.13 0.11 0.88 0.08 0.07 206 137 235 28 40 293 41 19 4 3 4 4 59 11 4 2 0.89 0.77 0.95 0.92 15 4 3 0.98 0.47 0.55 0.70 0.62 12 6 2 1 0.41 0.26 0.21 0.26 0.25 0.45 5 1 0.92 0.31 0.24 0.14 0.13 0.16 0.22 0.44 0.73 0.25 0.16 0.11 0.10 2 0.14 0.20 0.39

Numbers give 95% CL excluded model cross sections [pb]

[GeV]

g ~

m 400 600 800 1000 1200 1400 [GeV]

1

χ ∼

m 100 200 300 400 500 600 700 800 900 1000

1

χ ∼

1

χ ∼ qqqqWZWZ →

± 1

χ ∼

± 1

χ ∼ qqqq → g ~ g ~ decays via WWZZ: g ~

g

~ )

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit ( =8 TeV s ,

1

L dt = 20.3 fb

∫

miss T

hard 1-lepton + jets + E

1

χ ∼

< m

g ~

m PRD 86 (2012) 092002 All limits at 95% CL

ATLAS Preliminary

0.04 0.05 0.17 0.04 0.10 0.30 0.04 0.05 0.48 0.04 0.08 0.03 0.03 0.04 0.07 0.18 0.02 0.03 0.04 0.02 0.03 0.04 0.02 0.02 0.04 0.02 0.02 0.02 0.02 0.02 0.02 0.01 0.02 0.02 0.02 0.02 0.02 177 53 2 81 1 14 0.69 0.69 166 0.34 4 0.40 0.69 24 0.10 0.14 1 45 0.06 0.14 0.50 0.06 0.10 0.41 1 0.04 0.06 0.06 0.06 0.32 3

Numbers give 95% CL excluded model cross sections [pb]

14 / 37

SLIDE 15

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Strong Production (RPC) : 2 SS leptons + ≥0-3 b-jets

ATLAS-CONF-2013-007

◮ A selection of same-sign di-leptons results in very low Standard Model

backgrounds.

◮ Backgrounds result from rare processes (eg. WZ, t¯

t+V) and also from when we measure the charge wrong (charge-flip) or when one of the leptons is non-prompt (eg. from a b-hadron decay).

◮ Due to low background rates an ideal channel to search in difficult areas

f parameter space.

15 / 37

SLIDE 16

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Strong Production (RPC) : 2 SS leptons + ≥0-3 b-jets

ATLAS-CONF-2013-007

◮ Limits set using a binned fit across many signal regions. ◮ Left hand limit shows the gain from combining different regions. ◮ Many models are used for interpretation including an RPV scenario where

there is still sensitivity.

[GeV]

g ~

m

500 600 700 800 900 1000 1100 1200 1300

[GeV]

1

χ ∼

m

200 400 600 800 1000 1200

forbidden

1

χ ∼ t t → g ~

) g ~ ) >> m( t ~ , m(

1

χ ∼ t t → g ~ production, g ~

g

~ 2 same-charge leptons + jets =8 TeV s ,

1

L dt = 20.7 fb

∫

40 35 38 36 39 40 35 38 32 38 45 44 33 37 36 40 42 54 31 30 30 31 38 45 42 28 26 29 28 33 35 40 49 25 29 26 27 31 34 36 42 50 25 23 24 26 27 30 32 40 44 48 34 20 21 23 25 29 29 35 37 36 19 18 20 19 21 23 26 25 31 39 41 48 17 17 18 17 21 25 24 24 30 32 34 42 50 16 15 16 16 19 20 21 22 26 27 33 37 45 50 15 14 14 16 16 18 33 32 29 30 28 29 38 39 48 14 14 13 13 14 13 16 18 32 21 24 30 32 35 46 53 12 12 12 15 13 13 15 14 18 20 23 24 27 32 36 46 45 12 12 12 12 13 13 14 14 17 18 20 23 25 28 32 47 42 61 12 13 12 11 12 12 13 14 14 13 18 19 23 24 28 34 38 44 56

Numbers give 95% CL excluded model cross sections [fb] )

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit ( SR1b only SR3b only

ATLAS Preliminary

All limits at 95% CL

[GeV]

g ~

m

500 600 700 800 900 1000 1100 1200 1300

[GeV]

1

χ ∼

m

200 400 600 800 1000 1200

forbidden

1

χ ∼ t t → g ~

) g ~ ) >> m( t ~ , m(

1

χ ∼ t t → g ~ production, g ~

g

~ 2 same-charge leptons + jets =8 TeV s ,

1

L dt = 20.7 fb

∫

)

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit ( =8TeV s ,

1

3 b-jets, 12.8fb ≥ 0-leptons, =8TeV s ,

1

4 jets, 5.8fb ≥ 2-SameSign-leptons, =8TeV s ,

1

4 jets, 13.0fb ≥ 3-leptons,

ATLAS Preliminary

All limits at 95% CL

[GeV]

g ~

m

600 650 700 750 800 850 900 950 1000

[GeV]

t ~

m

450 500 550 600 650 700 750 800 850 900 950 bs → (RPV) t ~ t, t ~ → g ~ production, t ~

t

~ and g ~

g

~ 2 same-charge leptons + jets =8 TeV s ,

1

L dt = 20.7 fb

∫

65 58 55 41 123 123 381

Numbers give 95% CL excluded model cross sections [fb] )

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit (

ATLAS Preliminary

All limits at 95% CL

16 / 37

SLIDE 17

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Strong Production (RPC) : 0-1 leptons + ≥3 b-jets

ATLAS-CONF-2013-061

◮ Selections requiring ≥3 b-tagged jets also benefit from low standard

model backgrounds.

