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From the TeVatron to the LHC: What could lie beyond the SM?. Monica D’Onofrio IFAE-Barcelona HEP Seminar, University of Oxford, 28 th October 2008. The Standard Model. Matter is made out of fermions: 3 generations of quarks and leptons Forces are carried by Bosons:

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from the tevatron to the lhc what could lie beyond the sm

From the TeVatron to the LHC: What could lie beyond the SM?

Monica D’Onofrio

IFAE-Barcelona

HEP Seminar, University of Oxford, 28th October 2008

the standard model
The Standard Model
  • Matter is made out of fermions:
    • 3 generations of quarks and leptons
  • Forces are carried by Bosons:
    • Electroweak: ,W,Z
    • Strong: gluons
  • Remarkably successful description of known phenomena:
    • predicted the existence of charm, bottom, top quarks, tau neutrino, W and Z bosons.
    • Very good fit to the experimental
    • data so far
  • but ...

University of Oxford, 10/28/2008

the missing piece the higgs
The missing piece: the Higgs
  • WOULD THE HIGGS DISCOVERY
    • COMPLETE OUR UNDERSTANDING OF NATURE ?

What is the origin of masses?

 Within SM, Higgs field gives mass to Particles (EWK symmetry breaking)

SM predicts existence of a new massive neutral particle

Not found yet!

Theory does not predict its mass

LEP limit: mH>114 GeV @ 95% CL

Indirect limit from EW data:

- Preferred value: mH = 84+34-26 GeV

- mH < 154 GeV @ 95% CL

with aS (MZ) = 0.1185±0.0026, DaS(5)had=0.02758±0.00035

University of Oxford, 10/28/2008

beyond sm the unknown
Beyond SM: the Unknown

The Standard Model is theoretically incomplete

  • Mass hierarchy problem
  •  radiative correction in Higgs sector
  • Unification
  • Dark Matter
  • Matter-antimatter asymmetry
  • Many possible new particles and theories
    • SuperSymmetry
    • Extra Dimension
    • New Gauge groups (Z’, W’)
    • New fermions (e*, t’, b’ …)

f

H

DmH2 ~ L2

L = Mpl ?

Can show up in direct searches or as subtle deviations in precision measurements

University of Oxford, 10/28/2008

outline
Outline
  • Tevatron and the CDF and D0 experiments
  • Tevatron sensitivities: achievements understanding the SM
  • The SM Higgs
  • Searching for physics beyond SM
    • Supersymmetry
      • mSUGRA-inspired searches:
        • Squark/gluino
        • Chargino/neutralinos
      • GMSB-inspired searches
        • Diphoton+X
        • Delayed photon analysis
      • MSSM Higgs
    • Extra-dimension and new gauge bosons:
      • Search for high-mass resonances
  • Perspectives for the LHC

University of Oxford, 10/28/2008

the tevatron

_

The Tevatron

p

p

CDF

Highest-energy accelerator

currently operational

D0

Peak luminosity > 3.2 *1032 cm-2 s-1

Integrated luminosity/week

 ~ 40-60 pb-1

Delivered: 5.1 fb-1

Acquired: 4.2-4.3 fb-1

(CDF/ DØ)

University of Oxford, 10/28/2008

cdf and d in runii
CDF and DØin RunII

CDF

D0

Took >1 years of collisions to

get to stable high efficiency

Oct 08

Jan 02

University of Oxford, 10/28/2008

tevatron sensitivities
Tevatron Sensitivities
  • Jet cross section measurements, heavy flavor physics, inclusive W/Z
  • Precision measurements (Top properties, observation of rare processes...)
  • New Physics searches, looking for ‘the’ unexpected

Both CDF and D0 have a very rich physics program!

University of Oxford, 10/28/2008

knowledge of the sm qcd and ewk
Knowledge of the SM: QCD and EWK
  • Z(e+e-)+jets
    • Clean signature, low background
    • Test ground for Monte Carlo tools
  • W Mass and width
  • MW = 80413±48 MeV
  • GW = 2032±73MeV
  • world’s most precise single measurements!

Test of Next-to-Leading Order

perturbative QCD

  • inclusive jet cross section
    • Probing distances ~10-19 m
    • Constrains gluon PDF at high-x

University of Oxford, 10/28/2008

knowledge of sm top physics
Knowledge of SM: top physics

Mtop = 172.4 ± 0.7 (stat) ± 1.0 (syst) GeV/c2

  • Top quark discovered at the Tevatron in 1995
  • Very extensive program on top physics:
    • Precision measurements of top mass
    • Top cross sections, properties…

University of Oxford, 10/28/2008

knowledge of sm rare processes
Knowledge of SM: rare processes
  • DiBoson cross sections

D0:s + t = 4.7 ± 1.3 pb

CDF: s + t = 2.0-2.7 pb (± 0.7 pbper analysis)

Measurements of W/Zg,

WW and WZcross sections

Consistent with NLO calculation

ZZ production  Evidence at CDF

Observation at D0!!

