atlas supersymmetry searches - cern

ATLAS Supersymmetry Searches

Michaël Ughettoon behalf of the ATLAS collaboration

Stockholm University

December 6, 2016, KRUGER2016

Ughetto M. ATLAS Supersymmetry Searches 1 / 21

Supersymmetry

Weak-scale supersymmetry is an highly appealing BSM candidate:I all Standard Model (SM) fields are associated to a partner

with ∆s = 12

I can solve the electroweak hierarchy problemI R-Parity Conservation (RPC) implies stability for the Lightest

Supersymmetric Particule (LSP): natural dark mattercandidate

I points to SM-gauges unificationSearching for SUSY is complex:

I SUSY-breaking mechanism needs to be parametrized;I Hundreds of free parameters;I Rich phenomenology and large number of possible

experimental signatures.


The ATLAS Experiment

I Multipurpose collider detectorfor high-precision SMmeasurements and searchesbeyond the SM

I Two magnet systems:solenoidal for inner detectorand toroidal for the muonsystem

I Tracking system for |η| < 2.5: silicon pixels, strips andtransition radiation tracker

I EM and hadronic calorimeters for |η| < 4.9: resp. liquidArgon and scintillating tile

I Muon spectrometer for |η| < 2.7 Month in YearJan Apr Jul

Oct

]1

Deliv

ere

d L

um

inosity [fb

0

5

10

15

20

25

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ATLAS Online Luminosity

= 7 TeVs2011 pp

= 8 TeVs2012 pp

= 13 TeVs2015 pp

= 13 TeVs2016 pp

7/1

6 c

alib

ratio

n


SUSY searches (1/2)

Three main SUSY searches axis:I Strong production: direct

gluino/squark productionI Third generation: direct

stop/sbottom productionI Electroweak: direct

sleptons/gauginos productionfor both RPC and RPV scenarios. 10

-5

10-4

10-3

10-2

10-1

1

10

102

103

104

500 1000 1500 2000 2500 3000 3500

t̃t̃*

q̃q̃

q̃q̃*

g̃g̃

q̃g̃

m [GeV]

σtot

[pb]: pp → SUSY

√s = 13 TeV

NLO+NLL

arXiv:1407.5066v2

I Strong production: highest cross-sections, high mass objects, high jetmultiplicities

I 3rd generation: lower masses, b-jets in the final statesI Electroweak: lowest of cross-sections, low-mass objects, clean signatures


SUSY searches (2/2)

Selection of analysis in this talk

Final State Reference L (fb−1)0L+(2-6)jets+Emiss

T ATLAS-CONF-2016-078 13.3multi b-jets ATLAS-CONF-2016-052 14.8Stop 1L ATLAS-CONF-2016-050 13.32b+Emiss

T 1606.08772 3.2Monojet 1604.07773 3.22/3L ATLAS-CONF-2016-096 14.82τ ATLAS-CONF-2016-093 14.81L+jets (RPV) ATLAS-CONF-2016-094 14.8Long Lived Particles (Pixel+Tile) 1606.05129 3.2

All public results are listed here:

ATLAS Supersymmetry Public Results


https://twiki.cern.ch/twiki/bin/view/AtlasPublic/SupersymmetryPublicResults

Typical SUSY search strategy

I Data selected in the triggerplateau, good data-takingconditions required

I Rely on understanding ofthe SM backgrounds

I Rely on goodunderstanding of thedetector and reconstructionperformance

Combined fit of all regions and backgrounds including systematic,experimental and theoretical uncertainties as nuisance parameters


Strong production: 0L+(≥2-≥6)jets+EmissT [13.3/fb]

g̃

g̃

χ̃02

χ̃02

p

p

q q

χ̃01

Z

qq

χ̃01

Z

I Event selection: no lepton, presence of jets, significant EmissT ;

I Main signal discriminants: meff, Recursive Jigsaw Reconstruction (RJR)variables: HPP

1,1, HPP2,1 and HPP

4,1;I 13 meff signal regions, 17 RJR signal regions.