◮ Backgrounds with fake b-jets (from light, charm or tau jets) are

determined using a data-driven method.

◮ Selections both vetoing and requiring an electron or muon are covered.

17 / 37

SLIDE 18

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Strong Production (RPC) : 0-1 leptons + ≥3 b-jets

ATLAS-CONF-2013-061

◮ Combined limits from the 0 and 1 lepton analyses provide powerful

exclusion in gluino mediated stop production.

◮ These form the most powerful limits on the “natural” ˜

g → b¯ b ˜ χ0

1 and

˜ g → t¯ t ˜ χ0

1 .

◮ Limits extend to beyond 1.3 TeV in gluino mass for light LSP.

[GeV]

g ~

m 400 600 800 1000 1200 1400 [GeV]

1

χ ∼

m 200 400 600 800 1000 1200 1400 f

r

b i d d e n

1

χ ∼ + b b → g ~ ) g ~ ) >> m( q ~ , m(

1

χ ∼ + b b → g ~ production, g ~ g ~ =8 TeV s ,

1

= 20.1 fb

int

L 0 lepton + 3 b-jets channel All limits at 95% CL

ATLAS

exp

σ 1 ± Expected limit

Theory SUSY

σ 1 ± Observed limit

1

0-l + 3 b-jets, 12.8 fb

Preliminary

[GeV]

g ~

m 600 800 1000 1200 1400 [GeV]

1

χ ∼

m 200 400 600 800 1000 f

r

b i d d e n

1

χ ∼ + t t → g ~ ) g ~ ) >> m( q ~ , m(

1

χ ∼ + t t → g ~ production, g ~ g ~ =8 TeV s ,

1

= 20.1 fb

int

L 0 and 1 lepton + 3 b-jets channels All limits at 95% CL

ATLAS

exp

σ 1 ± Expected limit

Theory SUSY

σ 1 ± Observed limit

1

0-l + 3 b-jets, 12.8 fb

Preliminary

[GeV]

g ~

m 400 600 800 1000 1200 1400 [GeV]

1

χ ∼

m 100 200 300 400 500 600 700 800 900 1000 1100 f

r

b i d d e n

± 1

χ ∼ + t b → g ~ ) g ~ ) >> m( q ~ , m(

± 1

χ ∼ + t b → g ~ production, g ~ g ~ =8 TeV s ,

1

= 20.1 fb

int

L 0 and 1 lepton + 3 b-jets channels ) = 2 GeV

1

χ ∼ ) - m(

± 1

χ ∼ m(

1

χ ∼ ff’ + →

± 1

χ ∼ All limits at 95% CL

ATLAS

exp

σ 1 ± Expected limit

Theory SUSY

σ 1 ± Observed limit , 7 TeV

1

0-l + 3 b-jets, 4.7 fb

Preliminary

18 / 37

SLIDE 19

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Stop and Sbottom Searches (RPC)

◮ With the full Run 1 dataset good sensitivity to direct stop and sbottom

pair production is possible.

◮ However, with their lower cross-section and the large t¯

t background which is similar to the signal dedicated analyses were set up to target various different decay modes.

10

3

10

2

10

1

1 10 200 400 600 800 1000 1200 1400 1600

ν ˜eν ˜e* l ˜el ˜e* t ˜1t ˜1* q ˜q ˜ q ˜q ˜* g ˜g ˜ q ˜g ˜ χ ˜ 2

g

˜ χ ˜ 2

χ

˜ 1

+

maverage [GeV] σtot[pb]: pp → SUSY √S = 8 TeV

19 / 37

SLIDE 20

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Stop and Sbottom Searches (RPC) : 2 b-jets + E miss

T

arXiv:1308.2631

◮ Nominally targeting ˜

b → b + ˜ χ0

1.

◮ Makes use of kinematics of the signal/background with mCT and mbb. ◮ Exploit ISR boost of the system in a second signal region for small mass

splitting.

Events / 25 GeV 20 40 60 80 100 120 ATLAS SRA

1

= 8 TeV, 20.1 fb s Data SM total top-quark production W production Z production Others )=1 GeV

1

χ ∼ )=500 GeV, m(

1

b ~ m( )=100 GeV

1

χ ∼ )=500 GeV , m(

1

t ~ m( )=105 GeV

± 1

χ ∼ m(

[GeV]

CT

m 50 100 150 200 250 300 350 400 450 500 Data / SM 1 2 Events / 40 GeV 10 20 30 40 50 60 70 ATLAS SRA

1

= 8 TeV, 20.1 fb s Data SM total top-quark production W production Z production Others )=1 GeV

1

χ ∼ )=500 GeV , m(

1

b ~ m( )=100 GeV

1

χ ∼ )=500 GeV , m(

1

t ~ m( )=105 GeV

± 1

χ ∼ m(

[GeV]

bb

m 100 200 300 400 500 600 Data / SM 1 2

20 / 37

SLIDE 21

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Stop and Sbottom Searches (RPC) : 2 b-jets + E miss

