Searches for squarks and gluinos in all-hadronic ﬁnal ... · Raghavan Rangarajan Sreerup...

Searches for squarks and gluinos in all-hadronic final states with ATLAS

Koichi NAGAIUniversity of Oxford

On behalf of ATLAS collaboration

SUSY 17

National Organising Committee Sudeshna Banerjee Gautam Bhattacharyya Utpal Chattopadhaya Anindya Datta Rajesh Gopakumar Monoranjan Guchait (Convenor) Gobinda Mazumdar Biswarup Mukhopadhaya Sudhakar Panda Anjan Ananda Sen Seema Sharma K. Sridhar Raghavan Rangarajan Sreerup Raychaudhuri (Co-Convenor) V. Ravindran Sudhir Vempati

Important Dates Early registration: Aug 1 – Oct 20, 2017 Late registration:

Oct 21 – Nov 3, 2017

Website: http://www.tifr.res.in/~susy17/

Contact: [email protected]

International Advisory Committee Ignatios Antoniadis

Csaba Balazs Wim de Boer Marcela Carena

Mirjam Cvetic Athanasios Dedes Keith Dienes

Herbi Dreiner John Ellis

Jonathan L. Feng Gian F. Giudice Rohini M Godbole

Kaoru Hagiwara Tao Han

Gordon L. Kane Jihn E. Kim

Pyungwon Ko Paul G. Langacker

Joseph D. Lykken Rabindra N. Mohapatra

Pran Nath Apostolos Pilaftsis

Fernando Quevedo Graham G. Ross

Sandip Trivedi

December 11 – 15, 2017

Searches for squarks and gluinos in all-hadronic final states with ATLASKoichi NAGAI

ATLAS in LHCLarge Hadron Collider (LHC) has been successfully operated at √s = 13 TeV.

A total integrated luminosity of 36.1 fb—1 of proton-proton collision data was collected by the ATLAS experiment with good detector conditions and data quality during 2015 and 2016.

2

Upgrade of ATLAS detector before 13 TeV data taking to improve sensitivity:➡ Insertable B-Layer

(Ave. 3 cm from the beam axis)✓ improved tracking, especially b-tagging

➡ ATLAS High Level Trigger system✓ larger acceptance, while enhancing

rejection๏ Improved ET

miss trigger๏ Improved jet energy scale


SUSY production at LHCSupersymmetry (SUSY) is an extension of Standard Model (SM)

• A solution of hierarchy problem

Assuming R-parity is conserved (RPC),• SUSY particles are pair-produced• Decay to SM particles and the lightest SUSY

particle (LSP).• LSP is stable and weakly interacting.

➡ Missing transverse momentum: ET miss

At LHC, a pair of SUSY particles can be dominantly produced with strong interactions.

• large cross-sections for gluino and squark productions

3

7XVSRK 4VSHYGXMSR

)YV� 4L]W� .� '�� 0,' GVSWW�WIGXMSR [SVOMRK KVSYT;MPP *E[GIXX �9RMZIVWMX] SJ 3\JSVH ��

�/��

Eur.Phys.J. C74 (2014) 12, 3174 LHC cross-section working group


Search channels

4

Searches for 3rd generations are in another talks

squarks/gluinos pair productions+

full hadronic decaysRPC0 lepton

Multi-jets

g̃

g̃

!̃02

!̃±1

p

p

t t

!̃01

Z/h

tb

!̃01

W

Many-step

pMSSM

2-6 jets

1 stepDirect

Gtt/Gbb

Gtt

Gbb


Search strategies

5

Control Regions (CR)• Orthogonal to SR, small

contamination of signals • Enriched a particular BKG• Evaluate BKG MCs' normalisation

factors with BKG only fit

Signal Regions (SR)• Many dedicated SRs constructed by

target signatures using discriminating variables, for example,

• ET miss, Njet, Nb-jets, pT

Jet, MEFF, MJ ∑,

ET miss/√HT, ISR Jet, (➝

pT

jet, ➝ ET miss)min

• Event level variables by Recursive Jigsaw Reconstruction (RJR)

Targets of searches • “Simplified Model”✓ 1 step✓ Many-step✓ Gtt, Gbb

• particular decay modes✓ phenomenological MSSM

(pMSSM)

Validation Regions (VR)

• Close to SR, limited potential signal contamination

• Validate background modelling


2-6jets channel

6




Multi-jets

g̃

g̃

!̃02

!̃±1

p

p

t t

!̃01

Z/h

tb

!̃01

W

Many-step

pMSSM

2-6 jets

1 stepDirect

Gtt/Gbb

Gtt

Gbb


RJR-based search• 19 SRs:

➡ Δm ≡ mP−mI

➡ squark/gluino/compressed decay models

➡ RJR-variables defined by decay models

2-6j: Search strategies

7

https://arxiv.org/abs/1712.02332

LAB

CM

ISR SV I

Lab State

Decay States

Visible States

Invisible States

Compressed

1 stepDirec

Effective mass (MEFF)-based search• MEFF ≡ ∑pT

Jet + ET miss

✓ MEFF ≈ parent sparticle mass• 24 SRs: sparticle mass and final states

➡ ≧ 2, 3, 4, 5 jets: direct decays to LSP➡ ≧ 5,6 jets: 1 step cascade decay with

hadronically decaying W/Z/h bosons➡ ≧ 2 re-clustered large-R jets (R=1.0):

1 step cascade decay with boosted W/Z/h bosons

&m




2-6j: Background Estimation

8

Z + jets Z→νν CR with γ + jetsW + jets W→lν CR with 1 lepton + b-jet vetoTop quark pair Semi-leptonic

decays CR with 1 lepton + b-jet taggingsingle top

Semi-leptonic decays CR with 1 lepton + b-jet tagging

di-boson production MC normalised to NLO cross-section

QCD multi-jet a data driven method with jet smearing

[GeV]CMT S

p200 400 600 800 1000 1200 1400 1600 1800 2000

Even

ts /

200

GeV

1

10

210

310

410

510

610

710 ATLAS -1=13 TeV, 36.1 fbs

for RJR-C1aCR

Data 2015 and 2016

SM Total

+jetsa

W+jets

(+EW) & single toptt

Z+jets

Diboson

[GeV]CMT S

p200 400 600 800 1000 1200 1400 1600 1800 2000

Dat

a / M

C

00.5

11.5

2

Even

ts /

200

GeV

1

10

210

310

410 ATLAS

-1=13 TeV, 36.1 fbsCRT for Meff-4j-2200

Data 2015 and 2016SM Total

(+EW) & single topttW+jetsZ+jetsDibosonMulti-jet

(incl.) [GeV]effm1000 1500 2000 2500 3000 3500 4000

Dat

a / M

C

00.5

11.5

2


RJR Signal RegionRJR

-C1

RJR

-C2

RJR

-C3

RJR

-C4

RJR

-C5

RJR

-G1a

RJR

-G1b

RJR

-G2a

RJR

-G2b

RJR

-G3a

RJR

-G3b

RJR

-G4

RJR

-S1a

RJR

-S1b

RJR

-S2a

RJR

-S2b

RJR

-S3a

RJR

-S3b

RJR

-S4

Even

ts

1

10

210

310

410

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

Z+jetsDibosonMulti-jet

ATLAS-1=13TeV, 36.1 fbs

RJR Signal RegionR

JR-C

1

RJR

-C2

RJR

-C3

RJR

-C4

RJR

-C5

RJR

-G1a

RJR

-G1b

RJR

-G2a

RJR

-G2b

RJR

-G3a

RJR

-G3b

RJR

-G4

RJR

-S1a

RJR

-S1b

RJR

-S2a

RJR

-S2b

RJR

-S3a

RJR

-S3b

RJR

-S4

Dat

a/SM

Tot

al0

0.51

1.5

2

2j-1

200

2j-1

600

2j-2

000

2j-2

100

2j-2

400

2j-2

800

2j-3

600

2jB-

1600

2jB-

2400

3j-1

300

4j-1

000

4j-1

400

4j-1

800

4j-2

200

4j-2

600

4j-3

000

5j-1

600

5j-1

700

5j-2

000

5j-2

600

6j-1

200

6j-1

800

6j-2

200

6j-2

600

Meff Signal Region

1

10

210

310

410

Even

ts

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

Z+jetsDibosonMulti-jet

ATLAS-1=13TeV, 36.1 fbs

2j-1

200

2j-1

600

2j-2

000

2j-2

100

2j-2

400

2j-2

800

2j-3

600

2jB-

1600

2jB-

2400

3j-1

300

4j-1

000

4j-1

400

4j-1

800

4j-2

200

4j-2

600

4j-3

000

5j-1

600

5j-1

700

5j-2

000

5j-2

600

6j-1

200

6j-1

800

6j-2

200

6j-2

600

Meff Signal Region

00.5

11.5

2

Dat

a/SM

Tot

al

2-6j: ResultsNo significant excess

The largest excesses are 2 × 2.0σ in MEFF and 2.5σ RJR(red circles)

9

MEFF RJR

squark1step boosted

gluino 1 step Compressedgluino

squark


2-6j: Interpretations

•Exclusion limit obtained with the SR with the best expected sensitivity at each mass point

