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Supersymmetric particle searches at the Large Hadron Collider
Aleandro Nisati (INFN-Roma) XVI Frascati Spring School
Frascati 7-9 May, 2012
index
• Introduction • SUSY particle production • SUSY searches in the jets + ET
miss channel • SUSY seraches in the lepton+jets+Et
miss and dilepton channels
• Sbottom ans stop searches
May9th,2012 2A.Nisa1,thefirsttwoyearsofphysicsat
theLHC
The Hierarchy problem - 1
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 3
• The question: why the weak force is ~ 1032 times stronger than the gravitational force? – F ~ 1/[M2
Plr2]; MPl = 1.22×1019 GeV MH~102 GeV • Both forces involve constants of nature:
– The Fermi’s constant – The Newton’s constant
• In the Standard Model the quantum corrections to the Fermi constant appear unnaturally large, unless a delicate cancellation between the bare value of this constant and its quantum corrections take place (fine-tuning)
– More technically the question is why the Higgs boson mass is so much lighter than the Planck mass (or the Grand Unification energy)
The Hierarchy problem - 2
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 4
• Three main avenues for solving the hierarchy problem:
• Supersimmetry – A set of new (light) SUSY
particles cancel the divergence • Extra dimensions – There is a cut-off at the ~TeV scale where gravity sets
in; in other words the “actual” gravity constant is larger then the one observed (or the Planck mass is much smaller)
• Strong interactions/compositness – The Higgs is not an elementary scalar particle – The Higgs emerges as a Nambu-Goldostone boson of a
strongly interacting sector
Supersymmetry • Supersymmetry provides
a natural mechanism to keep small quantum corrections to the Higgs boson mass
• Supersymmetry provides a natural candidate for dark matter (the lightest supersymmetric particle)
• Supersymmetry facilitates the grand-unification of the em, weak and strong couplings
• Supersymmetry is an “extension” of the SM, it is consistent with the observed data
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 5
Δm=f(m2B-m2
F)
The Minimal SuperSymmetric Model (MSSM)
• More than 100 parameters to define the MSSM
• Enlarged Higgs sector: in the MSSM model there are two Higgs doublets, with five physical mass states: – h0, H0, neutral CP even; – A, neutral, CP odd – H+, H− charged;
•
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 6
Thenewcoloredpar.clesareproducedwithahighratebythestrongforce
The Minimal SuperSymmetric Model (MSSM)
• There are also Neutralinos and Charginos: – the neutral Wino and Bino,
and the neutral Higgsinos mix to the 4 neutralinos
– the charged Wino fields and the charged Higgsino fields mix to the 4 charginos
• If R-parity is conserved the lightest neutralino is stable, weakly interacting and massive ideal Dark Matter candidate May9th,2012
A.Nisa1,thefirsttwoyearsofphysicsattheLHC 7
PR=(‐1)2s+3B+L,where:SisthespinBisthebaryonnumberListheleptonnumber
AllStandardModelpar1cleshaveR‐parityof1whilesupersymmetricpar1cleshaveR‐parity‐1.
mSUGRA/cMSSM • Specific models with less parameters: – mSUGRA/cMSSM – GMSB – AMSB – …
• Most studied scenario is the 5 parameter mSUGRA model – m0: common boson mass at GUT scale; – m1/2 common fermion mass at GUT scale – tanβ: ratio of higgs vacuum expectation values – A0: common GUT trilinear coupling – µ: sign of Higgs potential
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 8
SUSY particle production at the LHC
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 9
Initial state: gg, qq, qg Final state: squarks and gluinos via strong interaction (αs); this is the dominant SUSY particle production
Drell-Yan production of sleptons, charginos and neutralinos (lower cross sections)
SUSY particle production at the LHC
• Production cross section of SUSY particles – NLO
corrections in pQCD are known
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 10
SUSY particle production at the LHC • Decays of heavy
SUSY particles long and complex decay chains
• Invariants in R-parity conserving SUSY: jets, (large) ET
miss (2 LSPs)
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 11
SUSY particle production at the LHC
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 12
• Shorter decay chains for chargino/neutralino direct production
Baseline SUSY searches at the LHC
• Squarks and gluinos are strongly produced
• They decay through a particle cascade that includes high pT jets and high pT LSPs, (i.e. large Et
miss)
• Strategy for searching for SUSY particles at the LHC: – Select events with final
state produced by SUSY cascades. Example: Multijet + large Et
miss signature
– Define inclusive variable(s) sensitive to SUSY at different mass scales, e.g. effective mass Meff ;
– Study the distribution of this(these) variable(s) in the Standard Model and look for deviations from the predictions of this theory.
