Supersymmetric particle searches at the Large … · Supersymmetric particle searches at the Large Hadron Collider Aleandro Nisati (INFN-Roma) XVI Frascati Spring School Frascati

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


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


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;

• 


theLHC 6

Thenewcoloredpar.clesareproducedwithahighratebythestrongforce


•  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


theLHC 8

SUSY particle production at the LHC


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)


•  Production cross section of SUSY particles –  NLO

corrections in pQCD are known


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)


theLHC 11



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.


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


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


theLHC 15

If we found an excess, is it SUSY?


theLHC 16

If we found an excess, is it SUSY?


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


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


theLHC 20

0-jet + Etmiss: control of backgrounds


theLHC 21

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SM Total

QCD multijet

W+jets

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and single topttSM + SU(660,240,0,10)

-1L dt = 1.04 fb!

Dijet Channel

ATLAS

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Z+jets


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Dijet Channel

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m0 500 1000 1500 2000 2500 3000

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Dijet Channel

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[GeV] eff

m0 500 1000 1500 2000 2500 3000

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C

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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


theLHC 22

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Dijet Channel

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Channel

ATLAS

[GeV] eff

m0 500 1000 1500 2000 2500 3000

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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


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



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



!1 !Expected limit

ATLAS EPS 2011



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



%1 "Expected limit

Reference point

2010 data PCL 95% C.L. limit

SUSY with Jets and ETmiss: CMS


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


theLHC 27

3JW+jetsCR 4JtopCR

Backgroundisevaluatedusingdataincontrolregions

1isolatedlepton+jets+ETmiss

SUSY: searches in lepton+jets+ETmiss


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


theLHC 29


•  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


theLHC 30


•  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


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

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trie

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.0

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4

6

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10

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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


theLHC 32

SUSY: sbottom searches

•  Gluino masses below 0.72 TeV for sbottom masses of below ~ 0.6 TeV are excluded


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

SUSY: sbottom searches


theLHC 34

Summary of R-parity conserving SUSY searches in CMS


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


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


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 •  …..


theLHC 38

perspectives


theLHC 39

√s=14TeVAnalyseotherSUSYScenarioExample:“compressedSUSY”

SerachforEWKproduc1onofgauginos

Searchfordirectsbocomandstopproduc1on

Gotohigherppcollisionenergies

SUSY Summary


theLHC 40

Mass scale [TeV]

-110 1 10

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on

g-liv

ed

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rtic

les

DG

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ird

ge

ne

ratio

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ea

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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

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(m mass ("

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=2.1 fbL

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(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

Backup


theLHC 41


•  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 –  …


theLHC 42

Thenewcoloredpar.clesareproducedwithahighratebythestrongforce

Documents

Supersymmetric particle searches at the Large … · Supersymmetric particle searches at the Large Hadron Collider Aleandro Nisati (INFN-Roma) XVI Frascati Spring School Frascati