ATLAS SUSY search in 0-lepton channel with boosted W bosons
Tomas Javureksupervised by:
Gregor Herten, Zuzana Rurikova, Valerio ConsortiUniversity of Freiburg
30th April 2014
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 1 / 18
Introduction
Ongoing events:
paper in Atlas circulation: (ATL-COM-PHYS-2014-094)
int note: (ATL-COM-PHYS-2013-1224)
presented at Atlas Weekly: (https://indico.cern.ch/event/286459/)
today’s open presentation: (https://indico.cern.ch/event/315963/)
In preparation:
pMSSM legacy paper (RunI)
prospects for RunII: (https://indico.cern.ch/event/315501/)
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 2 / 18
Supersymmetry
supersymmetry:
symmetry of Lagrangianresulting to new particlesand interactions
has to be broken (similarto electroweaksymmetry)
Theoretical motivations forSUSY searches:
dark matter
gauge couplingunification
hierarchy problem
Motivation for SUSY searcheswith ATLAS:
reachable sparticlesproduction cross-section
sensitivity to othertheories (searching for
discrepancy between SM
and data in general)
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 3 / 18
Definition of ”susy 0-lepton” analysis
proton proton
jet1
jet2
NOlepton!!!
jet3
MET
MissingE
g̃
g̃
χ̃±1
χ̃∓1
p
p
q q
χ̃01
W
χ̃01
W
q̃
q̃p
p
χ̃01
q
χ̃01
q
0-lepton Signal Regions (SRs):
jets: q̃,g̃ decay to q and gmaking jetsMET: because of R-parityconservation, LSP does notdecay further and contributes toMETlepton veto: to be orthogonal toother SUSY analysis
Aiming signals: mSUGRA,simplified models (gg-onestep onthe left), MUED, NUHMG
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 4 / 18
Selection criteria
ATLAS Work in progress
RequirementChannel
2j 3j 4j 5j 6j2jl 2jm 2jt 2jw 3j 4jw 4jvl 4jl 4jm 4jt 5j 6jl 6jm 6jt 6jvt
Targetted signalq̃q̃ g̃ g̃ q̃g̃ q̃q̃ q̃q̃ q̃q̃ & g̃ g̃ q̃q̃ g̃ g̃
NUHMdirect one-step direct one-step direct one-step one-step
E missT [GeV] > 160
pT(j1) [GeV] > 130pT(j2) [GeV] > 60p(j3) [GeV] > – 60 40 60 60 60
pT(j4) [GeV] > – – 40 60 60 60pT(j5) [GeV] > – – 60 60pT(j6) [GeV] > – – – 60
∆φ(j1,2,(3), E missT > 0.4
∆φ(ji>3, E missT ) > – 0.2
W candidates –2 W → j
–1 W → j
–1 W → jj
E missT /
√HT > 8 15 15 10 10
E missT /meff(Nj) > 0.35 0.3 0.25 0.4 0.25 0.2 0.2 0.2 0.25 0.15
meff(incl.) [GeV] > 800 1200 1600 1800 2200 1100 700 1000 1300 2200 1200 700 1200 1500 1700
Definition of W candidates will come later in this talk.
Powerful executing variables: ETmiss ,mmeff =∑
pT + ETmiss ,ETmiss/mmeff
Two W signal regions SR2jW and SR4jW have been newly developed.
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 5 / 18
Hadronic boosted W Introduction g̃
g̃
χ̃±1
χ̃∓1
p
p
q q
χ̃01
W
χ̃01
W
There are two Ws present in one-step
simplified models.
They mostly decay hadronically:
W → qq̄ (∼ 68%) .
They can be highly boosted for large
values of ∆m(χ̃± − χ̃0) (⇒x∼1 for
LSP=60GeV)
We defined resolved W = 2 jets and
unresolved W = 1 jet (AntiKt0.4)
(right fig.)
We try to reconstruct Ws in the final
state using the windows in the
invariant mass of one or two jets
(next slide).