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 13
A typical search for squarks and gluinos
• If R-parity conserved, cascade decays produce distinctive events: multiple jets, leptons, and large Et
miss
• Typical selection: – At least 4 high pT jets,
satisfying the thresholds 100, 50, 50, 50 GeV;
– no lepton with pT > 20 GeV – ET
miss > 100 GeV; – Meff = Σ pT(jets) + ET
miss
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 14
simula1on
• Example: example: mSUGRA, point SU3 (bulk region) – m0 = 100 GeV, – m1/2 = 300 GeV, – tan β = 6, – A0 = -300 GeV, – µ > 0
Strategy for SUSY searches at the LHC
• Search for excesses in multijet + no-lepton + missing transverse energy events
• Search for excesses in single lepton, opposite sign dilepton, same sign dilepton, taus, in association with jets and missing transverse energy
• Look for special features (γ’s, long lived sleptons)
• End-point analyses, global fit SUSY model parameters
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 15
If we found an excess, is it SUSY?
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 17
OtherpossiblescenariosforPhysicsBeyondtheStandardModelcouldleadtosimilarfinalstatesignatures
Some useful quantities used in SUSY analyses Quan.ty Defini.on
mT transverse mass (in general: mT lepton, pTmiss))
ETmiss missing transverse energy, (measured from the
energy depositions in the calorimeters and from muons)
Meff effective mass, scalar sum of transverse energies of selected high pT objects, and Et
miss (including leptons if selected in the analysis)
HT scalar sum of total transverse energy in selected jets (hadronic activity)
HTmiss Magnitude of vector sum of selected jet
αT In two-jet events, αT=ETj2/MT, where ET
j2 is the transverse energy of the less energetic jet, and MT is the transverse mass of the dijet system
Δφ(jet; pT
miss) angle between the missing transverse energy vector and a jet in the transverse plane important to reject “fake” background from QCD jet production May9th,2012
A.Nisa1,thefirsttwoyearsofphysicsattheLHC 18
Search in the jets + ETmiss channel
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 19
• Based on L=1.04 fb-1 of data • Selection of events with high-pT jets and large ET
miss • Split the analysis according to jet multiplicities:
– ≥2, ≥3, and ≥4 jets • this optimize sensitivity to squark/gluino mass combination, i.e. to
different regions of the SUSY phase space Five signal regions
Search in the jets + ETmiss channel
• Three different type of analysed are performed, depending on the squark gluino mass: – Dijet analysis – Trijet analysis – Four jet (gluino) analysis
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 20
0-jet + Etmiss: control of backgrounds
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 21
En
trie
s /
10
0 G
eV
-110
1
10
210
310
410
510 = 7 TeV)sData 2011 (
SM Total
QCD multijet
W+jets
Z+jets
and single topttSM + SU(660,240,0,10)
-1L dt = 1.04 fb!
Dijet Channel
ATLAS
[GeV] eff
m0 500 1000 1500 2000 2500 3000
DA
TA
/ M
C
00.5
11.5
22.5
En
trie
s /
10
0 G
eV
-110
1
10
210
310
410
510
610
710 = 7 TeV)sData 2011 (
SM Total
QCD multijet
W+jets
Z+jets
and single topttSM + SU(660,240,0,10)
-1L dt = 1.04 fb!
Dijet Channel
ATLAS
[GeV] eff
m0 500 1000 1500 2000 2500 3000
DA
TA
/ M
C
00.5
11.5
22.5
En
trie
s /
10
0 G
eV
1
10
210
310
410
510
= 7 TeV)sData 2011 (
SM Total
QCD multijet
W+jets
Z+jets
and single topttSM + SU(660,240,0,10)
-1L dt = 1.04 fb!