T

arXiv:1308.2631

◮ As well as giving good sensitivity to sbottom production with direct

decays to the LSP, good sensitivity is found for stop production when the decay is through a chargino which is nearly degerate with the LSP such that the chargino decay products are very soft. ˜ t → b + ˜ χ±

1

˜ χ±

1 → f + f

′ + ˜

χ0

1

[GeV]

1

b ~

m 100 200 300 400 500 600 700 800 [GeV]

1

χ ∼

m 100 200 300 400 500 600

forbidden

1

χ ∼ b →

1

b ~

1

CDF 2.65 fb

1

D0 5.2 fb =7 TeV s ,

1

ATLAS 2.05 fb

1

χ ∼ b →

1

b ~ Sbottom pair production, =8 TeV s ,

1

Ldt = 20.1 fb

∫

ATLAS

)

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit ( All limits at 95% CL

[GeV]

+ 1

χ ∼

m 100 120 140 160 180 200 220 240 260 280 [GeV]

1

χ ∼

m 50 100 150 200 250 300 350

1

χ ∼

<m

1 +

χ ∼

m

) = 300 GeV

1

t ~ , m(

1 +

χ ∼ b →

1

t ~ Stop pair production, =8 TeV s ,

1

Ldt = 20.1 fb

∫

ATLAS

)

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit ( All limits at 95% CL

[GeV]

1

t ~

m 200 300 400 500 600 700 [GeV]

1

χ ∼

m 100 150 200 250 300 350 400 450 500 550 600

forbidden

1 +

χ ∼ b →

1

t ~

) = 5 GeV

1

χ ∼ )-m(

1 +

χ ∼ , m(

1 +

χ ∼ b →

1

t ~ Stop pair production, =8 TeV s ,

1

Ldt = 20.1 fb

∫

ATLAS

)

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit ( All limits at 95% CL

21 / 37

SLIDE 22

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Stop and Sbottom Searches (RPC) : 0-lepton Stop

ATLAS-CONF-2013-024

◮ Targeting the model ˜

t → t + ˜ χ0

1.

◮ Uses kinematic variables to reject the t¯

t background - fully reconstruct both tops to reject semi-leptonic t¯ t background.

◮ These variables are found to be well described in top dominated CRs.

100 200 300 400 500 600

Events / 50 GeV

20 40 60 80 100 120 140 160 >200 GeV

miss T

E 1-lepton, CRTop Data 2012 SM Total t t SingleTop +V t t W Z Diboson )=(400,1) GeV

1

χ ∼ ,

1

t ~ ( )=(600,1) GeV

1

χ ∼ ,

1

t ~ ( = 8 TeV s ,

1

L dt = 20.5 fb

∫

ATLAS Preliminary

[GeV]

jjj

m

100 200 300 400 500 600

Data / SM

0.5 1 1.5 2 >

22 / 37

SLIDE 23

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Stop and Sbottom Searches (RPC) : 1-lepton Stop

ATLAS-CONF-2013-037

◮ Different signal regions targeting the different possible decays. ◮ For ˜

t → t + ˜ χ0

1 a binned fit is performed across the mT and E miss T

plane.

100 125 150 60 90 120 140 60 90 Emiss

T

(GeV) mT (GeV) Lint = 20.7 fb−1 √s = 8 TeV ATLAS Preliminary

≥1 b-jet b-jet veto Total Fitted Background Data Signal (mstop, mLSP) = (350, 150)

1289 ± 85 825 ± 56 1441 ± 103 3122 ± 116 1962 ± 60 2591 ± 104 1535 ± 260 760 ± 120 695 ± 151 290 ± 60 145 ± 23 101 ± 26 250 ± 57 174 ± 28 262 ± 34 1289 825 1441 3122 1962 2591 1521 721 663 268 119 113 253 165 235 1 1 4 14 10 19 16 13 22 8 8 15 16 18 41

Events 1 10

2

10

3

10

4

10

5

10

6

10

7

10 Data 2012 Standard Model (SM) t t W+Jets +V, single top, multijets t t Z+Jets, VV

= 150 [GeV]

χ

= 350, m

t ~

m

1

L dt = 20.7 fb

∫

= 8 TeV, s channel µ e+ Preliminary ATLAS tN1 shape: < 125 GeV

miss T

100 GeV < E [GeV]

T

m W-CR 60-90 90-120 120-140 >140 Data/SM 0.5 1 1.5 Events 1 10

2

10

3

10

4

10

5

10

6

10

7

10 Data 2012 Standard Model (SM) t t W+Jets +V, single top, multijets t t Z+Jets, VV

= 150 [GeV]

χ

= 350, m

t ~

m

1

L dt = 20.7 fb

∫

= 8 TeV, s channel µ e+ Preliminary ATLAS tN1 shape: < 150 GeV

miss T

125 GeV < E [GeV]

T

m W-CR 60-90 90-120 120-140 >140 Data/SM 0.5 1 1.5 Events 1 10

2

10

3

10

4

10

5

10

6

10

7

10 Data 2012 Standard Model (SM) t t W+Jets +V, single top, multijets t t Z+Jets, VV

= 150 [GeV]

χ

= 350, m

t ~

m

1

L dt = 20.7 fb

∫

= 8 TeV, s channel µ e+ Preliminary ATLAS tN1 shape: > 150 GeV

miss T

E [GeV]

T

m W-CR 60-90 90-120 120-140 >140 Data/SM 0.5 1 1.5

23 / 37

SLIDE 24

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Stop and Sbottom Searches (RPC) : 2-lepton Stop

ATLAS-CONF-2013-048

◮ Requiring two leptons has a large branching ratio hit. ◮ However, this is still sets the best limits for ˜

t → Wb ˜ χ0

1.