I For a massless χ̃01: mq̃ > 1.35 TeV and mg̃ > 1.9 TeV

Signal Region

Meff-2j-0800Meff-2j-1200






Meff-6j-2200

Even

ts

1

10

210

310

410Data 2015 and 2016SM TotalW+jetstt(+EW) & single topZ+jetsDibosonMulti-jet

ATLAS Preliminary-1=13TeV, 13.3 fbs

Signal Region







Meff-6j-2200

Dat

a/SM

Tot

al

00.5

11.5

22.5

3

Signal Region

RJR-C1RJR-C2

RJR-C3RJR-C4

RJR-C5RJR-G1a

RJR-G1bRJR-G2a

RJR-G2bRJR-G3a

RJR-G3bRJR-S1a

RJR-S1bRJR-S2a

RJR-S2bRJR-S3a

Even

ts

1

10

210

310

410

510 Data 2015 and 2016SM TotalW+jets(+EW) & single toptt

Z+jetsDibosonMulti-jet

ATLAS Preliminary-1=13TeV, 13.3 fbs

Signal Region

RJR-C1RJR-C2

RJR-C3RJR-C4

RJR-C5RJR-G1a

RJR-G1bRJR-G2a

RJR-G2bRJR-G3a

RJR-G3bRJR-S1a

RJR-S1bRJR-S2a

RJR-S2bRJR-S3a

Dat

a/SM

Tot

al

00.5

11.5

22.5


Strong production: 0L+(≥2-≥6)jets+EmissT [13.3/fb]

g̃

g̃

χ̃02

χ̃02

p

p

q q

χ̃01

Z

qq

χ̃01

Z

I Event selection: no lepton, presence of jets, significant EmissT ;

I Main signal discriminants: meff, Recursive Jigsaw Reconstruction (RJR)variables: HPP

1,1, HPP2,1 and HPP

4,1;I 13 meff signal regions, 17 RJR signal regions.I For a massless χ̃0

1: mq̃ > 1.35 TeV and mg̃ > 1.9 TeV

[GeV]q~m400 600 800 1000 1200 1400 1600

[GeV

]0 1χ∼

m

0

200

400

600

800

1000

1200

01χ∼

< mq~m

)=100%0

1χ∼ q → q~(B production, q~q~

ATLAS Preliminary-1 = 13 TeV, 13.3 fbs

0-leptons, 2-6 jets

All limits at 95% CL

MEff or RJR (Best Expected)

)SUSYtheoryσ1 ±Obs. limit (

)expσ1 ±Exp. limits (

Exp. limits MEff

Exp. limits RJR

, 8 TeV)-1Obs. limit (20.3 fb

, 2015)-1Obs. limit (3.2 fb

[GeV]g~m400 600 800 1000 1200 1400 1600 1800 2000

[GeV

]0 1χ∼

m

0

200

400

600

800

1000

1200

1400

1600

01χ∼

< m

g~m

)=100%0

1χ∼ qq → g~(B production, g~g~


0-leptons, 2-6 jets


MEff or RJR (Best Expected)

)SUSYtheoryσ1 ±Obs. limit (

)expσ1 ±Exp. limits (

Exp. limits MEff

Exp. limits RJR

, 8 TeV)-1Obs. limit (20.3 fb

, 2015)-1Obs. limit (3.2 fb


Strong production: multi b-jets (1/2) [14.8/fb]

g̃

g̃p

p

χ̃0

1

b

b

χ̃0

1

b

b

Gbb event selection:I ≥4 jets, ≥3 b-jets, no

leptonsI m4j

eff, EmissT

Gtt event selection:I ≥8 jets, ≥(3-4) b-jets, possible leptonsI mincl

eff , mb-jetsT,min, N b-tag, N top, Emiss

T

SR_Gbb_A SR_Gbb_B SR_Gtt_0l_A SR_Gtt_0l_B SR_Gtt_1l_A SR_Gtt_1l_B SR_Gtt_1l_C

Eve

nts

5

10

15

20

25

30 Data Total backgroundtt Single top + Xtt W+jets

Z+jets Diboson

-1=13 TeV, 14.8 fbs

PreliminaryATLAS

SR-Gbb-A SR-Gbb-B SR-Gtt-0L-A SR-Gtt-0L-B SR-Gtt-1L-A SR-Gtt-1L-B SR-Gtt-1L-C

tot

σ)