Dijet Channel
ATLAS
[GeV] eff
m0 500 1000 1500 2000 2500 3000
DA
TA
/ M
C
00.5
11.5
22.5
En
trie
s /
10
0 G
eV
1
10
210
310
410
510 = 7 TeV)sData 2011 (
SM Total
QCD multijet
W+jets
Z+jets
and single topttSM + SU(660,240,0,10)
-1L dt = 1.04 fb!
Dijet Channel
ATLAS
[GeV] eff
m0 500 1000 1500 2000 2500 3000
DA
TA
/ M
C
00.5
11.5
22.5
• 5 “control regions” per each of the 5 signal regions
• Extrapolate the observations from the control regions to the signal regions with “transfer factors” – obtained with a combination of data
and MC inputs.
A
C
B
D
A estimate Zνν+jets: use Zll+jets events (transfer the lepton pair momentum to Et
miss); plot: no ET
miss and meff cuts are applied
B estimate multi-jet: revert Δϕ(jet; Et
miss)min<0.2 C estimate Wlν+jets: select
events with one lepton+Etmiss
with 30<mT<100 GeV, and b-jet veto; threat the lepton as a jet;
D estimate top quark back.: as for Wlν+jets, but require at least one b-tagged jet
0-jet + ETmiss: Results
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 22
En
trie
s /
10
0 G
eV
1
10
210
310
410
510
610 = 7 TeV)sData 2011 (
SM Total
QCD multijet
W+jets
Z+jets
and single topttSM + SU(660,240,0,10)
-1L dt = 1.04 fb!
Dijet Channel
ATLAS
[GeV] eff
m0 500 1000 1500 2000 2500 3000
DA
TA
/ M
C
00.5
11.5
22.5
En
trie
s /
10
0 G
eV
1
10
210
310
410
510
= 7 TeV)sData 2011 (
SM Total
QCD multijet
W+jets
Z+jets
and single topttSM + SU(660,240,0,10)
-1L dt = 1.04 fb!
Three Jet Channel
ATLAS
[GeV] eff
m0 500 1000 1500 2000 2500 3000
DA
TA
/ M
C
00.5
11.5
22.5
En
trie
s /
15
0 G
eV
-110
1
10
210
310
410
510 = 7 TeV)sData 2011 (
SM Total
QCD multijet
W+jets
Z+jets
and single topttSM + SU(660,240,0,10)
-1L dt = 1.04 fb!
Four Jet High Mass
Channel
ATLAS
[GeV] eff
m0 500 1000 1500 2000 2500 3000
DA
TA
/ M
C
00.5
11.5
22.5
Fitted background in each SR, compared with the number of the observed events in data. Systematic uncertainties are taken into account
The observed meff distribution in the various signal regions considered in the analysis
εσAlimit(?):22254292717
Interpretation: simplified SUSY Model
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 23gluino mass [GeV]0 250 500 750 1000 1250 1500 1750 2000
squark
mass [G
eV
]
0
250
500
750
1000
1250
1500
1750
2000
q~
LEP2
Tevatr
on, R
un I
CD
F, R
un II
D0, R
un II
= 10 pbSUSY!
= 1 pbSUSY
!
= 0.1 pbSUSY!
= 0.01 pbSUSY!
) = 0 GeV1
0"#Squark-gluino-neutralino model, m(
=7 TeVs, -1
L dt = 1.04 fb$
0 lepton 2011 combined
ATLAS
observed 95% C.L. limitsCL
median expected limitsCL
!1 !Expected limit
2010 data PCL 95% C.L. limit
Squarkandgluinowithmassbelow0.875TeVand0.700TeVrespec.velyforgluinoandsquarkwithmassbelow2TeV,areexcludedat95%C.L.
• mX = 0 • Masses of gluinos and
squarks of 1st and 2nd generation as given on plot
• All other SUSY masses are decoupled, by being given masses of 5 TeV
Interpretation: simplified SUSY Model
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 24
• mX = 0 • Masses of gluinos and
squarks of 1st and 2nd generation as given on plot
• All other SUSY masses are decoupled, by being given masses of 5 TeV
gluino mass [GeV]600 800 1000 1200 1400 1600 1800 2000
squark
mass [G
eV
]
600
800
1000
1200
1400
1600
1800
2000
= 100 fbSUSY!