10

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

[GeV

]0 1χ∼

m

0

200

400

600

800

1000

1200

1400

01χ∼ < m

q~m

)=100%01χ∼ q → q~(B production, q~q~

ATLAS-1 = 13 TeV, 36.1 fbs

0-leptons, 2-6 jets

MEff or RJR (Best Expected)All limits at 95% CL

)c~,s~,d~,u~ (R

q~+L

q~

)SUSYtheoryσ1 ±Obs. limit (

)expσ1 ±Exp. limits (Exp. limits MEffExp. limits RJR

)-10L obs. limit (13 TeV, 3.2 fb

[GeV]g~m500 1000 1500 2000 2500

[GeV

]0 1χ∼

m

0

200

400

600

800

1000

1200

1400

1600

1800

01χ∼

< m

g~m

)=100%01χ∼ qq → g~(B production, g~g~


0-leptons, 2-6 jets





[GeV]g~m1000 2000 3000 4000 5000 6000

[GeV

]q~

m

1000

2000

3000

4000

5000

6000)=0 GeV0

1χ∼Squark-gluino-neutralino model, m(


0-leptons, 2-6 jetsAll limits at 95% CL

Meff or RJR (Best Expected)

)c~,s~,d~,u~ (R

q~+L

q~

)SUSYtheoryσ1 ±0L obs. limit (

)expσ1 ±Exp. limits (

)-1Observed limit (8 TeV , 20.3 fb

Squark production

Gluino mass

Gluino production

Squa

rk m

ass

Squark mass

LSP

mas

s

Gluino mass

LSP

mas

s


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

[GeV

]0 1χ∼

m

0

200

400

600

800

1000

1200

1400

01χ∼ < m

q~m

)=100%01χ∼ q → q~(B production, q~q~


0-leptons, 2-6 jets


)c~,s~,d~,u~ (R

q~+L

q~




[GeV]g~m500 1000 1500 2000 2500

[GeV

]0 1χ∼

m

0

200

400

600

800

1000

1200

1400

1600

1800

01χ∼

< m

g~m

)=100%01χ∼ qq → g~(B production, g~g~


0-leptons, 2-6 jets





[GeV]g~m1000 2000 3000 4000 5000 6000

[GeV

]q~

m

1000

2000

3000

4000

5000

6000)=0 GeV0

1χ∼Squark-gluino-neutralino model, m(


0-leptons, 2-6 jetsAll limits at 95% CL

Meff or RJR (Best Expected)

)c~,s~,d~,u~ (R

q~+L

q~

)SUSYtheoryσ1 ±0L obs. limit (

)expσ1 ±Exp. limits (

)-1Observed limit (8 TeV , 20.3 fb

2-6j: Interpretations

•Exclusion limit obtained with the SR with the best expected sensitivity at each mass point

•RJR-based SRs improved limits in regions with very compressed spectra

11

Squark production

Gluino mass

Gluino production

Squa

rk m

ass

Squark mass

LSP

mas

s

Gluino mass

LSP

mas

s RJR-Gluino

RJR-CompressedRJR-Compressed

RJR-Squark


Gtt/Gbb channel

12




Multi-jets

g̃

g̃

!̃02

!̃±1

p

p

t t

!̃01

Z/h

tb

!̃01

W

Many-step

pMSSM

2-6 jets

1 stepDirect

Gtt/Gbb

Gtt

Gbb


Gtt/Gbb: IntroductionA search for gluino mediated stop (Gtt)/sbottom (Gbb) productions

• Masses of stop and sbottom are expected to be light to solve the hierarchy problem.

SRs are built by considering event signatures:• Njet ≥ 4 with pT

Jet ≥ 30 GeV

• Nb-jet ≥ 3• Large ET

miss

• ΔM = ⎮Mgluino − MLSP⎮

• MEFF ≡ ∑pT Jet + ∑pT

Lepton + ET miss

For Gtt, followings are also considered• Massive reclustered large-R jet (R=0.8) due to boosted top • Isolated e± or μ± from semi-leptonic top decay

13


Cut-and-count• Maximise discovery power• 6 Gtt & 4 Gbb SRs:

Based on ΔM✓ four &M regions: High,

Moderate, Low, Very low✓ partially overlapping

Multi-bin• Strengthen the exclusion

limit• 14 SRs:

Based on MEFF and Njet✓ non-overlapping

Gtt/Gbb

Gtt

Gbb




Gtt/Gbb: Background Estimation

14

VR0L_IStR_Gtt

VR0L_Lnj_Lmeff_Gtt

VR0L_Lnj_Imeff_Gtt

VR0L_Lnj_Hmeff_Gtt

VR0L_Inj_Lmeff_Gtt

VR1LmT_Inj_Lmeff_Gtt

VR0L_Inj_Imeff_Gtt

VR1LmT_Inj_Imeff_Gtt

VR0L_Hnj_Lmeff_Gtt

VR1LmT_Hnj_Lmeff_Gtt

VR0L_Hnj_Imeff_Gtt

VR1LmT_Hnj_Imeff_Gtt

VR0L_Hnj_Hmeff_Gtt

VR1LmT_Hnj_Hmeff_Gtt

Even

ts

1

10

210

310 Data Total backgroundtt Single top + Xtt W+jets

Z+jets DibosonMultijetMulti-bin analysis

-1=13 TeV, 36.1 fbsATLAS

VR-0L-ISRVR-0L-LL

VR-0L-LIVR-0L-LH

VR-0L-ILVR-1L-IL

VR-0L-IIVR-1L-II

VR-0L-HLVR-1L-HL

VR-0L-HIVR-1L-HI

VR-0L-HHVR-1L-HH

tot

σ) /

pr

ed -

nob

s(n

2−02

VR1_Gtt_1l_A

VR2_Gtt_1l_A

VR1_Gtt_1l_B

VR2_Gtt_1l_B

VR1_Gtt_1l_C

VR2_Gtt_1l_C

VR2_Gtt_0l_A

VR2_Gtt_0l_B

VR2_Gtt_0l_C

VR2_Gbb_AVR2_Gbb_D

VR2_Gbb_BVR2_Gbb_C

Even

ts

1

10

210

310 Data Total backgroundtt Single top + Xtt W+jets

Z+jets DibosonMultijetCut-and-count analysis


-Gtt-1L-BT

VR-m-Gtt-1L-B

b-jetsT,min

VR-m -Gtt-1L-MT

VR-m-Gtt-1L-M

b-jetsT,min

VR-m -Gtt-1L-CT

VR-m-Gtt-1L-C

b-jetsT,min

VR-m VR-Gtt-0L-BVR-Gtt-0L-M

VR-Gtt-0L-CVR-Gbb-B

VR-Gbb-MVR-Gbb-C

VR-Gbb-VC

tot

σ) /

pr

ed -

nob

s(n

2−02

top quark pair MC normalised with top quark pair CRsingle top, 4 tops

MC normalised to the best available cross-section

Z + jets Z→ννMC normalised to the best available cross-section W + jets W→lν MC normalised to the best available cross-section

Top quark pair + W/Z/h


di-boson production


QCD multi-jet a data driven method with jet smearing

Cut-and-count VRs Multi-bin VRs


Gtt/Gbb: Results

No significant excess

The largest excess ≈ 2.3σ in a Multi-bin SR

15

SR_Gtt_1l_ASR_Gtt_1l_B

SR_Gtt_1l_CSR_Gtt_0l_A

SR_Gtt_0l_BSR_Gtt_0l_C

SR_Gbb_ASR_Gbb_D

SR_Gbb_BSR_Gbb_C

Even

ts

1−10

1

10

210

310Data Total backgroundtt Single top + Xtt W+jets

Z+jets DibosonMultijetCut-and-count analysis


SR-Gtt-1L-BSR-Gtt-1L-M

SR-Gtt-1L-CSR-Gtt-0L-B

SR-Gtt-0L-MSR-Gtt-0L-C

SR-Gbb-BSR-Gbb-M

SR-Gbb-CSR-Gbb-VC

tot

σ) /

pr

ed -

nob

s(n

2−02

SR_0l_IStR_Gtt

SR_0l_Lnj_Lmeff_Gtt

SR_0l_Lnj_Imeff_Gtt

SR_0l_Lnj_Hmeff_Gtt

SR_0l_Inj_Lmeff_Gtt

SR_1l_Inj_Lmeff_Gtt

SR_0l_Inj_Imeff_Gtt

SR_1l_Inj_Imeff_Gtt

SR_0l_Hnj_Lmeff_Gtt

SR_1l_Hnj_Lmeff_Gtt

SR_0l_Hnj_Imeff_Gtt

SR_1l_Hnj_Imeff_Gtt

SR_0l_Hnj_Hmeff_Gtt

SR_1l_Hnj_Hmeff_Gtt

Even

ts

1−10

1

10

210

310Data Total backgroundtt Single top + Xtt W+jets

Z+jets DibosonMultijetMulti-bin analysis


SR-0L-ISRSR-0L-LL

SR-0L-LISR-0L-LH

SR-0L-ILSR-1L-IL

SR-0L-IISR-1L-II

SR-0L-HLSR-1L-HL

SR-0L-HISR-1L-HI

SR-0L-HHSR-1L-HH

tot

σ) /

pr

ed -

nob

s(n

2−02

Cut-and-count SRs

Multi-bin SRs


Gtt/Gbb: Interpretations• Interpreted with the simplified model

using multi-bin SRs• New interpretation was done for gluino

branching ratio plane Gtt vs Gbb➡ Assuming three decay gluino’s modes:

Gtt, Gbb, Gtband Br(Gtt) + Br(Gbb) + Br(Gtb) = 100%

16

) [GeV]g~m(1200 1400 1600 1800 2000 2200 2400

) [G

eV]