/ pr

ed -

nob

s(n

2−

0

2

7 signal regions:I 2 all-hadronic Gbb for large and

small mass splittingI 2 all-hadronic Gtt for large and

small mass splittingI 3 semileptonic Gtt for large,

moderate and small masssplitting


Strong production: multi b-jets (2/2) [14.8/fb]

No excess observed:I For mχ̃0

1= 0 to mχ̃0

1' 700 GeV:

I mg̃ > 1.89 TeV for GbbI mg̃ > 1.89 TeV for Gtt

) [GeV]g~m(1200 1400 1600 1800 2000 2200

) [G

eV]

10 χ∼m

(

0

200

400

600

800

1000

1200

1400

1600

1800

2000Expected limit in 2015

Observed limit in 2015

)expσ1 ±Expected limit (

)theorySUSYσ1 ±Observed limit (b

+ 2m0

1χ∼ < mg~m

)g~) >> m(q~, m(0

1χ∼+b b→ g~ production, g~g~


PreliminaryATLAS-1=13 TeV, 14.8 fbs

Expected limit in 2015



)theorySUSYσ1 ±Observed limit (

) [GeV]g~m(1200 1400 1600 1800 2000 2200

) [G

eV]

10 χ∼m

(

0

200

400

600

800

1000

1200

1400

1600

1800

2000Expected limit in 2015




t + 2m

0

1χ∼ < mg~m

)g~) >> m(q~, m(0

1χ∼+t t→ g~ production, g~g~


PreliminaryATLAS-1=13 TeV, 14.8 fbs

Expected limit in 2015





Third generation: stop 1L (1/2) [13.2/fb]

t̃1

t̃1p

p

χ̃01

t

χ̃01

t

t̃1

t̃1

χ̃±1

χ̃∓1

p

p

b

χ̃01

W±

b

χ̃01

W∓

dark matter benchmark models for early lhc run-2 searches:report of the atlas/cms dark matter forum 39

f/a

g

g

t(b)

c

c̄

t̄(b̄)Figure 2.22: Representative Feynmandiagram showing the pair productionof Dark Matter particles in associationwith tt̄ (or bb̄).

the pMSSM) privilege the coupling of spin-0 mediators to downgeneration quarks. This assumption motivates the study of finalstates involving b-quarks as a complementary search to the tt̄+DMmodels, to directly probe the b-quark coupling. An example of sucha model can be found in Ref. [BFG15] and can be obtained by re-placing top quarks with b quarks in Fig. 2.22. Note that, becauseof the kinematics features of b quark production relative to heavy tquark production, a bb̄+DM final state may only yield one experi-mentally visible b quark, leading to a mono-b signature in a modelthat conserves b flavor.

Dedicated implementations of these models for the work ofthis Forum are available at LO+PS accuracy, even though the stateof the art is set to improve on a timescale beyond that for earlyRun-2 DM searches as detailed in Section 4.1.5. The studies in thisSection have been produced using a leading order UFO modelwithin MadGraph5_aMC@NLO 2.2.2 [Alw+14; All+14; Deg+12]using pythia 8 for the parton shower.

2.2.3.1 Parameter scan

The parameter scan for the dedicated tt̄+/ET searches has been stud-ied in detail to target the production mechanism of DM associatedwith heavy flavor quarks, and shares many details of the scan forthe scalar model with a gluon radiation. The benchmark pointsscanning the model parameters have been selected to ensure thatthe kinematic features of the parameter space are sufficiently rep-resented. Detailed studies were performed to identify points in them

c

, mf,a, g

c

, gq (and Gf,a) parameter space that differ significantly

from each other in terms of expected detector acceptance. Becausemissing transverse momentum is the key observable for searches,the mediator pT spectra is taken to represent the main kinemat-ics of a model. Another consideration in determining the set ofbenchmarks is to focus on the parameter space where we expectthe searches to be sensitive during the 2015 LHC run. Based on aprojected integrated luminosity of 30 fb�1 expected for 2015, wedisregard model points with a cross section times branching ratiosmaller than 0.1 fb, corresponding to a minimum of one expectedevent assuming a 0.1% efficiency times acceptance.