= 10 fbSUSY!
= 1 fbSUSY!
) = 0 GeV1
0"#Squark-gluino-neutralino model, m(
=7 TeVs, -1
L dt = 4.71 fb$
Combined
PreliminaryATLAS
observed 95% C.L. limitsCL
median expected limitsCL
!1 !Expected limit
ATLAS EPS 2011
Interpretation: simplified SUSY Model
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 25
• tanβ = 0 • A0=0 • µ>0
Squark and gluino with mass below ~ 1 TeV are excluded at 95% C.L.
[GeV]0m500 1000 1500 2000 2500 3000 3500
[G
eV
]1/2
m
200
300
400
500
600
(600)g~
(800)g~
(1000)g~
(1200)g~
(600)
q~
(1000)
q ~
(1400)
q ~
>0!= 0, 0
= 10, A!MSUGRA/CMSSM: tan
=7 TeVs, -1
L dt = 1.04 fb"
0 lepton 2011 combinedATLAS 0 lepton 2011 combined
1
" #$LEP2
-1<0, 2.1 fb!=3, !, tan q~, g~D0 -1<0, 2 fb!=5, !, tan q~,g~CDF
Theoretically excluded
observed 95% C.L. limitsCL
median expected limitsCL
%1 "Expected limit
Reference point
2010 data PCL 95% C.L. limit
SUSY with Jets and ETmiss: CMS
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 26
(GeV)0
m0 500 1000 1500 2000
(G
eV
)1
/2m
200
400
600
(500)GeV
q~
(750)GeV
q~
(1000)GeV
q~
(1250)GeV
q~
(1500)GeVq~
(500)GeVg~
(750)GeVg~
(1000)GeVg~
(1250)GeVg~
(1500)GeVg~
= 7 TeVs, -1CMS, 1.14 fb
> 0µ = 0 GeV, 0
= 10, A!tan
LM6
= L
SP
"#95% CL limits:
sObserved Limit (NLO), CL
$ 1 ±Median Expected Limit
(GeV)0
m0 500 1000 1500 2000
(G
eV
)1
/2m
200
400
600
(GeV)0
m0 500 1000 1500 2000
(G
eV
)1
/2m
200
400
600
CMSexclusionlimitsinthecMSSMmodelSimilarexclusionasfromtheATLASexperimentSquarkandgluinoswithmasscanbeexcludedat95%CLform0<500GeV
SUSY: searches in lepton+jets+ETmiss
• Dominant background: – W(Z)+jets – Ttbar – Multijet contamination is negligible
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 27
3JW+jetsCR 4JtopCR
Backgroundisevaluatedusingdataincontrolregions
1isolatedlepton+jets+ETmiss
SUSY: searches in lepton+jets+ETmiss
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 28
εσAlimits(?)e:50143310μ:3610319
SUSY: ETmiss + 2 leptons
• dilepton final states can be produced by cascade decays yielding flavour correlated lepton pairs
• Like-sign dilepton production appears in many models of Physics Beyond the Standard Model, including SUSY
• Backgrounds from Standard Model are in general small. Main contributions from: – Diboson (WZ) – ttbar production (where one lepton
comes from the semileptonic b-decay)
– Fake leptons • Lepton pt values in SUSY cascade
might be low, depending on the mass difference of the SUSY particles involved search for low pt lepton as possible
• Taus (3rd generation) may play an important role, stau could the lightest slepton
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 29
SUSY: ETmiss + 2 leptons
• An example: search for a characteristic edge in the opposite-sign dilepton mass spectra
• CMS: event preselection: similar to the one of made for ttbar cross section measurement in the dilepton channel: – Two opposite-sign isolated
high-pT leptons – At least two high-pT jets – Large Et
miss
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 30
SUSY: ETmiss + 2 leptons