◮ Utilises the kinematic variable mT2 to distinguish signal and background.

mT2(pl1

T, pl2 T, E miss T

) = minq1+q2=E miss

T

max(mT(pl1

T, q1), mT(pl2 T, q2)

◮ A separate search targets heavier stop particles. ATLAS-CONF-2013-065

20 40 60 80 100 120 140 160 180 200 Events / bin 1 10

2

10

3

10

4

10

5

10

6

10

1

L dt ~ 20.3 fb

∫

ATLAS Preliminary

inclusive

(a) same flavour

Data 2012 SM Background Z+jets t t WW ZZ+WZ Single top Fake leptons + V t t )=(150,120,1) GeV

1

χ ,

±

χ m(stop, )=(400,250,1) GeV

1

χ ,

±

χ m(stop,

[GeV]

T2

m 20 40 60 80 100 120 140 160 180 200 Data/MC 0.5 1 1.5 2

≥

20 40 60 80 100 120 140 160 180 200 Events / bin 1 10

2

10

3

10

4

10

5

10

1

L dt ~ 20.3 fb

∫

ATLAS Preliminary

inclusive

(b) different flavour

Data 2012 SM Background Z+jets t t WW ZZ+WZ Single top Fake leptons + V t t )=(150,120,1) GeV

1

χ ,

±

χ m(stop, )=(400,250,1) GeV

1

χ ,

±

χ m(stop,

[GeV]

T2

m 20 40 60 80 100 120 140 160 180 200 Data/MC 0.5 1 1.5

≥ 24 / 37

SLIDE 25

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Stop and Sbottom Searches (RPC) : Light Stop

ATLAS-CONF-2013-068

◮ When the mass difference between the LSP and the stop is small then the

stop can decay ˜ t → c ˜ χ0

1.

◮ Searches for these compressed scenarios rely on ISR and are either

Mono-jet-like or the other jets are resolved and are c-tagged.

400 600 800 1000 1200 1400

[ Events / GeV ]

T miss

dN/dE

3

10

2

10

1

10 1 10

2

10

3

10

4

10

Data 2012 Standard Model ) + jets ν ν → Z ( ) + jets ν l → W ( ll ) + jets → Z ( (+X) + single top t t dibosons )= (200,195) GeV χ ∼ , t ~ m( )= (200,125) GeV χ ∼ , t ~ m(

= 8 TeV s ,

1

Ldt=20.3 fb

∫

ATLAS Preliminary 400 600 800 1000 1200 1400

[ Events / GeV ]

T miss

dN/dE

3

10

2

10

1

10 1 10

2

10

3

10

4

10 [GeV]

T miss

E 400 600 800 1000 1200 1400 Data / SM 1 2 Events / 50 GeV

1

10 1 10

2

10

3

10

4

10

Data 2012 Standard Model ) +jets ν l → W ( (+X) + single top t t ) +jets ν ν → Z ( ll ) +jets → Z ( dibosons multijets ) = (200,195) GeV

1

χ ∼ , t ~ m( ) = (200,125) GeV

1

χ ∼ , t ~ m(

ATLAS Preliminary

∫

= 8 TeV s ,

1

Ldt = 20.3 fb [GeV]

miss T

E 200 300 400 500 600 700 800 900 1000 Data / SM 1 2

25 / 37

SLIDE 26

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Stop and Sbottom Searches (RPC) : Limits

[GeV]

1

t ~

m

200 300 400 500 600 700

[GeV]

1

χ ∼

m

50 100 150 200 250 300 350 400

1

χ ∼ t →

1

t ~ 0L,

1

χ ∼ t →

1

t ~ 1L,

1

χ ∼ t →

1

t ~ 2L,

1

χ ∼ W b →

1

t ~ 2L,

1

χ ∼ c →

1

t ~ 0L mono-jet/c-tag,

1

χ ∼

+m

t

< m

1

t ~

m

1

χ ∼

+ m

W

+ m

b

< m

1

t ~

m

1

χ ∼

+ m

c

< m

1

t ~

m 1

χ ∼ c →

1

t ~ /

1

χ ∼ W b →

1

t ~ /

1

χ ∼ t →

1

t ~ production,

1

t ~

1

t ~ Status: SUSY 2013

ATLAS Preliminary

1

= 4.7 fb

int

L

1

21 fb ≈

int

L

1

χ ∼ W b

1

= 20 fb

int

L

1

χ ∼ c

1

= 20.3 fb

int

L

Observed limits Expected limits

All limits at 95% CL [1203.4171]

1

CDF 2.6 fb

=8 TeV s

1

= 20 - 21 fb

int

L =7 TeV s

1

= 4.7 fb

int

L

0L CONF-2013-024 1L CONF-2013-037 2L CONF-2013-065 2L CONF-2013-048 0L mono-jet/c-tag CONF-2013-068 0L [1208.1447] 1L [1208.2590] 2L [1209.4186]

26 / 37

SLIDE 27

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Stop and Sbottom Searches (RPC) : Limits

◮ There also also limits set in models where the stop decays through a

chargino under various different mass splitting scenarios.