χ̃−
χ̃0
W−
q̄
q
Jet
χ̃−χ̃−
χ̃−
χ̃0
W−
q̄
q
Jet2
Jet1
Resolved
Unresolved
W-finderFind unresolved Ws among
the jets. y Find resolved Ws
as a combination of two
closest jets in ∆R among
rest of the jets.
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 6 / 18
Hadronic boosted W Introduction
(W)TP0 100 200 300 400 500 600 700 800 900 1000
R∆
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8ATLAS Work in progress
truth level study(W)
T) vs. Pq R(q,∆
=1200 GeV g~
m
=360 GeVχ ~
m
=60 GeVLSPm
squark→chargino→LSP,m(LSP) =60[GeV]
(W)TP0 100 200 300 400 500 600 700 800 900 1000
R∆
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8ATLAS Work in progress
truth level study(W)
T) vs. Pq R(q,∆
=1200 GeV g~
m
=1060 GeVχ ~
m
=60 GeVLSPm
gluino→chargino→LSP,m(LSP) =60[GeV]
We have been using AntiKt0.4 jets so far to be consistent with previous0-lepton analysis. The plan is to switch to AntiKt1.0
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 7 / 18
Hadronic boosted W Introduction
Distribution of invariant mass for
candidates on resolved W when
N(unres.W ) ≥ 1
⇒ 60-100 GeV window was used to
reconstruct W
⇒ SR2jw: N(unres.W ) ≥ 2
⇒ SR4jw: N(unres.W ) ≥ 1, N(res.W ) ≥ 1
Alternative statistical treatmentBackground can be fitted by quadratic
function and χ2-test can be used to
test hypothesis of signal.
) [GeV]k,ji
m(j0 20 40 60 80 100 120 140 160 180 200 220
events
/6GeV
1
10
-1L dt=20.3 fb∫
=8TeV)sData 2012 (
SM Total
)=600
1χ∼
)=1150,m(±
1χ∼
)=1200,m(g~
m(g~
g~
)=600
1χ∼
)=675,m(±
1χ∼
)=700,m(q~
m(q~
q~
Multijet
Z+jets
W+jets
(+X) &single toptt
Diboson
Work in progressATLAS
SR - 4 jets
) [GeV]k,ji
m(j0 20 40 60 80 100 120 140 160 180 200 220D
ATA/MC
00.51
1.52
2.5
Mass of 2 jets [GeV]0 50 100 150 200 250 3000
5
10
15
20
25
30
35
40
all BG
quadr.+N*sigMC fit MC BG
quadr.+sigMC fit MC BG
SM_SS_onestep_600_575_60
Validation Region
not used for fit
+bx+c+sigMC)= 11.982(ax2χ
+bx+c+N.sigMC)= 2.912(ax2χ
+bx+c+N.sigMC) in VR= 1.032(ax2χ
0.30±N= 0.10
Work in progressATLAS-1
L dt = 20.3 fb∫
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 8 / 18
Interesting distributions for 2jW region
) [GeV]i
m(j40 60 80 100 120 140 160 180 200 220
events/6GeV
1
10
210
310
410 -1L dt = 20.3 fb∫
= 8 TeV)sData 2012 (
SM Total
)=600
1χ∼
)=1150,m(±1
χ∼
)=1200,m(g~
m(g~g~
)=600
1χ∼
)=675,m(±1
χ∼
)=700,m(q~
m(q~q~
Multijet
Z+jets
W+jets
(+X) & single toptt
Diboson
Work in progressATLAS
SR - 2 jets
) [GeV]i
m(j40 60 80 100 120 140 160 180 200 220D
ATA/MC
00.51
1.52
2.5
mass of whichever jet in 2jet SRs
) [GeV]i