• Signal region: select events with HT>300 GeV, Etmiss > 100 GeV – ee,µµ events (left) and eµ
events (right)
• No evidence for a characteristic di-lepton edge in the data
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 31
[GeV]llm0 50 100 150 200 250 300
Entr
ies / 1
0.0
0
2
4
6
8
10
12
14
16
CMS preliminary-1 = 7 TeV, 0.98 fbs
7.7± = 8.4 Sn
9.0± = 81.5 Bn
3.2± = 1.0 Zn
Data
FitSignal
!/0
Z-shapeµe
Uncertainty
[GeV]µem0 50 100 150 200 250 300
En
trie
s /
10
.0
0
2
4
6
8
10
12
14
CMS preliminary-1 = 7 TeV, 0.98 fbs
Data
-shapeµe
Uncertainty
SUSY: sbottom and stop searches
• In the MSSM the scalar partners of right-handed and left-handed quarks, sqR and sqL, can mix to form two mass eigenstates
• The mixing is proportional to the mass of the corresponding SM fermions, and therefore it becomes important for the 3rd generation
• Large mixing can yeld sbottom and stop with mass eigenstates which are signficantly lighter than other squarks
• stop and sbottom could be produced with large cross sections at the LHC
• b-quarks appear in their decays
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 32
SUSY: sbottom searches
• Gluino masses below 0.72 TeV for sbottom masses of below ~ 0.6 TeV are excluded
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 33
[GeV]g~
m100 200 300 400 500 600 700 800 900 1000
[G
eV
]1
b~m
200
300
400
500
600
700
800
900
1000
0
1!" b+#
1b~
production, 1
b~
-1
b~
+ g~-g~ =7 TeVs, -1
L dt = 0.83 fb$
b-jet analyses
0 lepton, 3 jets
PreliminaryATLAS
0 lepton, 3 jets
Reference point
)g~)>>m(1,2
q~) = 60 GeV, m(0
1!"m(
b forb
idden
b~#g~
observed limits
CL expected limit
sCL68% and 99% C.L.
expected limitss
CL)-1ATLAS (35 pb
-1 2.65 fb1
b~
1b~
CDF
-1 5.2 fb1
b~
1b~
D0
-1b 2.5 fb1
b~ #, g~g~CDF
Events
/ 50 G
eV
-110
1
10
210
310
410
5100-lepton,3 jets
>= 1 bjet
Data 2011
SM Totaltop production
W production
Z production
QCD production
380 GeVb~
700 GeV, g~
= 7 TeVs, -1
L dt = 0.83 fb!ATLAS Preliminary
[GeV]effm
0 200 400 600 800 1000 1200 1400
da
ta /
MC
00.5
11.5
22.5
Eventswith1b‐taggedjet
Exclusionlimitsinthe(msbocom‐mgluino)plane,thatthelightestsquark(sbocom1)isproducedviagluinogluinomediatedproduc1on,ordirectpairproduc1on,assuming100%BRsb1bX10
Summary of R-parity conserving SUSY searches in CMS
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 35)2 (GeV/c0
m
0 200 400 600 800 1000
)2
(G
eV
/c1/2
m
200
300
400
500
600
700
(250)GeV
q~
(250)GeVg~
(500)GeV
q~
(500)GeVg~
(750)GeVq~
(750)GeVg~
(1000)GeVq~
(1000)GeVg~
(1250)GeVq~
(1250)GeVg~
T!
Jets+MHT
)-1
Razor (0.8 fb
SS Dilepton
OS Dilepton
Multi-Lepton)
-1(2.1 fb
MT2
1 Lepton
-1 1 fb" = 7 TeV, Ldt s #CMS Preliminary
> 0µ = 0, 0
= 10, A$tan
<0µ=5, $tan, q~, g~CDF
<0µ=3, $tan, q~, g~D0
±
1%&LEP2
±l~
LEP2
= L
SP
'&
2011 Limits
2010 Limits
Summary of R-parity conserving SUSY searches in CMS
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 36)2 (GeV/c0
m
0 200 400 600 800 1000
)2
(G
eV
/c1/2
m
200
300
400
500
600
700
(250)GeV
q~
(250)GeVg~
(500)GeV
q~
(500)GeVg~
(750)GeVq~
(750)GeVg~
(1000)GeVq~
(1000)GeVg~
(1250)GeVq~
(1250)GeVg~
T!