The kinematics is most dependent on the masses mc

and mf,a.

Figure 2.23 and 2.24 show typical dependencies for scalar and

I Event selection: 1 lepton, at least 2 jets, largeEmiss

T

I Main signal discriminants: EmissT , Hmiss

T,sig, mT,aMT2, topness, large-R jet mass

I 2 SR for t̃ → tχ̃01

I 3 SR for t̃ → bχ̃±1

I 2 SR for tt+dark-matter

0 0.0480.0950.1430.190.2380.2860.3330.3810.4290.4760.5240.5710.6190.6670.7140.7620.810.8570.9050.952 1

Eve

nts

1

10

210

310

410

510 DataTotal SMtt

W+jets+Vtt

WtDibosonZ+jets


TVR_SR1WVR_SR1

TVR_tN_high

WVR_tN_high

TVR_DM_low

WVR_DM_low

TVR_DM_high

WVR_DM_high

TVR_bC2x_med

WVR_bC2x_med

TVR_bC2x_diag

WVR_bC2x_diag

TVR_bCbv

WVR_bCbv

SR1 tN_highDM_low

DM_highbC2x_med

bC2x_diagbCbv

tot

σ)

/ ex

p -

nob

s(n

2−024


Third generation: stop 1L (2/2) [13.2/fb]

I 3.3σ excess in DM_lowI For a massless χ̃0

1, mt̃1 > 830 GeVI Assuming a 1 GeV DM mass, scalar

mediator mass is excluded up to320 GeV

[GeV]φm0 50 100 150 200 250 300 350 400 450 500

[GeV

]χ

m

020406080

100120140160180200

Observed limit)expσ1±Expected limit (

Contours for g=3.5

3.3

1.92.1

3.2

1.8

1.7

3.4

3.0

2.5

2.43.1

2.4

2.0

2.1

χ

> 2 m

φm

= gq

= gχ

DM+tt scalar mediator, g


Lim

it on

g

[GeV]1t

~

m200 300 400 500 600 700 800 900 1000

[GeV

]0 1χ∼

m

0

100

200

300

400

500

600

700

< 0t

- m01χ∼

- m1t~ m

0

1χ∼t+→1t

~ production, 1t

~1t

~

)thσ1±Observed limit (

)expσ1±Expected limit (

)-18 TeV + 13 TeV (3.2 fbATLAS stop1L


Limit at 95% CL

[GeV]1t

~

m200 300 400 500 600 700 800 900

[GeV

]0 1χ∼

m

50

100

150

200

250

300

350

400

450

)1

0χ∼ m×

= 2

1±χ∼ ( m

1±χ∼+m

b < m1t~m

1

0χ∼ m× = 2 ±

1χ∼

, m1

±χ∼b+→1t~

production, 1t~1t

~

)thσ1±Observed limit ()expσ1±Expected limit (

ATLAS stop1L 8 TeV


Limit at 95% CL


Third generation: 2 b-jets + met [3.2/fb]I Pair-production of sbottom, both decaying to b+χ̃01I Event selection: no lepton, 2-4 jets, 2 b-jets, large Emiss

TI Main signal discriminants: mCT, mbb, Emiss

T /meffI 4 signal regions with no observed excessI For a massless χ̃01, mb̃1 > 840 GeV