m(j40 60 80 100 120 140 160 180 200 220
events/6GeV
1
10
210 -1L dt = 20.3 fb∫
= 8 TeV)sData 2012 (
SM Total
)=600
1χ∼
)=1150,m(±1
χ∼
)=1200,m(g~
m(g~g~
)=600
1χ∼
)=675,m(±1
χ∼
)=700,m(q~
m(q~q~
Multijet
Z+jets
W+jets
(+X) & single toptt
Diboson
Work in progressATLAS
SR - 2 jets
) [GeV]i
m(j40 60 80 100 120 140 160 180 200 220D
ATA/MC
00.51
1.52
2.5
mass of whichever jet, 1 unresolved Wrequired, 2jet SRs
)jets
(Neff
/mmiss
TE
0 0.2 0.4 0.6 0.8 1 1.2
events/0.04
1
10
210
-1L dt = 20.3 fb∫
= 8 TeV)sData 2012 (
SM Total
)=600
1χ∼
)=1150,m(±1
χ∼
)=1200,m(g~
m(g~g~
Multijet
Z+jets
W+jets
(+X) & single toptt
Diboson
Work in progressATLAS
SR - 2 jets (W)
2jW
)jets
(Neff
/mmiss
TE0 0.2 0.4 0.6 0.8 1 1.2D
ATA/MC
00.51
1.52
2.5
E missT /meff distribution for 2jW region
(incl.) [GeV]effm0 500 1000 1500 2000 2500 3000 3500 4000
events/420GeV
1
10
-1L dt=20.3 fb∫
=8TeV)sData 2012 (
SM Total
)=600
1χ∼
)=1150,m(±
1χ∼
)=1200,m(g~
m(g~g~
Multijet
Z+jets
W+jets
(+X) &single toptt
Diboson
Work in progressATLAS
SR - 2 jets (W)
2jW
(incl.) [GeV]effm0 500 1000 1500 2000 2500 3000 3500 4000D
ATA/MC
00.51
1.52
2.5
meff distribution for 2jW region
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 9 / 18
Interesting distributions for 4jW region
) [GeV]i
m(j40 60 80 100 120 140 160 180 200 220
events/6GeV
1
10
210
310
-1L dt = 20.3 fb∫
= 8 TeV)sData 2012 (
SM Total
)=600
1χ∼
)=1150,m(±1
χ∼
)=1200,m(g~
m(g~g~
)=600
1χ∼
)=675,m(±1
χ∼
)=700,m(q~
m(q~q~
Multijet
Z+jets
W+jets
(+X) & single toptt
Diboson
Work in progressATLAS
SR - 4 jets
) [GeV]i
m(j40 60 80 100 120 140 160 180 200 220D
ATA/MC
00.51
1.52
2.5
mass of whichever jet in 4jet SRs
) [GeV]k,ji
m(j0 20 40 60 80 100 120 140 160 180 200 220
events
/6GeV
1
10
-1L dt=20.3 fb∫
=8TeV)sData 2012 (
SM Total
)=600
1χ∼
)=1150,m(±
1χ∼
)=1200,m(g~
m(g~
g~
)=600
1χ∼
)=675,m(±
1χ∼
)=700,m(q~
m(q~
q~
Multijet
Z+jets
W+jets
(+X) &single toptt
Diboson
Work in progressATLAS
SR - 4 jets
) [GeV]k,ji
m(j0 20 40 60 80 100 120 140 160 180 200 220D
ATA/MC
00.51
1.52
2.5
mass of remaining di-jet combination, 1unresolved W required, 4jet SRs
)jets
(Neff
/mmiss
TE
0 0.2 0.4 0.6 0.8 1 1.2
events/0.04
1
10
210
310-1
L dt = 20.3 fb∫= 8 TeV)sData 2012 (
SM Total
)=600
1χ∼
)=675,m(±1
χ∼
)=700,m(q~
m(q~q~
Multijet
Z+jets
W+jets
(+X) & single toptt
Diboson
Work in progressATLAS
SR - 4 jets (W)
4jW
)jets
(Neff
/mmiss
TE0 0.2 0.4 0.6 0.8 1 1.2D
ATA/MC
00.51
1.52
2.5
E missT /meff distribution for 4jW region
(incl.) [GeV]effm0 500 1000 1500 2000 2500 3000 3500 4000
events/100GeV
1
10-1