Jets+MHT
)-1
Razor (0.8 fb
SS Dilepton
OS Dilepton
Multi-Lepton)
-1(2.1 fb
MT2
1 Lepton
-1 1 fb" = 7 TeV, Ldt s #CMS Preliminary
> 0µ = 0, 0
= 10, A$tan
<0µ=5, $tan, q~, g~CDF
<0µ=3, $tan, q~, g~D0
±
1%&LEP2
±l~
LEP2
= L
SP
'&
2011 Limits
2010 Limits
• ATLAS and CMS have analysed very efficiently their data • Results are available for an integrated luminosity of 1 fb-1
• So far, no evidence for R-parity SUSY particle production: no squark/gluinos with mass lighter than ~ 1 TeV
• Need to explore other SUSY scenarios
Search for Gauge Mediated SUSY breaking scenarios (GMSB)
• In Gauge mediated SUSY breaking models (GMSB), SUSY breaking occurs at energy scales much smaller than the Planck scale, breaking linked to gauge interactions
• The gravitino is the LSP, escaped detection ET
miss signature • Phenomenology is
determined by the NLSP (next-to-lightest SUSY particle).
In many scenarios the NLSP are the super-partners of the SU(2) gauge fields – Decay scenarios
– Also X01 can be the NSLP
with decay
– expect/search for events with photons, leptons, Etmiss
– In GMSB models, sleptons squarks, gluinos might have long lifetime
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 37
… and much more!
• Many other scenarios have been investigated • Not presented in these lectures • Final states with photons and Etmiss • Long liftime new particles • Heavily ionizing particles • R-parity violating models • Disappearing tracks • …..
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 38
perspectives
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 39
√s=14TeVAnalyseotherSUSYScenarioExample:“compressedSUSY”
SerachforEWKproduc1onofgauginos
Searchfordirectsbocomandstopproduc1on
Gotohigherppcollisionenergies
SUSY Summary
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 40
Mass scale [TeV]
-110 1 10
RP
VL
on
g-liv
ed
pa
rtic
les
DG
Th
ird
ge
ne
ratio
nIn
clu
siv
e s
ea
rch
es
klm !
ijmHypercolour scalar gluons : 4 jets,
,missTEMSUGRA/CMSSM - BC1 RPV : 4-lepton +
,missTEBilinear RPV : 1-lep + j’s +
!RPV : high-mass e
"#GMSB : stable
SMP : R-hadrons (Pixel det. only)
SMP : R-hadrons
SMP : R-hadrons
Stable massive particles (SMP) : R-hadrons
"
1$#AMSB : long-lived
,missTE) : 3-lep + 0
1$# 3l %
0
2$#"
1$#Direct gaugino (
,missTE) : 2-lep SS + 0
1$# 3l %
0
2$#"
1$#Direct gaugino (
,missTEll) + b-jet + % (GMSB) : Z(t
~t~
Direct ,missTE) : 2 b-jets +
0
1$# b%
1b~
(b~
b~
Direct
,missTE) : multi-j’s + 0
1$#tt%g~ (t
~Gluino med.
,missTE) : 2-lep (SS) + j’s + 0
1$#tt%g~ (t
~Gluino med.
,missTE) : 1-lep + b-j’s + 0
1$#tt%g~ (t
~Gluino med.
,missTE) : 0-lep + b-j’s + 0
1$#bb%g~ (b
~Gluino med.
,missTE + &&GGM :
,missTE + j’s + "GMSB : 2-
,missTE + j’s + "GMSB : 1-
,missTE + SF
GMSB : 2-lep OS,missTE) : 1-lep + j’s +
"$#q q%g~ (
"$#Gluino med.