200 300 400 500 600 50 100 150 200 250 300 350

( = 150 GeV)

1

χ ∼

< m

1 ±

χ ∼

m ( = 106 GeV)

1

χ ∼

< m

1 ±

χ ∼

m

[GeV]

1

t ~

m

200 300 400 500 600 50 100 150 200 250 300 350

1

G e V )

1

t ~

= m

1 ±

χ ∼

( m

1

χ ∼

< m

1 ±

χ ∼

m

[GeV]

1

t ~

m

200 300 400 500 600

[GeV]

1

χ ∼

m

50 100 150 200 250 300 350

)

1

χ ∼

m × = 2

1 ±

χ ∼

( m

1 ±

χ ∼

+m

b

< m

1

t ~

m < 103.5 GeV

1 ±

χ ∼

m 200 300 400 500 600

[GeV]

1

χ ∼

m

50 100 150 200 250 300 350

+5 GeV)

1

χ ∼

= m

1 ±

χ ∼

( m

1 ±

χ ∼

+m

b

< m

1

t ~

m < 103.5 GeV

1 ±

χ ∼

m

LEP Observed limits Expected limits

All limits at 95% CL + 5 GeV

1 χ ∼

= m

± 1 χ

m + 20 GeV

1 χ ∼

= m

± 1 χ

m = 150 GeV

± 1 χ

m = 106 GeV

± 1 χ

m

1

χ ∼

m × = 2

± 1

χ

m

1

χ ∼

m × = 2

± 1

χ

m

10 GeV

1

t ~

= m

± 1

χ

m

ATLAS Preliminary, =8 TeV, s

1

= 20-21 fb

int

L Status: SUSY 2013 ,

1

χ ∼

(*)

W →

1 ±

χ ∼ ,

1 ±

χ ∼ b →

1

t ~ production,

1

t ~

1

t ~

0-1L 1308.2631, ATLAS-CONF-2013-062 0-1L 1308.2631, ATLAS-CONF-2013-062 0-1-2L 1308.2631, CONF-2013-037, CONF-2013-048 =7 TeV] s

1

= 4.7 fb

int

1-2L 1208.4305, 1209.2102 [L 2L ATLAS-CONF-2013-048 1-2L CONF-2013-037, CONF-2013-048 =7 TeV] s

1

= 4.7 fb

int

1-2L 1209.2102 [L

[GeV]

1 +

χ ∼

m

100 120 140 160 180 200 220 240 260 280

[GeV]

1

χ ∼

m

50 100 150 200 250 300

1 +

χ ∼

> m

1

χ ∼

m Observed limits Expected limits All limits at 95% CL

ATLAS Preliminary

Status: SUSY 2013 = 300 GeV

1

t ~

, m

1

χ ∼

(*)

W →

1 +

χ ∼ ,

1 +

χ ∼ b →

1

t ~ production,

1

t ~

1

t ~

=8 TeV s

1

~ 20 fb

int

L

ATLAS-CONF-2013-065 1308.2631 LEP 2L, 0L,

27 / 37

SLIDE 28

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Electro-weak Production Searches (RPC)

◮ Production of electo-weak SUSY particles has a very low cross-section

but using 2 and 3 lepton channels, 2 τ channels and 1-lepton + 2 b-jets, sensitivity to this can be achieved.

◮ The following processes have been considered:

28 / 37

SLIDE 29

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Electro-weak Production Searches (RPC) : 2-lepton and 2-τ searches

ATLAS-CONF-2013-049, ATLAS-CONF-2013-028

◮ Both of these use mT2 to distinguish the signal from backgrounds where

the E miss

T

comes solely from W decays.

◮ In the 2-τ channel there is a significant fake τ background that is

estimated in a data-driven way.

◮ These searches also set limits on direct slepton production.

[GeV]

T2

m

20 40 60 80 100 120 140 160 180 200 Data / SM 0.5 1 1.5 2 Events / 10 GeV

1

10 1 10

2

10

3

10

4

10

5

10

6

10

Data 2012 WW + Wt t t Z+jets ZV Fake leptons Higgs

Bkg. Uncert.

) = (350,0) GeV

1

χ ∼ ,m

1 ±

χ ∼ (m >40 GeV

miss,rel T

nJets=0, Zveto, E µ e

=8 TeV s

1

L dt=20.3 fb

∫

ATLAS Preliminary

) [GeV] l ~ m( 100 150 200 250 300 350 ) [GeV]

1

χ ∼ m( 50 100 150 200 250

)

1

χ ∼ )= m(

±

l ~ m( ) theory SUSY σ 1 ± Observed limit ( ) exp σ ± Expected limit ( excluded R µ ∼ LEP

ATLAS Preliminary

=8 TeV s ,

1

L dt = 20.3 fb

∫

1

χ ∼

l

1

χ ∼

+

l →

R

l ~

+ R

l ~ )

theory SUSY

σ 1 ± Observed limit ( )

exp

σ ± Expected limit ( excluded

R

µ ∼ LEP All limits at 95% CL

[GeV]

miss T

E 50 100 150 200 250 300 Events / 10 GeV

2

10

1

10 1 10

2

10

3

10

4

10

5

10

6

10

= 8 TeV) s Data 2012 ( SM Total Multi-jet,W+jets Z+jets Diboson t t Single top SUSY Ref. Point 1 SUSY Ref. Point 2

ATLAS Preliminary

1

L dt ~ 20.7 fb

∫

nobjet

T2

OS m SR

[GeV]

T2

m 50 100 150 200 250 300 Data/SM 0.5 1 1.5 2

29 / 37

SLIDE 30

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Electro-weak Production Searches (RPC) : 3-lepton search

ATLAS-CONF-2013-035

◮ For a 3-lepton selection one of the primary backgrounds is WZ

production.