10 χ∼m

(

0

200

400

600

800

1000

1200

1400

1600

1800

2000Expected limit in 2015Observed limit in 2015

)expσ1 ±Expected limit ()theory

SUSYσ1 ±Observed limit (

t + 2m

01χ∼ < m

g~m

)g~) >> m(q~, m(01χ∼+t t→ g~ production, g~g~

All limits at 95% CL

ATLAS-1=13 TeV, 36.1 fbs

Expected limit in 2015Observed limit in 2015



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 2015Observed limit in 2015


SUSYσ1 ±Observed limit (b + 2m

01χ

∼ < mg~m

)g~) >> m(q~, m(01χ∼+b b→ g~ production, g~g~

All limits at 95% CL


Expected limit in 2015Observed limit in 2015



Gbb

) [%]10χ∼ t t→ g~(B

0 10 20 30 40 50 60 70 80 90 100

) [%

]10 χ∼ b

b→ g~ (

B

0

10

20

30

40

50

60

70

80

90

100

ExpectedObserved

) = 1.8 TeVg~m() = 1.9 TeVg~m() = 2.0 TeVg~m(

) = 100%1-χ∼ b t→ g~(B) + 1

0χ∼ b b→ g~(B) + 1

0χ∼ t t→ g~(B


) = 1 GeV10χ∼m(

Not allowed

LSP

mas

sLS

P m

ass

Gluino mass

Gluino mass


Multi-jet channel

17




Multi-jets

g̃

g̃

!̃02

!̃±1

p

p

t t

!̃01

Z/h

tb

!̃01

W

Many-step

pMSSM

2-6 jets

1 stepDirect

Gtt/Gbb

Gtt

Gbb


Multi-jetMotivation

• Many-step cascade decay of SUSY particles can produce high Njet

• Unique sensitivity to some slices in pMSSM

The final state is characterised with• Moderate ET miss

• Njet ≥ 8 (7) with pT jet ≥ 50 (80) GeV

➡ ET miss Significance: ET

miss/√HT ≥ 5 GeV1/2

Final state with top quarks are considered in Jet mass stream• Sum of mass of re-clustered large-R jet (R=1.0): MJ

∑ ≡ ∑mjR=1.0

18


Heavy flavour stream• 21 SRs:

Njet ≥ 8, 9, 10, 11 (7, 8, 9) with pT

jet > 50 (80) GeVNb-jet ≥ 0, 1, 2✓Good sensitivity to signal

with high LSP mass regions

Jet mass stream• 6 SRs:

Njet ≥ 8, 9, 10 with pTjet > 50

MJ∑ > 340, 500 GeV

✓Good sensitivity to signal with high gluino mass regions

Multi-jets

g̃

g̃

!̃02

!̃±1

p

p

t t

!̃01

Z/h

tb

!̃01

W

Many-step

pMSSM




Multi-jet: Background Estimation

19

QCD multi-jet data driven with “template” method Semi-leptonically decaying top quark pair MC normalised with top quark pair CR

W + jets W→lν MC normalised with W + jets enriched CRZ + jets Z→νν

MC normalised to the best available cross-section single top MC normalised to the best available cross-section

di-boson production


1/2

Num

ber o

f Eve

nts

/ 4 G

eV

10

210

310

410

510

610

710

810

910

10101− = 13 TeV, 36.1 fbs

VR-7j50-0b

ATLAS DataTotal backgroundMultijet

ql, ll→ tt + jetsν l→W

OtherpMSSM benchmark2-step benchmark

]1/2 [GeVTH / missTE

0 2 4 6 8 10 12 14 16 18

Data

/ Pr

ed.

00.5

11.5

2

1/2

Num

ber o

f Eve

nts

/ 4 G

eV

1

10

210

310

410

510

610

710

8101− = 13 TeV, 36.1 fbs

VR-7j50-MJ500





0 2 4 6 8 10 12 14 16 18

Data

/ Pr

ed.

00.5

11.5

2

MJ-Template ≡ Data − Normalised BKG MC

in MetSig distribution at Njet=6

MJ-BKG@“k jets” ≡ MJ-Template × Ratio of Nevent

QCD in low MetSig (<1.5)

between Njet=6 and k

Heavy flavour VR Jet mass VR


Multi-jet: Results

No excess was observed in any SRs

20

1/2

Num

ber o

f Eve

nts

/ 4 G

eV

2−10

1−10

1

10

210

310

410

510

610 1− = 13 TeV, 36.1 fbsSR-11j50-0b





0 2 4 6 8 10 12 14 16 18

Data

/ Pr

ed.