L dt=20.3 fb∫=8TeV)sData 2012 (
SM Total
)=600
1χ∼
)=675,m(±
1χ∼
)=700,m(q~
m(q~q~
Multijet
Z+jets
W+jets
(+X) &single toptt
Diboson
Work in progressATLAS
SR - 4 jets (W)
4jW
(incl.) [GeV]effm0 500 1000 1500 2000 2500 3000 3500 4000D
ATA/MC
00.51
1.52
2.5
meff distribution for 4jW region
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 10 / 18
Statistical treatmentMain background: Z,W+jets, Top, QCD, Diboson
Control regions (CR): CRY, CRQ, CRW, CRT
Signal regions (SR):
NSRexp = NCR
obsNSR
raw
NCRraw
transfer factornormalized through all CRs via likelihood fit
Likelihood: L(n|µ,s,b,θ) = PSR · PCRY · PCRQ · PCRT · PCRW · Csyst
CR SR Background CR process CR selection
CRY Z (→ νν)+jets γ+jets Isolated photon
CRQ Multijets MultijetsReversed ∆φ(ji ,E
missT ) and E miss
T /√
HT
or E missT /mmeff(Nj) cuts
CRW W (→ `ν)+jets W (→ `ν)+jets 30 GeV < mT (`,E missT ) < 100 GeV, b-veto
CRT tt̄ and single-t tt̄ → bbqq′`ν 30 GeV < mT (`,E missT ) < 100 GeV, b-tag
ATLAS Work in progress
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 11 / 18
Expected exclusion limits for one-step simplified models,m(LSP) = 60[GeV]
squark mass [GeV]
200 400 600 800 1000 1200
,LS
P)
q~m
(∆
,LS
P)/
± χm
(∆
x=
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1
0χ∼
1
0χ∼
W
+ Wq q→
1
χ∼
1
+χ∼ q q→* q~q~Simplified model,
ATLAS
=8 TeVs, 1
L dt = 20.3 fb∫Work in progress
0lepton combinedm(LSP)=60[GeV]
, 7 TeV)1
Observed limit (4.7 fb
)expσ1 ±Expected limit (
2jW
3jW
5j
6jt+
2jt
6jt+
6jl
5j
3jW
6jl
6jl
4jl
3jW
5j
6jt+
2jt
2jW
6jl5j
4jl
2jW
6jt+
4jt
6jt+
6jt+
4jl
4jt
6jt+
4jl
4jt
3j
4jt
6jt+
4jl
5j
6jt+
6jt+
6jt
5j
4jl 3j
2jW
6jt+
6jt+5j
3jW2jW
2jW
5j
2jt6jt+
4jl
4jl
4jl
6jt+
5j
5j
2jW
4jt
5j
4jt
5j
5j
2jW
3jW
5j
4jl
5j
4jt
6jl
6jt+
5j
3jW
6jl
5j
4jl
6jt+
4jt
6jt+
5j
3jW
3jW
5j
2jW
6jl
5j
4jl2jW
4jl
4jt
6jt+5j
4jt
2jW
2jm
6jt+
4jl
2jW
4jl
4jl
4jt2jl
6jt+
5j
6jt
4jl
5j
4jt
6jt+
6jt+
4jl
5j
5j
6jl
4jt
5j
6jt+
6jl
4jl
6jl
5j
4jl
squark→chargino→LSP,m(LSP) =60[GeV]
gluino mass [GeV]
200 400 600 800 1000 1200 1400 1600
,LS
P)
g~m
(∆
,LS
P)/
± χm
(∆
x=
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1
0χ∼
1
0χ∼ ±
W±
Wqqq q→ 1
±χ∼1
±χ∼ qqq q→ g~g~Simplified model,
ATLAS
=8 TeVs, 1
L dt = 20.3 fb∫Work in progress
0lepton combinedm(LSP)=60[GeV]
, 7 TeV)1
Observed limit (4.7 fb
)expσ1 ±Expected limit (
3jW
3jW
2jW
5j
6jt+
6jt+
4jt
6jl
6jl
6jt+
3jW 2jW
6jl
6jt+
2jW
6jl
3jW
6jt+
5j
6jt+
2jW
2jW
4jt
6jl6jm
4jl
2jW
6jt+
4jt
4jt
6jt
6jt+
6jt+
4jt
6jl
2jW
6jt+
6jt
6jt+
6jl
6jt+
6jt+
6jt+
6jt+
4jl
6jl
6jt+
6jl6jt+
6jl
6jt+
6jt+
6jt+
6jt+
5j