◮ The analysis splits events into regions where there is an opposite sign

same flavour lepton pair near the Z mass and when there isn’t.

◮ This is the reason for the interesting shape to the exclusion in the

simplified model.

[GeV]

1 ±

χ ∼ ,

2

χ ∼

m

100 150 200 250 300 350 400

[GeV]

1

χ ∼

m

50 100 150 200 250 300

1

χ ∼

< m

2

χ ∼

m

Z

= m

1

χ ∼

m

2

χ ∼

m

1

χ ∼

= 2m

2

χ ∼

m

2

χ ∼

= m

± 1

χ ∼

m

1

χ ∼

(*)

Z

1

χ ∼

(*)

W →

2

χ ∼

± 1

χ ∼

ATLAS Preliminary

=8 TeV s ,

1

L dt = 20.7 fb

∫

)

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit ( = 8 TeV s ,

1

ATLAS 13.0 fb All limits at 95% CL

30 / 37

SLIDE 31

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Electro-weak Production Searches (RPC) : WH decay

ATLAS-CONF-2013-093

◮ As a new boson has been discovered and its mass has been measured this

information can now be used in searches where it might show up.

◮ Sensitivity is found for chargino-neutralino production where they decay

via a W and a Higgs boson respectively.

◮ The invariant mass of the b-tagged jets is a key distinguishing variable

between the signal and the background.

[GeV]

bb

m

Events

2 4 6 8 10 12 14 16 18 20 = 8 TeV s Data SM Total t t single top W+jets Z+jets +W/Z t t WW/WZ/ZZ WH ZH = 130, 0 GeV

1

χ

, m

2

χ ,

1 ±

χ

m = 225, 0 GeV

1

χ

, m

2

χ ,

1 ±

χ

m

ATLAS Preliminary

1

L dt ~ 20.3 fb

∫

SRA

[GeV]

bb

m

50 100 150 200 250 300 350 400

Data/SM

0.5 1 1.5 2 2.5 [GeV]

bb

m

Events

2 4 6 8 10 12 14 16 18 20 = 8 TeV s Data SM Total t t single top W+jets Z+jets +W/Z t t WW/WZ/ZZ WH ZH = 130, 0 GeV

1

χ

, m

2

χ ,

1 ±

χ

m = 225, 0 GeV

1

χ

, m

2

χ ,

1 ±

χ

m

ATLAS Preliminary

1

L dt ~ 20.3 fb

∫

SRB

[GeV]

bb

m

50 100 150 200 250 300 350 400

Data/SM

0.5 1 1.5 2 2.5

31 / 37

SLIDE 32

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Electro-weak Production Searches (RPC)

) [GeV]

2

χ ∼

(=m

1 ±

χ ∼

m 100 200 300 400 500 600 [GeV]

1

χ ∼

m 50 100 150 200 250 300 350 400 450 500

Expected limits Observed limits

ATLAS-CONF-2013-035

, µ , 3e/ ν ∼ /

L

l ~ , via

2

χ ∼

± 1

χ ∼ → pp

ATLAS-CONF-2013-049

, µ , 2e/ ν ∼ /

L

l ~ , via

1

χ ∼

+ 1

χ ∼ → pp

ATLAS-CONF-2013-028

, τ , 2

τ

ν ∼ /

L

τ ∼ , via

2

χ ∼

± 1

χ ∼ → pp

ATLAS-CONF-2013-028

, τ , 2

τ

ν ∼ /

L

τ ∼ , via

1

χ ∼

+ 1

χ ∼ → pp

ATLAS-CONF-2013-035

, µ , via WZ, 3e/

2

χ ∼

± 1

χ ∼ → pp

ATLAS-CONF-2013-093

bb, µ , via Wh, e/

2

χ ∼

± 1

χ ∼ → pp

=8 TeV Status: SUSY 2013 s ,

1

= 20.3-20.7 fb

int

Preliminary L ATLAS

)

2

χ ∼

+ m

1

χ ∼

= 0.5(m

ν ∼ /

L

τ ∼ /

L

l ~

m

1

χ ∼

< m

2

χ ∼

m

Z

+ m

1

χ ∼

= m

2

χ ∼

m

h

+ m

1

χ ∼

= m

2

χ ∼

m

1

χ ∼

= 2 m

2

χ ∼

m

32 / 37

SLIDE 33

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

RPV Searches and Long lived particles

◮ Firstly, some of the RPC searches can be quite effective in RPV scenarios

(as seen in some of the interpretations and also in re-interpretation literature).