00.5

11.5

2

1/2

Num

ber o

f Eve

nts

/ 4 G

eV

2−10

1−10

1

10

210

310

410

510

610

7101− = 13 TeV, 36.1 fbs

SR-10j50-MJ500





0 2 4 6 8 10 12 14 16 18Da

ta /

Pred

.0

0.51

1.52

Even

ts

10

210

310

410Multijet + jetsi lAW Data

Other ql, llA tt Total Background

8j50

-0b

8j50

-1b

8j50

-2b

9j50

-0b

9j50

-1b

9j50

-2b

10j5

0-0b

10j5

0-1b

10j5

0-2b

11j5

0-0b

11j5

0-1b

11j5

0-2b

7j80

-0b

7j80

-1b

7j80

-2b

8j80

-0b

8j80

-1b

8j80

-2b

9j80

-0b

9j80

-1b

9j80

-2b

8j50

-MJ3

408j

50-M

J500

9j50

-MJ3

409j

50-M

J500

10j5

0-M

J340

10j5

0-M

J500

Dat

a / P

redi

ctio

n

0

0.5

1

1.5

2

ATLAS 1< = 13 TeV, 36.1 fbs

Heavy flavour Jet mass

Heavy flavour Jet mass


) [GeV]g~m(800 1000 1200 1400 1600 1800 2000 2200 2400

) [G

eV]

0 1r¾m

(

200

400

600

800

1000

1200

)01r¾

) = m

(

g~m(

)]/201

r¾)+m(±

1r¾)=[m(0

2r¾)]/2, m(0

1r¾)+m(g~)=[m(±

1r¾; m(0

1r¾ qqWZA g~ production, g~g~

ATLAS Combinedmiss

TMultijets + E

1<=13 TeV, 36.1 fbsAll limits 95% CL

)expm1 ±Expected ()theory

SUSYm1 ±Observed (1<ATLAS 13 TeV, 3.2 fb

Many-step

Multi-jet: Interpretations

Exclusion limit obtained with the SR with the best expected sensitivity at each mass point

21

) [GeV]g~m(1000 1200 1400 1600 1800 2000 2200 2400

) [G

eV]

± 1r¾m

(

200

300

400

500

600

700

8005 TeV5 )l~5 TeV, m( 5)q~=3 TeV, m(

2<0, Mµ=10, `=60 GeV, tan

1pMSSM: M

ATLAS Combinedmiss

TMultijets + E


)expm1 ±Expected (

)theorySUSYm1 ±Observed (

1<ATLAS 13 TeV, 3.2 fb

pMSSM

LSP

mas

s

Char

gino

mas

s

Gluino massGluino mass


Interpretations

22

Multi-jet 2-6 jets Gtt

) [GeV]g~m(500 1000 1500 2000 2500

) [G

eV]

0 1r¾m

(

200

400

600

800

1000

1200

1400

1600

1800ATLAS Preliminary

= 13 TeVs-136.1 fb

01

r¾Wq qAg~

December 2017

0-lepton expected0-lepton observed1-lepton expected1-lepton observedRun 1 expectedRun 1 observed

0-lepton: arXiv:1712.023321-lepton: arXiv:1708.08232Run 1: arXiv:1507.05525

))10

r¾)+m(g~(m(×21) =

1±

r¾m()

10

r¾)<

m(g~

m(

) [GeV]g~m(800 1000 1200 1400 1600 1800 2000 2200

) [G

eV]

0 1r¾m

(

200

400

600

800

1000

1200

1400


-1 = 13 TeV, 36.1 fbs

01

r¾WZq qAg~

December 2017

7-11 jets expected* 7-11 jets observed*

1 lepton expected1 lepton observedSS leptons expectedSS leptons observedRun 1 expectedRun 1 observed

7-11 jets: arXiv:1708.02794*

1 lepton: arXiv:1708.08232SS leptons: arXiv:1706.03731Run 1: arXiv:1507.05525

))1

0r¾)+m(g~(m(×2

1) = 1±

r¾m( ))1

0r¾)+m(

1±

r¾(m(×21) =

2

0r¾m(

) [GeV]g~m(1000 1200 1400 1600 1800 2000 2200 2400 2600

) [G

eV]

0 1r¾m

(

200

400

600

800

1000

1200

1400

1600

1800


-136.1 fb

= 13 TeVs, 01

r¾t tAg~

December 2017

3b jets expected* 3b jets observed*

SS leptons expectedSS leptons observedRun 1 expectedRun 1 observed 3b jets: 1711.01901*

SS leptons: 1706.03731Run 1: arXiv:1507.05525

t)+t1

0r¾

)<m(

g~m(


ConclusionThe proton-proton collision data in 2015 and 2016 collected by ATLAS, corresponding

integrated luminosity of 36.1 fb−1, are fully analysed and the results have been finalised.

Not only relying increased statistics, but also analyses have been improved their sensitivity.