6jm
5j
6jl
6jt+
2jW3jW2jW
2jW
6jt+
6jt+
6jt+
2jW
6jt+
4jl
6jm
6jl
4jl
5j
3jW
6jt+
2jW
6jt+
6jl
2jW
6jt+
6jl
6jt+
6jt+
6jl5j
6jt+
3jW
6jt+
6jt+
3jW
6jt+
4jl
6jl
6jt
6jt+
4jt
5j
6jt+
6jt+
5j
6jt+
6jt+
2jW4jl
6jt+
6jt+
6jt+
6jt+
6jl
6jm
2jW4jl
2jW
6jt+
6jt
3jW
2jW
3jW
3jW
6jt+
6jt+
2jW
6jt+
6jt+
2jW
6jl
3jW
6jt
6jt+
6jl
6jl
6jt+
2jW
4jl
6jt+
4jm
6jt+
4jl
3jW
4jm
5j
6jt6jl
6jt+
5j
6jt
6jl
6jl
6jl
6jt+
6jt+
6jt+
2jW
3jW
5j
4jl
6jl
5j
4jt
6jt+
6jl
2jW
5j
4jl
6jl
6jl
6jt+
2jW
6jt+
gluino→chargino→LSP,m(LSP) =60[GeV]
Older results with 3jW. Boosted SRs improve exlusion limit for
x ≡ ∆(mg̃,LSP)∆(mχ̃−,LSP) ∼ 1!
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 12 / 18
Ongoing studies
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 13 / 18
Motivation for implementation of MT 2 variable
M2T 2 def.
minp1+p2=MET
[max [M2T (W1, p1),M2
T (W2, p2)]]
g̃
g̃
χ̃±1
χ̃∓1
p
p
q q
χ̃01
W
χ̃01
W
MT 2 is designed toreconstruct mass ofparticle which is producedin pair and decays intoinvisible (ν, χ̃0)
in our case: target is toreconstruct mass ofintermediate gauginos:
χ̃− →W−χ̃0
χ̃02 → Hχ̃0
1
and use MT 2 to suppressthe background
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 14 / 18
MT 2 distribution in unres-res + unres-unres W channels
) [GeV]2W1(WTm20 200 400 600 800 1000
events/20GeV
1
10
210
-1L dt = 20.3 fb∫
= 8 TeV)sData 2012 (SM Total
700,690,60q~q~
700,460,60q~q~
800,790,60q~q~
1200,1190,60g~g~
MultijetZ+jetsγ+ jetsW+jetsttbar & single topDiboson
InternalATLAS
SR
) [GeV]2W1
(WT2
m0 200 400 600 800 1000D
ATA/MC
00.51
1.52
2.5
) [GeV]2W1(WTm20 200 400 600 800 1000
events/20GeV
1
10
-1L dt = 20.3 fb∫
= 8 TeV)sData 2012 (SM Total
700,690,60q~q~
700,460,60q~q~
800,790,60q~q~
1200,1190,60g~g~
MultijetZ+jetsγ+ jetsW+jetsttbar & single topDiboson
InternalATLAS
SR
) [GeV]2W1
(WT2m0 200 400 600 800 1000D
ATA/MC
00.51
1.52
2.5
Selection:
all preselection 0-letpton cutsusedpT (j1) >130GeV,pT (j2) >60GeV, E miss
T >160GeVqcd redc.: ∆(φ)(j1,2,3) >0.4E miss
T /meff >0.3 (only bottomfig.)
Interesting:
see gg-1step point (niceseparation from background)MT 2 > 500. suppress QCDsee effect of E miss
T /meff >0.3(bottom figure on the left)
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 15 / 18
Correlation between meff and MT 2
410
310
210
effm
0 500 1000 1500 2000 2500 3000
T2
M
0
200
400
600
800
1000
sig_meff_mt2_corrsig_meff_mt2_corr
gg-onestep mg̃ = 1200,mχ̃+ =1190,mlsp = 60[GeV]
1
10
210
effm
0 500 1000 1500 2000 2500 3000
T2
M
0
200
400
600
800
1000
allbgallbg
Sum of all SM backgrounds,
MT 2 > 300?