Consistent with NLO calculation: 1.4 ± 0.1 pb

The focus is now to uncover the unknown

University of Oxford, 10/28/2008

Evidence of Single top production

needle in the haystack
Needle in the haystack

 Model-inspired searches

  • Theory driven
  • Model-dependent optimization of event selection
  • Set limits on model parameters

 Signature-based searches

  • Signature driven
  • Optimize selection to reduce backgrounds
  • Event count; event kinematics

Every measurement we make is an attempt to find New Physics

When searching for a needle in a haystack, the hay is more important than the needle...

Many searches are extensions of SM measurements.

University of Oxford, 10/28/2008

sm higgs production and decay
SM Higgs Production and Decay
  • Direct production gg→H
    • Highest Production rate
    • Largest background
  • Associated production ZH/WH
    • Leptonic vector boson decay helps for triggering and signal extraction

MH (GeV/c2)

  • Low Mass (MH<135 GeV/c2)
    • H→bb mode dominates
    •  WHlbb, ZHbb , ZHllbb
    • VBF Production, VHqqbb, H(with
    • 2jets), H, WH->WWW, ttH
  • High Mass (135<MH<200 GeV/c2)
    • H→WW mode dominates

University of Oxford, 10/28/2008

higgs ww l l
Higgs→WW*→ll
  • Most sensitive channel for high mass Higgs
    • gg →H → WW* and W(Z)H → W(Z)WW*
  • Unbalanced transverse energy (MET) from n
  • 2 leptons: e,,→e, (must haveopposite signs)
    • Key issue: Maximizing lepton acceptance
    • Primary backgrounds: Drell-Yan, WW
      • Higgs is scalar  leptons travel same direction
      • In t-channel WW, W are polarized along the beam direction
  • Use Matrix Element and Neural Network methods

Results at mH = 165GeV : 95%CL Limits/SM

University of Oxford, 10/28/2008

sm higgs limits
SM Higgs limits

CDF/D0 combination: High mass only

Exp. 1.2 @ 165, 1.4 @ 170 GeV

Obs. 1.0 @ 170 GeV

Tevatron exclude at 95% C.L. the

production of a SM Higgs boson of 170 GeV

Low mass combination difficult due to ~70 channels: Expected sensitivity of CDF/DØ combined: <3.0xSM @ 115GeV

A 15 GeV window [162:177] excluded @ 90% CL

University of Oxford, 10/28/2008

searches beyond sm

Searches Beyond SM

Supersymmetry

supersymmetry
Supersymmetry
  • New spin-based symmetry relating

fermions and bosons:

Q|Boson> = Fermion

Q|Fermion> = Boson

gaugino/higgsino mixing

  • Minimal SuperSymmetric SM (MSSM):
    • Mirror spectrum of particles
    • Enlarged Higgs sector: two doublets with 5 physical states
  • Naturally solve the
  • hierarchy problem
  • Define R-parity = (-1)3(B-L)+2s
    • R = 1 for SM particles
    • R = -1 for MSSM partners

If conserved, provides

Dark Matter Candidate

(Lightest Supersymmetric Particle)

University of Oxford, 10/28/2008

symmetry breaking

gravity

SUSY breaking

(hidden sector)

MSSM

(visible sector)

or

Gauge fields, loop effects….

Symmetry breaking

No SUSY particles found yet:

  • SUSY must be broken
  • More than 100 parameters even in minimal (MSSM) models
  • Breaking mechanism determines phenomenologyand search strategy at colliders:
    • Direct searches or subtle deviations in precision measurements

mSUGRA,

GMSB,

….

choose a model 

Constrained MSSM models used as benchmark

University of Oxford, 10/28/2008

sparticles mass and cross sections
Sparticles mass and cross sections

1. Unified gaugino mass m1/2

2. Unified scalar mass m0

3. Ratio of H1, H2 vevs tanβ

4. Trilinear coupling A0

5. Higgs mass term sgn()

  • in mSUGRA, new superfields in “hidden” sector
  • Interact gravitationally with MSSM
  • 5 parameter at GUT scale

T. Plehn, PROSPINO

(pb)

m (GeV)