◮ There are also dedicated searches for RPV signatures:

◮ High jet multiplicity ATLAS-CONF-2013-091 ◮ ≥4 leptons ATLAS-CONF-2013-036

◮ SUSY particles can be long lived due to:

◮ Weak couplings (e.g. in RPV, gravitino) ◮ Very small mass splittings (e.g. AMSB) ◮ Very heavy mediator particles (e.g. split SUSY)

◮ We have searches looking for these signature too:

◮ Stopped gluinos and squark R-Hadrons arXiv:1310.6584 ◮ Disappearing tracks arXiv:1310.3675 ◮ Muon+displaced vertex ATLAS-CONF-2013-092 ◮ Long lived sleptons ATLAS-CONF-2013-058

33 / 37

SLIDE 34

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Others Searches

◮ I haven’t been able to cover all the searches that ATLAS has performed

in the quest for SUSY.

◮ Additional searches requiring hadronic taus, Z → ll and photons have

also been performed to cover these important signatures.

◮ Also the exotics group performs a wide

range of searches which are applicable to some SUSY scenarios. (link)

[TeV] Λ 40 50 60 70 80 90 100 β tan 10 20 30 40 50 60

=1

grav

>0, C µ =3,

5

=250 TeV, N

mess

GMSB: M

Theory excl.

(1000 GeV) g ~ (1200 GeV) g ~ (1400 GeV) g ~ (1600 GeV) g ~ (1800 GeV) g ~ (2000 GeV) g ~

Theory excl.

ATLASPreliminary

=8 TeV s ,

1

L dt = 20.7 fb

∫

) theory SUSY σ 1 ± Observed limit ( ) exp σ 1 ± Expected limit ( (different spectrum generator) Combined 7 TeV Exclusion ) 1 τ ∼ OPAL 95% CL (

[GeV]

1

χ ∼

m 200 400 600 800 1000 1200 [GeV]

q ~

m 700 800 900 1000 1100 1200 1300 1400 1500

ATLAS

∫

= 7 TeV s ,

1

L dt = 4.7 fb )

theory SUSY

σ 1 ± Observed limit ( )

exp

σ 1 ± Expected limit ( < 0.1mm τ =2, c β GGM: bino-like neutralino, tan

1

χ ∼

< m

q ~

m Mass scale [TeV]

1

10 1 10

2

10 Other Excit.

ferm. New quarks LQ V’ CI Extra dimensions Magnetic monopoles (DY prod.) : highly ionizing tracks Multi-charged particles (DY prod.) : highly ionizing tracks

jj

m Color octet scalar : dijet resonance,

ll

m ), µ µ ll)=1) : SS ee ( →

L ± ±

(DY prod., BR(H

L ± ±

H

Zl

m (type III seesaw) : Z-l resonance,

±

Heavy lepton N

Major. neutr. (LRSM, no mixing) : 2-lep + jets

WZ

m ll), ν Techni-hadrons (LSTC) : WZ resonance (l

µ µ ee/

m Techni-hadrons (LSTC) : dilepton,

γ l

m resonance, γ Excited leptons : l-

Wt

m Excited b quark : W-t resonance,

jj

m Excited quarks : dijet resonance,

jet γ

m

jet resonance,

γ Excited quarks :

q ν l

m Vector-like quark : CC, Ht+X → Vector-like quark : TT

,miss T

E SS dilepton + jets + → 4th generation : b’b’ WbWb → generation : t’t’

th

4 jj ν τ jj, τ τ =1) : kin. vars. in β Scalar LQ pair ( jj ν µ jj, µ µ =1) : kin. vars. in β Scalar LQ pair ( jj ν =1) : kin. vars. in eejj, e β Scalar LQ pair (

tb

m tb, LRSM) : → (

R

W’

tq

m =1) :

R

tq, g → W’ (

µ T,e/

m W’ (SSM) :

tt

m l+jets, → t Z’ (leptophobic topcolor) : t

τ τ

m Z’ (SSM) :

µ µ ee/

m Z’ (SSM) :

,miss T

E uutt CI : SS dilepton + jets +

ll

m , µ µ qqll CI : ee & )

jj

m ( χ qqqq contact interaction : )

jj

m (

χ

Quantum black hole : dijet, F

T

p Σ =3) : leptons + jets,

D

M /

TH

M ADD BH (

ch. part.

N =3) : SS dimuon,

D

M /

TH

M ADD BH (

tt

m l+jets, → t (BR=0.925) : t t t →

KK

RS g

lljj

m Bulk RS : ZZ resonance,

ν l ν ,l T

m RS1 : WW resonance,

ll

m RS1 : dilepton,

ll

m ED : dilepton,

2

/Z

1

S

,miss T

E UED : diphoton +

/ ll γ γ

m Large ED (ADD) : diphoton & dilepton,

,miss T

E Large ED (ADD) : monophoton +

,miss T

E Large ED (ADD) : monojet + mass

862 GeV , 7 TeV [1207.6411]

1

=2.0 fb L

mass (|q| = 4e) 490 GeV

, 7 TeV [1301.5272]

1

=4.4 fb L

Scalar resonance mass 1.86 TeV

, 7 TeV [1210.1718]

1

=4.8 fb L

) µ µ mass (limit at 398 GeV for

L ± ±

H 409 GeV

, 7 TeV [1210.5070]

1

=4.7 fb L

| = 0)

τ

| = 0.063, |V

µ

| = 0.055, |V

e

mass (|V

±

N

245 GeV , 8 TeV [ATLAS-CONF-2013-019]

1

=5.8 fb L

) = 2 TeV)