Despite outstanding efforts, the evidence of squarks/gluinos has not appeared yet.

23

) [GeV]g~m(1000 1200 1400 1600 1800 2000

) [G

eV]

0 1r¾m

(

500

1000

1500

2000

2500ATLAS Preliminary -1 = 13 TeV, 36.1 fbs

December 2017

, 0-lepton, arXiv:1712.023320

1r¾q qAg~

, 0-lepton, arXiv:1712.023320

1r¾Wq qAg~

, 1-lepton, arXiv:1708.082320

1r¾Wq qAg~

7-11 jets, arXiv:1708.02794*, 0

1r¾WZq qAg~

, SS leptons, arXiv:1706.037310

1r¾WZq qAg~

, SS leptons, arXiv:1706.037310

1r¾t tAg~

3b jets, arXiv:1711.01901*, 0

1r¾t tAg~

3b jets, arXiv:1711.01901*, 0

1r¾b bAg~

Backup


2-6j: Results

25

Even

ts /

200

GeV

1

10

210

310

410 ATLAS -1=13 TeV, 36.1 fbs

Meff-2j-2100

Data 2015 and 2016

SM Total(+EW) & single toptt

Z+jets

Diboson

Multi-jet direct,q~q~

)=(600, 595)01

r¾

, q~m(

(incl.) [GeV]effm1000 1500 2000 2500 3000 3500 4000

Dat

a / M

C

00.5

11.5

2

Even

ts /

200

GeV

1

10

210

310

ATLAS -1=13 TeV, 36.1 fbs

Meff-2j-2800

Data 2015 and 2016SM TotalW+jets

(+EW) & single topttZ+jetsDibosonMulti-jet

direct,q~q~

)=(1500, 0)01

r¾

, q~m(

(incl.) [GeV]effm1000 1500 2000 2500 3000 3500 4000

Dat

a / M

C

00.5

11.5

2

Even

ts /

200

GeV

1

10

210

310

410 ATLAS

-1=13 TeV, 36.1 fbsMeff-4j-1000



direct,g~g~

)=(1300, 900)01

r¾

, g~m(

(incl.) [GeV]effm1000 1500 2000 2500 3000 3500 4000

Dat

a / M

C

00.5

11.5

2

Even

ts /

200

GeV

1

10

210

310

410 ATLAS

-1=13 TeV, 36.1 fbsMeff-4j-2200



direct,g~g~

)=(1800, 800)01

r¾

, g~m(

(incl.) [GeV]effm1000 1500 2000 2500 3000 3500 4000

Dat

a / M

C

00.5

11.5

2

Even

ts /

200

GeV

1

10

210

310 ATLAS

-1=13 TeV, 36.1 fbsMeff-6j-2600



onestep,g~g~

)=(1705, 865, 25)01

r¾

, ±1

r¾, g~m(

(incl.) [GeV]effm1000 1500 2000 2500 3000 3500 4000

Dat

a / M

C

00.5

11.5

2

Even

ts /

200

GeV

1

10

210

310 ATLAS

-1=13 TeV, 36.1 fbsMeff-2jB-2400



onestep,g~g~

)=(1600, 1590, 60)01

r¾

, ±1

r¾, g~m(

(incl.) [GeV]effm1000 1500 2000 2500 3000 3500 4000

Dat

a / M

C0

0.51

1.52


2-6j: Results

26

1000 1500 2000 2500 3000 [GeV]PP

T 2,1H

1<10

1

10

210

310

410

510

Even

ts /

125

GeV ATLAS

-1=13 TeV, 36.1 fbsRJR-S1a


W+jets

(+EW) & single topttZ+jets

DibosonMulti-jet

direct,q~q~

)=(1100, 500)01

r¾

, q~m(

1000 1500 2000 2500 3000 [GeV]PP

T 2,1H0

0.51

1.52

Dat

a / M

C

1600180020002200240026002800300032003400 [GeV]PP

T 2,1H

1<10

1

10

210

310

410

510

610

Even

ts /

100

GeV ATLAS

-1=13 TeV, 36.1 fbsRJR-S3a


W+jets


DibosonMulti-jet

direct,q~q~

)=(1500, 0)01

r¾

, q~m(

1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 [GeV]PP

T 2,1H0

0.51

1.52

Dat

a / M

C

1000 1500 2000 2500 3000 [GeV]PP

T 4,1H

1<10

1

10

210

310

410

510

610

Even

ts /

125

GeV ATLAS

-1=13 TeV, 36.1 fbsRJR-G1a


W+jets


DibosonMulti-jet

direct,g~g~

)=(1500, 900)01

r¾

, g~m(

1000 1500 2000 2500 3000 [GeV]PP

T 4,1H0

0.51

1.52

Dat

a / M

C

1600180020002200240026002800300032003400 [GeV]PP

T 4,1H

1<10

1

10

210

310

410

510

610

710