Events

/ 5

0 G

eV

5

10

15

20

25

30

35

40

SRA250

ATLASATLAS1 = 13 TeV, 3.2 fbs

Data SM totaltt

Single topOthers

W + jetsZ + jets

(1)0

1χ∼(700),

1b~

[GeV]CT

m0 100 200 300 400 500 600

Data

/ S

M

0

1

2

[GeV]1

b~m

100 200 300 400 500 600 700 800 900 1000 1100

[G

eV

]0 1

χ∼m

0

100

200

300

400

500

600

700

800

= 8 TeVs, 1

+ 2 bjets, 20.1 fbmiss

T ATLAS E

= 13 TeVs, 1

ATLAS monojet, 3.2 fb

= 8 TeVs, 1

ATLAS monojet, 20.3 fb

)theory

SUSYσ1 ±Observed limit (


0

1χ∼ b →

1b~

Bottom squark pair production,

1=13 TeV, 3.2 fbs

ATLAS

All limits at 95% CLAll limits at 95% CL

Best SR

forb

idde

n

0

1χ∼ b

→

1b~


Monojet analysis [3.2/fb]I compressed squarks-LSP scenario: squark decay

products too soft to be separated from multijetbackground

I ISR jet can boost the squark-squark system: high-pTjet and additional jets

I Signal regions defined with increasing EmissT

thresholds: 7 inclusive SR and 6 exclusive SR

Even

ts /

50 G

eV

2<10

1<10

1

10

210

310

410

510

610

710 ATLAS-1 = 13 TeV, 3.2 fbs

Signal Region>250 GeV miss

T>250 GeV, E

Tp

Data 2015Standard Model

) + jetsii AZ() + jetsio AW() + jetsiµ AW() + jetsi eAW(

ll) + jetsAZ(Dibosons

+ single toptt) = (350, 345) GeV0

r¾, b~m()= (150, 1000) GeV

med, M

DM(m

=5600 GeVD

ADD, n=3, M

[GeV]missTE

400 600 800 1000 1200 1400

Dat

a / S

M

0.5

1

1.5

[GeV]1t

~m260 280 300 320 340 360 380 400 420 440

[GeV

]10 r¾

m

150

200

250

300

350

400

450

-1 = 13 TeV, 3.2 fbs

10

r¾ cA1t~ production, 1t

~1t

~


ATLAS

)theorySUSYm1 ±Observed limit (

)expm1 ±Expected limit (

= 8 TeVsATLAS

c + m0

1r¾ < m1t~m

W + mb + m

01r¾ > m

1t~m


EWK production: 2/3 e/µ + EmissT (1/2) [13.3/fb]I Event selection: exactly two opposite

sign leptons, jet veto or three leptonsand a b-jet veto

I Main signal discriminants: EmissT , mT

and mT2

I six 2 leptons SR and two 3 leptons SR

Events

2−10

1−10

1

10

210

310

410

510

610Data

VV

Top Quark

Other

Reducible

Bkg. Uncert.

) = (500,0) GeV0

1χ

,m±

1χ

(m

Preliminary ATLAS

1 = 13 TeV, 13.3 fbs

µµee+

[GeV]T2m

100 120 140 160 180 200

Da

ta /

MC

0.51

1.52

Events

2−10

1−10

1

10

210

310

410

510Data

VV

VVV

Vtt

Reducible

Bkg. Uncert.

) = (800,600) GeV0

1χ

,m0

2χ/±

1χ

(m

Preliminary ATLAS

1 = 13 TeV, 13.3 fbs

eµµ+µ+eeµµµeee+

[GeV]miss

TE

0 20 40 60 80 100 120 140 160 180 200

Da

ta /

MC

0.51

1.52


EWK production: 2/3 e/µ + EmissT (2/2) [13.3/fb]

No excess observedI For mχ̃0

1= 100 GeV:

I mχ̃±1>650 GeV for χ̃±1 χ̃

∓1 production

I mχ̃±1 ,χ̃

02>1000 GeV for χ̃±1 χ̃02 production

[GeV]±

1χ∼

m100 200 300 400 500 600 700

[G

eV

] 0 1

χ∼m

0

50

100

150

200

250

300

350

400

450

Preliminary ATLAS

= 13 TeVs, 1

Ldt = 13.3 fb∫0

1χ∼ν l× 2 →l) ν∼(νl

~ × 2 →

1χ∼

+

1χ∼

)/2±

1χ∼

+ m0

1χ∼

m = ( Ll~

m

)theory


)exp

σ1 ±Expected limit (

2l ATLAS 8TeV

[GeV]±

1χ∼

m200 400 600 800 1000 1200

[G

eV

]0 1

χ∼m

200

300

400

500

600

700

800

)ν ν∼l (Ll~ ν∼), l ν ν∼l(

Ll~ ν

Ll~ →

0

2χ∼

±

1χ∼

0

1χ∼) ν ν l l (

0

1χ∼ ν l →

)/20

2χ∼

+ m0

1χ∼

m = ( Ll

~

m

0

2χ∼

= m±

1χ∼

m

=13 TeVs, 1

L dt = 13.3 fb∫ATLAS Preliminary

)theory


)exp

σ1 ±Expected limit (

3l ATLAS 8 TeV


EWK production: 2 τ + EmissT (1/2) [14.8/fb]