R

(W m N mass ( 1.5 TeV

, 7 TeV [1203.5420]

1

=2.1 fb L

))

T

ρ ( m ) = 1.1

T

(a m ,

W

m ) +

T

π ( m ) =

T

ρ ( m mass (

T

ρ 920 GeV

, 8 TeV [ATLAS-CONF-2013-015]

1

=13.0 fb L

)

W

) = M

T

π ( m ) -

T

ω /

T

ρ ( m mass (

T

ω /

T

ρ 850 GeV

, 7 TeV [1209.2535]

1

=5.0 fb L

= m(l*)) Λ l* mass ( 2.2 TeV

, 8 TeV [ATLAS-CONF-2012-146]

1

=13.0 fb L

b* mass (left-handed coupling) 870 GeV

, 7 TeV [1301.1583]

1

=4.7 fb L

q* mass 3.84 TeV

, 8 TeV [ATLAS-CONF-2012-148]

1

=13.0 fb L

q* mass 2.46 TeV

, 7 TeV [1112.3580]

1

=2.1 fb L

)

Q

/m ν =

qQ

κ VLQ mass (charge -1/3, coupling 1.12 TeV

, 7 TeV [ATLAS-CONF-2012-137]

1

=4.6 fb L

T mass (isospin doublet) 790 GeV

, 8 TeV [ATLAS-CONF-2013-018]

1

=14.3 fb L

b’ mass 720 GeV

, 8 TeV [ATLAS-CONF-2013-051]

1

=14.3 fb L

t’ mass 656 GeV

, 7 TeV [1210.5468]

1

=4.7 fb L

gen. LQ mass

rd

3 534 GeV

, 7 TeV [1303.0526]

1

=4.7 fb L

gen. LQ mass

nd

2 685 GeV

, 7 TeV [1203.3172]

1

=1.0 fb L

gen. LQ mass

st

1 660 GeV

, 7 TeV [1112.4828]

1

=1.0 fb L

W’ mass 1.84 TeV

, 8 TeV [ATLAS-CONF-2013-050]

1

=14.3 fb L

W’ mass 430 GeV

, 7 TeV [1209.6593]

1

=4.7 fb L

W’ mass 2.55 TeV

, 7 TeV [1209.4446]

1

=4.7 fb L

Z’ mass 1.8 TeV

, 8 TeV [ATLAS-CONF-2013-052]

1

=14.3 fb L

Z’ mass 1.4 TeV

, 7 TeV [1210.6604]

1

=4.7 fb L

Z’ mass 2.86 TeV

, 8 TeV [ATLAS-CONF-2013-017]

1

=20 fb L

(C=1) Λ 3.3 TeV

, 8 TeV [ATLAS-CONF-2013-051]

1

=14.3 fb L

(constructive int.) Λ 13.9 TeV

, 7 TeV [1211.1150]

1

=5.0 fb L

Λ 7.6 TeV

, 7 TeV [1210.1718]

1

=4.8 fb L

=6) δ (

D

M 4.11 TeV

, 7 TeV [1210.1718]

1

=4.7 fb L

=6) δ (

D

M 1.5 TeV

, 7 TeV [1204.4646]

1

=1.0 fb L

=6) δ (

D

M 1.25 TeV

, 7 TeV [1111.0080]

1

=1.3 fb L

mass

KK

g 2.07 TeV

, 7 TeV [1305.2756]

1

=4.7 fb L

= 1.0)

Pl

M / k Graviton mass ( 850 GeV

, 8 TeV [ATLAS-CONF-2012-150]

1

=7.2 fb L

= 0.1)

Pl

M / k Graviton mass ( 1.23 TeV

, 7 TeV [1208.2880]

1

=4.7 fb L

= 0.1)

Pl

M / k Graviton mass ( 2.47 TeV

, 8 TeV [ATLAS-CONF-2013-017]

1

=20 fb L

1

~ R

KK

M 4.71 TeV

, 7 TeV [1209.2535]

1

=5.0 fb L

1
Compact. scale R

1.40 TeV , 7 TeV [1209.0753]

1

=4.8 fb L

=3, NLO) δ (HLZ

S

M 4.18 TeV

, 7 TeV [1211.1150]

1

=4.7 fb L

=2) δ (

D

M 1.93 TeV

, 7 TeV [1209.4625]

1

=4.6 fb L

=2) δ (

D

M 4.37 TeV

, 7 TeV [1210.4491]

1

=4.7 fb L

Only a selection of the available mass limits on new states or phenomena shown *

1

= ( 1 - 20) fb Ldt

∫

= 7, 8 TeV s

ATLAS

Preliminary

ATLAS Exotics Searches* - 95% CL Lower Limits (Status: May 2013)

34 / 37

SLIDE 35

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Conclusions

◮ ATLAS has performed a wide variety of searches for Supersymmetry using

the Run 1 dataset.

◮ Simplified models have proved very useful in this procedure with several

search strategies a direct consequence of using them eg.

◮ Soft lepton strong production analysis covering compressed scenarios ◮ The variety of stop searches covering the different decay modes ◮ Others...

◮ Details of all SUSY public results can be found here. ◮ Looking forward to an interesting workshop!

35 / 37

SLIDE 36

ATLAS Searches for SUSY

Chris Young, CERN ATLAS Group

Back-Up

36 / 37

SLIDE 37