,missTEPheno model : 0-lep + j’s +
,missTEPheno model : 0-lep + j’s +
,missTEMSUGRA/CMSSM : multijets +
,missTEMSUGRA/CMSSM : 1-lep + j’s +
,missTEMSUGRA/CMSSM : 0-lep + j’s +
3 GeV)" 140 ! sgm < 100 GeV, sgmsgluon mass (excl: 185 GeV (2010) [1110.2693]-1
=34 pbL
massg~
1.77 TeV (2011) [ATLAS-CONF-2012-035]-1
=2.1 fbL
< 15 mm)LSP" mass (cg
~ = q
~760 GeV (2011) [1109.6606]
-1=1.0 fbL
=0.05)312
'=0.10, ,
311' mass ("(
#1.32 TeV (2011) [1109.3089]
-1=1.1 fbL
mass"#136 GeV (2010) [1106.4495]-1
=37 pbL
massg~
810 GeV (2011) [ATLAS-CONF-2012-022]-1
=2.1 fbL
masst~
309 GeV (2010) [1103.1984]-1
=34 pbL
massb~
294 GeV (2010) [1103.1984]-1
=34 pbL
massg~
562 GeV (2010) [1103.1984]-1
=34 pbL
) < 2 ns, 90 GeV limit in [0.2,90] ns)"
1$#
(" mass (1 < "
1$#118 GeV
(2011) [CF-2012-034]-1
=4.7 fbL
) < 170 GeV, and as above)0
1$#
(m mass ("
1$#
250 GeV (2011) [ATLAS-CONF-2012-023]-1
=2.1 fbL
)))0
2$#
(m) + 0
1$#
(m(21) = (
#,l
~(m),
0
2$#
(m) = "
1$#
(m, 0
1$#
) < 40 GeV, 0
1$#
(m mass (("
1$#
170 GeV (2011) [1110.6189]-1
=1.0 fbL
) < 230 GeV)0
1$#
(m mass (115 < t~
310 GeV (2011) [ATLAS-CONF-2012-036]-1
=2.1 fbL
) < 60 GeV)0
1$#
(m mass (b~
390 GeV (2011) [1112.3832]-1
=2.1 fbL
) < 200 GeV)0
1$#
(m mass (g~
830 GeV (2011) [ATLAS-CONF-2012-037]-1
=4.7 fbL
) < 210 GeV)0
1$#
(m mass (g~
650 GeV (2011) [ATLAS-CONF-2012-004]-1
=2.1 fbL
) < 150 GeV)0
1$#
(m mass (g~
710 GeV (2011) [ATLAS-CONF-2012-003]-1
=2.1 fbL
) < 300 GeV)0
1$#
(m mass (g~
900 GeV (2011) [ATLAS-CONF-2012-003]-1
=2.1 fbL
) > 50 GeV)0
1$#
(m mass (g~
805 GeV (2011) [1111.4116]-1
=1.1 fbL
> 20)) mass (tang~
990 GeV (2011) [ATLAS-CONF-2012-002]-1
=2.1 fbL
> 20)) mass (tang~
920 GeV (2011) [ATLAS-CONF-2012-005]-1
=2.1 fbL
< 35)) mass (tang~
810 GeV (2011) [ATLAS-CONF-2011-156]-1
=1.0 fbL
))g~
(m)+0$#
(m(21) =
"$#
(m) < 200 GeV, 0
1$#
(m mass (g~
900 GeV (2011) [ATLAS-CONF-2012-041]-1
=4.7 fbL
)0
1$#
) < 2 TeV, light q~
(m mass (g~
940 GeV (2011) [ATLAS-CONF-2012-033]-1
=4.7 fbL
)0
1$#
) < 2 TeV, light g~
(m mass (q~
1.38 TeV (2011) [ATLAS-CONF-2012-033]-1
=4.7 fbL
)0m mass (large g~
850 GeV (2011) [ATLAS-CONF-2012-037]-1
=4.7 fbL
massg~
= q~
1.20 TeV (2011) [ATLAS-CONF-2012-041]-1
=4.7 fbL
massg~
= q~
1.40 TeV (2011) [ATLAS-CONF-2012-033]-1
=4.7 fbL
Only a selection of the available mass limits on new states or phenomena shown*
-1 = (0.03 - 4.7) fbLdt* = 7 TeVs
ATLASPreliminary
ATLAS SUSY Searches* - 95% CL Lower Limits (Status: March 2012) March2012
The Minimal SuperSymmetric Model (MSSM)
• More than 100 parameters to define the MSSM
• In the MSSM model there are five Higgs bosons: – h0, H0, neutral CP even; – A, neutral, CP odd – H+, H− charged;
• Specific models with less parameters: – mSUGRA/cMSSM – GMSB – AMSB – …
May9th,2012A.Nisa1,thefirsttwoyearsofphysicsat
theLHC 42
Thenewcoloredpar.clesareproducedwithahighratebythestrongforce