χ̃±1

χ̃∓1

τ̃ /ν̃τ

τ̃ /ν̃τ

p

p

ντ/τ

τ/ντ

χ̃01

ντ/τ

τ/ντ

χ̃01

χ̃±1

χ̃02

τ̃ /ν̃τ

τ̃ /ν̃τ

p

p

ντ/τ

τ/ντ

χ̃01

τ/ντ

τ/ντ

χ̃01

I Event selection: hadronicallydecaying τ , b-jets veto, Z-veto

I Main signal discriminants: EmissT

and mT2I Two signal regions

[GeV]T2m

20 40 60 80 100 120 140 160 180

Eve

nts

/ 30

GeV

1−10

1

10

210

310

410

510DataSM TotalMulti-jetsW+jetsDibosonTop QuarkZ+jets

) = (400, 0) GeV0

2χ∼

, m±1

χ∼(m

) = (400, 0) GeV±1

χ∼, m±

1χ∼

(m

-1 = 13 TeV, 14.8 fbs

PreliminaryATLAS

[GeV]T2m20 40 60 80 100 120 140 160 180 D

ata/

SM

00.5

11.5

2

[GeV]T2m

20 40 60 80 100 120 140 160 180

Eve

nts

/ 30

GeV

1−10

1

10

210

310

410

510DataSM TotalMulti-jetsW+jetsDibosonTop QuarkZ+jets

) = (400, 0) GeV0

2χ∼

, m±1

χ∼(m

) = (400, 0) GeV±1

χ∼, m±

1χ∼

(m

-1 = 13 TeV, 14.8 fbs

PreliminaryATLAS

[GeV]T2m20 40 60 80 100 120 140 160 180 D

ata/

SM

00.5

11.5

2


EWK production: 2 τ + EmissT (2/2) [14.8/fb]

No excess observedI For a massless χ̃01:

I mχ̃±1>580 GeV for χ̃±1 χ̃

∓1 production

I mχ̃±1 ,χ̃

02>700 GeV for χ̃±1 χ̃02 production

[GeV]±1

χ∼m100 200 300 400 500 600 700 800

[GeV

]0 1χ∼

m

0

50

100

150

200

250

300

350

400



arXiv:1407.0350Observed limit

(103.5 GeV)±1

χ∼LEP2

)/2±

1χ∼

+m0

1χ∼

=(mτ∼m)theory




(103.5 GeV)±1

χ∼LEP2

-1=13 TeV, 14.8 fbs

SR-C1C1




(103.5 GeV)±1

χ∼LEP2

10

χ∼

< m

1±

χ∼m

0

1χ∼ντ × 2 →) τν∼(ντ∼ × 2 →

±

1χ∼±

1χ∼


ATLAS Preliminary

[GeV]0

2χ∼

,m±

1χ∼m

100 200 300 400 500 600 700 800

[GeV

]0 1χ∼

m

0

50

100

150

200

250

300

350

400




(103.5 GeV)±1

χ∼LEP2

)/2±

1χ∼

+m0

1χ∼

=(mτ∼m

0

2χ∼

=m±

1χ∼m




(103.5 GeV)±1

χ∼LEP2

-1=13 TeV, 14.8 fbs

SR-C1N2




(103.5 GeV)±1

χ∼LEP2

10

χ∼

< m

1±

χ∼m

0

1χ∼ντ × 2 →) τν∼(ντ∼ × 2 →

±

1χ∼±

1χ∼

0

1χ∼)νν(ττ 0

1χ∼ντ →) νν∼(ττ∼ν∼τ), νν∼(ττ∼ντ∼ → 0

2χ∼±

1χ∼


ATLAS Preliminary


RPV 1L multijet (1/2) [14.8/fb]

g̃

g̃

χ̃01

χ̃01

p

p

t t̄

λ′′112

u

ds

t t̄

λ′′112

sdu

g̃

g̃

t̃

t̃

p

p

t̄

λ′′323

s̄

b̄

t̄

λ′′323

s̄

b̄

I Event selection: at least 1 lepton andat least 5 jets

I Events categorized in two dimensions:I 6 jet multiplicity bins;I 5 b-jet multiplicity bins.