Even

ts /

100

GeV ATLAS

-1=13 TeV, 36.1 fbsRJR-G3a


W+jets


DibosonMulti-jet

direct,g~g~

)=(2000, 0)01

r¾

, g~m(

1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 [GeV]PP

T 4,1H0

0.51

1.52

Dat

a / M

C

400 600 800 1000 1200 1400 1600 1800 2000 [GeV]CM

T Sp

1<10

1

10

210

310

410

510

610

Even

ts /

200

GeV ATLAS

-1=13 TeV, 36.1 fbsRJR-C2



direct,g~g~

)=(825, 775)01

r¾

, g~m(

400 600 800 1000 1200 1400 1600 1800 2000 [GeV]CM

T Sp

00.5

11.5

2

Dat

a / M

C

400 600 800 1000 1200 1400 1600 1800 2000 [GeV]CM

T Sp

1<10

1

10

210

310

410

510

Even

ts /

200

GeV ATLAS

-1=13 TeV, 36.1 fbsRJR-C4



direct,g~g~

)=(1000, 800)01

r¾

, g~m(

400 600 800 1000 1200 1400 1600 1800 2000 [GeV]CM

T Sp

00.5

11.5

2

Dat

a / M

C


Gtt/Gbb: Results

27

[GeV]missTE

200 300 400 500 600 700 800 900 1000

Even

ts /

100

GeV

20

40

60

80

100ATLAS

-1=13 TeV, 36.1 fbsGbb-VCCut-and-count analysis

DataTotal backgroundttSingle top + Xtt

Z+jetsW+jetsDibosonMultijet

) = 1200, 100010χ∼), m(g~Gbb: m(

) = 1400, 120010χ∼), m(g~Gbb: m(

[GeV]missTE

200 300 400 500 600 700 800 900 1000

Even

ts /

100

GeV

0.51

1.52

2.53

3.54

4.5 ATLAS-1=13 TeV, 36.1 fbs

1L-IIMulti-bin analysis

DataTotal backgroundtt

Single top + Xtt

Z+jetsW+jetsDiboson

) = 1900, 110χ∼), m(g~Gtt: m(

) = 1900, 60010χ∼), m(g~Gtt: m(

[GeV]missTE

200 300 400 500 600 700 800 900 1000Ev

ents

/ 10

0 G

eV0.5

1

1.5

2

2.5

3

3.5

4ATLAS

-1=13 TeV, 36.1 fbsGtt-1L-BCut-and-count analysis


Single top + Xtt

Z+jetsW+jetsDiboson

) = 1900, 110χ∼), m(g~Gtt: m(

) = 1900, 60010χ∼), m(g~Gtt: m(

[GeV]missTE

200 300 400 500 600 700 800 900 1000

Even

ts /

100

GeV

123456789


0L-HIMulti-bin analysis


Single top + Xtt

Z+jetsW+jetsDibosonMultijets

) = 1900, 110χ∼), m(g~Gtt: m(

) = 1900, 60010χ∼), m(g~Gtt: m(

[GeV]missTE

200 300 400 500 600 700 800 900 1000Ev

ents

/ 10

0 G

eV

2

4

6

8

10 ATLAS-1=13 TeV, 36.1 fbs

0L-HHMulti-bin analysis


Single top + Xtt

Z+jetsW+jetsDibosonMultijets

) = 1900, 110χ∼), m(g~Gtt: m(

) = 1900, 60010χ∼), m(g~Gtt: m(


) [GeV]g~m(900 1000 1100 1200 1300 1400 1500 1600 1700

) [G

eV]

0 1r¾m

(

0

100

200

300

400

500

600

700

800

900

1000

) + 2m(t)0

1r¾

) = m(g~m(

)g~) >> m(q~, m(01

r¾+t tAg~ production, g~g~

ATLAS Combinedmiss

TMultijets + E


)expm1 ±Expected (


Gtt

Multi-jet: Interpretations

Exclusion limit obtained with the SR with the best expected sensitivity at each mass point

28

) [GeV]g~m(400 600 800 1000 1200 1400 1600

) [G

eV]

1t~m

(

400

500

600

700

800

900

1000

1100

1200

) + m

(t)

1t~) =

m(

g~m(

tbs (RPV)At 1t~ Ag~ production, g~g~

ATLAS Combinedmiss

TMultijets + E


)expm1 ±Expected (


RPV

LSP

mas

s

stop

mas

s

Gluino massGluino mass

Searches for squarks and gluinos in all-hadronic ﬁnal ... · Raghavan Rangarajan Sreerup...

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Transcript of Searches for squarks and gluinos in all-hadronic ﬁnal ... · Raghavan Rangarajan Sreerup...