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 16 / 18
Significance, combination of cuts
meff : meff >1500[GeV]E miss
T /meff : E missT /meff >0.3
MT 2: MT 2 >500[GeV]
meff meff ,MT 2 E missT /meff E miss
T /meff ,MT 2 E missT /meff ,meff E miss
T /meff ,meff ,MT 2
allbg 21770 149.2 546.5 70.3 36.1 12.4q̃q̃ 14.3 8.2 16 11.3 8.1 7.0g̃ g̃ 14 10.5 10.5 10.1 9.9 9.3s/√
b + s(q̃q̃) 0 0.7 0.7 1.3 1.2 1.6s/√
b + s(g̃ g̃) 0 0.8 0.5 1.1 1.5 2.0
Impact of combination of cuts on significance.g̃ g̃ -1step: m(gl) = 1200,m(char) = 1190,m(lsp) = 60.q̃q̃-1step: m(sq) = 800,m(char) = 790,m(lsp) = 60.At least 1 unresolved and 1 resolved W or 2 unresolved W required. Selection same as onprevious slides.
Best significancies achieved when combining all three cuts.
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 17 / 18
Conclusions&Plans
Conclusions:
boosted W regions have been developeddata/MC ratio is fairly close to one for all distributions in SRs and CRssuch new SRs improve expected exclusion limits
Plans:
finishing 0-lepton paper and work on pMSSM paperpreparing boosted 0-lepton analysis for 14 TeVstudying possibility of using shape fits on W mass peakstudying jet substructure and MT 2
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 18 / 18
back-up
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 1 / 4
SUSY analysis using some boosted technique
0-lepton: ATL-COM-PHYS-2013-1224
0-lepton stop: ATL-COM-PHYS-2013-1092
1-lepton stop: ATL-COM-PHYS-2013-1490 (boosted top tagging,AntiKt10 Jets)
boosted 3jet RPV: ATL-COM-PHYS-2012-793 (7TeV, 8TeV inprogress)
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 2 / 4
meff distribution in unres-res + unres-unres W channels
GeV0 500 1000 1500 2000 2500 3000 3500 4000
events
/ 1
00
1
10
210
1L dt = 20.3 fb∫
= 8 TeV)sData 2012 (SM Total
700,690,60q~
q~
700,460,60q~
q~
800,790,60q~
q~
1200,1190,60g~
g~
MultijetZ+jetsγ + jetsW+jetsttbar & single topDiboson
InternalATLAS
SR
GeV
0 500 1000 1500 2000 2500 3000 3500 4000DA
TA
/ M
C
00.5
11.5
22.5
meff distribution before E missT /meff
cut with same selection as on
previous slides
GeV0 500 1000 1500 2000 2500 3000 3500 4000
events
/ 1
00
1
10
1L dt = 20.3 fb∫
= 8 TeV)sData 2012 (SM Total
700,690,60q~
q~
700,460,60q~
q~
800,790,60q~
q~
1200,1190,60g~
g~
MultijetZ+jetsγ + jetsW+jetsttbar & single topDiboson
InternalATLAS
SR
GeV
0 500 1000 1500 2000 2500 3000 3500 4000DA
TA
/ M
C
00.5
11.5
22.5
E missT /meff > 0.3, meff is
unfortunately as powerful as MT 2,
but their combination could give
improvement!
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 3 / 4
Correlation between MET/meff and MT 2
-310
-210
-110
effm
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
T2
M
0
200
400
600
800
1000
sig_metmeff_mt2_corrsig_metmeff_mt2_corr
MET/
gg-onestep mg̃ = 1200,mχ̃+ =1190,mlsp = 60[GeV]
1
10
210
310
effMET/m
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
T2
M
0
200
400
600
800
1000
allbgallbg
Sum of all background, MT 2 > 300?
Tomas Javurek (UNI Freiburg) Boosted techniques in SUSY 30th April 2014 4 / 4