I 30 bins, simultaneously fitted for BSMmodel-dependent limits.

b-tagsN0 1 2 3 4≥

Eve

nts

0

50

100

150Datatt

+ JetsW + JetsZ

Multi-jetOthers

-1 = 13 TeV, 14.8 fbs

> 60 GeV)T

8 jets (p

ATLAS Preliminary) = 675 GeV

1

0χ∼) = 1.7 TeV, m(g~m(

MC/Model

b-tagsN0 1 2 3 4≥

Dat

a/M

odel

0.5

1

1.5b-tagsN

0 1 2 3 4≥

Eve

nts

0

2

4

6

8

Datatt

+ JetsW + JetsZ

Multi-jetOthers

-1 = 13 TeV, 14.8 fbs

> 60 GeV)T

10 jets (p≥

ATLAS Preliminary) = 675 GeV

1

0χ∼) = 1.7 TeV, m(g~m(

MC/Model

b-tagsN0 1 2 3 4≥

Dat

a/M

odel

0.5

1

1.5


RPV 1L multijet (2/2) [14.8/fb]

I For mχ̃01

= 500 GeV:

I Assuming λ′′112 is the only non-zero RPV coupling:mg̃ > 1.75 TeV

I Assuming λ′′323 is the only non-zero RPV coupling:mg̃ > 1.4 TeV

) [GeV]g~m(

1200 1400 1600 1800 2000

) [G

eV]

10 χ∼m

(

0

500

1000

1500

2000 -1 = 13 TeV, 14.8 fbs)

theorySUSYσ 1 ±Observed limit (

)expσ 1 ±Expected limit (

udst t→ 1

0χ∼ t t→ g~

)1

0χ∼

2 m(t) + m(

≤) g~m(


ATLAS Preliminary

) [GeV]g~m(

600 800 1000 1200 1400 1600

) [G

eV]

t~m

(

600

800

1000

1200

1400 -1 = 13 TeV, 14.8 fbs)

theorySUSYσ 1 ±Observed limit (

)expσ 1 ±Expected limit (

tbs→ t~ t→ g~

m(t)

≤) g~m

(


ATLAS Preliminary


Long Lived Particles (R-hadrons) [3.2/fb]I R-hadrons: long-lived, charged colorless bound state of gluino/squarks

with SM quarks or gluonsI Expected to have low velocity β = v/c, and higher dE/dXI Exploited by using the pixel detector and the tile calorimeter timingI Events selected with large Emiss

T and isolated tracksI Excludes gluino R-hadrons masses lower than 1580 GeV

0

1

2

3

4

5

6

[GeV]βm0 500 1000 1500 2000 2500

[GeV

]γβ

m

0

500

1000

1500

2000

2500ATLAS

-1 = 13 TeV, 3.2 fbs

est. backgroundobs. data

(1000 GeV gluino)exp. signal

[GeV]gluinom600 800 1000 1200 1400 1600 1800 2000

Cro

ss s

ectio

n [fb

]

1

10

210

310

410ATLAS

-1 = 13 TeV, 3.2 fbs

theory prediction limitσ1±expected limitσ2±expected

observed limit = 8 TeV theory predictions

observed-1 = 8 TeV, 19.1 fbs


Conclusion

I Presented a selection of SUSY analyses performed on the2015 ATLAS dataset (3.2 fb−1), or the first-half of the 2016dataset (13-14 fb−1);

I Many other results already available:ATLAS Supersymmetry Public Results;

I No significant excess observed;I Much more results to come with the full 2016 dataset

('36 fb−1 recorded).


https://twiki.cern.ch/twiki/bin/view/AtlasPublic/SupersymmetryPublicResults

atlas supersymmetry searches - cern

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