  • Squarks and gluinos are heavy
  • Sizeable Chargino/neutralino cross sections

M(+) ~ M(02) ~ 2M(01)

M(g) ~ 3M(+)

In R parity conservation scenario,

the LSP is the neutralino (c01 )

~

University of Oxford, 10/28/2008

slide21

Inclusive search for squark/gluino

mSUGRA: Low tan b scenario (=5 for CDF, = 3 for D0)

Assume 5-flavors degenerate

q

Final state: energetic jets of hadrons and large unbalanced transverse energy(due to presence of c0)

~

q

~

~

~

c

c

0

0

g

q

g

~

A0 = 0, m<0

M0 [0,500 GeV/c2]

m1/2  [50,200 GeV/c2]

q

0

c

~

~

q

q

~

~

c

c

0

0

~

~

q

q

g

g

q

~

Mq ~ Mg

qg final state dominates

 3 jets expected

~

q

~

~

~

~

c

c

0

0

~

q

g

~

q

q

q

~

~

q

q

0

0

c

Mq > Mg

gg final state dominates

 4 jets expected

~

~

~

~

~

~

c

c

0

0

Mq < Mg

qq final state dominates

 2 jets expected

~

~

~

q

~

~

q

q

3 different analyses carried out with different jet multiplicities

Final selection based on Missing ET , HT = S (ETjets) and ET jets

University of Oxford, 10/28/2008

background rejection

DiBoson

Background rejection

Data sample Cleanup

  • at least one central jet with |h|<1.1
  • minimum missing ET of 70 GeV
  • Reject beam-related backgrounds and cosmics

Rejection of SM processes

QCD-multijet: ET due to jet energy mismeasurement.

W/Z+jets with Wl or Z, DiBoson

and tt production: Signaturesvery

similar to SUSY

Define signal region based on selections

that maximize background rejection

University of Oxford, 10/28/2008

qcd multijet rejection
QCD multijet rejection

Missing ET from mis-reconstructed jets

 Collinear with one of the leading jets

 Apply cuts on Df (missingET-jets)

  • CDF: remaining QCD-bkg estimatated from Monte Carlo.
  • Control checks in enhanced QCD-sample
  • DØ : QCD-bkg extrapolated in data by exponential fit function

Df(MET-jets)

cut reversed for

at least one of

the leading jets

University of Oxford, 10/28/2008

top and boson jets rejection

Z/g*

n

q

n

g

q

g

n

W

q

l

t

b

q’

W

q

q

t

b

Top and Boson+jets rejection

Control region

  • Genuine Missing ET in the event
  • Suppressed vetoing events with:
    • jetElectromagnetic fraction > 90%, to reject electrons mis-identified as jets
    • isolated tracks collinear to missing ETto reject undetected electrons/muons
  • Modeled using Monte Carlo
  • Normalized to NLO cross section
  • Define control regions reversing lepton vetoes  checks of background estimations
    • Understanding these processes is fundamental

Control region

University of Oxford, 10/28/2008

data vs sm predictions
DATA vs SM predictions

CDF

Good agreement between Observed and Expected events

Systematic uncertainties dominated by Jet Energy scale

University of Oxford, 10/28/2008

slide26

Exclusion limits: Mg -Mq andM0-M1/2 plane

~

~

Similar results for CDF and DØ

95% C.L. Exclusion limit

Results can be interpreted as a function of mSUGRA parameters

LEP limit improved in the region where 70<M0<300 GeV/c2and 130<M1/2<170 GeV/c2

~

~

For Mg=Mq → M > 392GeV/c2

Mg > 280 GeV/c2 in any case

~

University of Oxford, 10/28/2008

search for chargino neutralino

Lepton ET

Search for chargino/neutralino

mSUGRAc02c±1 pair production

Signature: three leptons and ET

  • Small cross sections (~0.1-0.5 pb)
  • Very low background:
    • Drell-Yan
    • Diboson(WW, WZ/*, ZZ/*, W)
    • Top pair production
    • QCD-multijets, W+jets

(misidentified leptons)

e,m,tLept, tHadr

  • CDF: 5 exclusive channels
    • combinations of “tight” (t) and “loose” (l) lepton categories
      • 3-leptons (e,m,tLept)
      • 2-leptons (e,m,tLept) + iso-track T (tHadr)
    • Ordered in terms of S/B
  • DØ: 4 analyses carried out
    • ee+IsoTrk, mm+IsoTrk, em+IsoTrk, Same-sign mm

ttt

tlT

ttl

tll

ttT

University of Oxford, 10/28/2008

c 0 2 c 1 results

3 tight leptons

selection

c02c±1 results

47 Dilepton and trilepton control regions defined to test SM predictions

CDF

Signal region:

Missing ET > 20 GeV + topological cuts

Njet=0,1 and ETjet < 80 GeV

(4 channels)

mSUGRA Benchmark:

m0=60 GeV/c2,

m1/2=190 GeV/c2,

tan=3, A0=0, >0

Data Observed : 3

SM Expected: 4.1  0.7

Good agreement between data and SM prediction  set limit

University of Oxford, 10/28/2008

excluded region in msugra
Excluded region in mSUGRA

excluded region in mSUGRA m0-m½ space for tan(β)=3, A0=0, μ>0

m0 = 60 GeV/c2

Exclude

mc±1< 145 GeV/c2

~

~

~

Small Dm = m(c20 )-m(l), soft leptons from c20 decay

 Loss in acceptance, no exclusion

University of Oxford, 10/28/2008

g auge m ediated s ymmetry b reaking
Gauge Mediated Symmetry Breaking
  • SUSY breaking at scale L (10 -100 TeV). Mediated by Gauge Fields (“messengers”)
  • Gravitino very light (<< MeV) and LSP
  • Neutralino or slepton can be NLSP
  • If NLSP is neutralino

In Rp conservation scenario:

 2 NLSP  2g + MET (+X) in final state

Snowmass p8 spectra

CDF Run I

(taken from N. Ghodbane et al., hep-ph/0201233)

University of Oxford, 10/28/2008

gg missing e t
gg+Missing ET
  • Assuming c01 (NLSP) short-lived
  • Very low SM background
    • Zgg nngg, Wgg lngg
  • Understanding of instrumental background challenging:
    • Mis-measured ET: use multijet data sample
    • e g misidentification: use W(en)g data

2 photons pTg > 25 GeV, |hg|<1.1

ET> 60 GeV

3 events (SM: 1.60.4)

University of Oxford, 10/28/2008

delayed photons
Delayed Photons
  • c01 life-time undetermined in GMSB  long-lifetime can be in ~ns range
  • Final state: Delayed photon+ET +jets

 ET> 40 GeV, pTg>25 GeV, ETjet > 35 GeV

 |h(g)|<1.1, |h(jet)|< 2.

Observed 2 events

SM Expect.: 1.30.7

M(c01)>101 GeV @ 5 ns

tc(g) in [2-10] ns range

University of Oxford, 10/28/2008

neutral mssm higgs
Neutral MSSM Higgs
  • In MSSM, two Higgs doublets
    • Three neutral (h, H, A), two charged (H±)
    • Properties of the Higgs sector largely determined by mA and tanb
    • Higher-order effects introduce other SUSY parameters
  • Large Higgs production cross section at large tanb.

Higgs decays:

BR(bb) : ~90%

Huge QCD background

BR(tt) :~10%

University of Oxford, 10/28/2008

bsm higgs
BSM Higgs: 
  • CDF and DØ  channel
    •  pure enough for direct production search
    • DØ adds associated production search: bb
  • Key issue: understanding  Id efficiency
    • Large calibration samples: W for Id optimization and Z for confirmation of Id efficiency

mA=140 GeV/c2

  • No Evidence for SUSY Higgs
    • Limits: tan vs mA
    •  generally sensitive at high tan

CDF: 

University of Oxford, 10/28/2008

searches beyond sm1

Searches Beyond SM

  • More ‘Exotic’ models…
  • - Extra-Dimensions
  • New Gauge bosons
search for high mass resonances
Search for high mass resonances

Example of di-lepton events

Transverse plane

  • Advantage
  • Sensitive to many BSM scenarios:
  • Extra-Dimensions
  • Extended SUSY-GUT groups
  • (SO(10),E6,E8...leading to additional gauge bosons, Z\' and W\')
  • R-parity violating SUSY
  • and more...
  • Di-lepton resonances have a strong track record for discovery → J/ψ, Υ, Z
    • Enlarge the possible final states looking also in dijet,ditop or dibosons!
  • Construct the pair invariant mass and look for any excesses in the high mass spectrum

University of Oxford, 10/28/2008

extra dimensions
Extra-Dimensions

M2Planck ~ Rn(MD)n+2 ,MD ~ 1 TeV

‘Solves’ the hierarchy problem by postulating that we live in more than 4 dimensions.

  • Large Extra Dimensions: Arkani-Hamed, Dimopoulos, Dvali (ADD)
    • Gravity propagate in ndadditional spatial dimensions compactified at radius R
    • Effective Planck scale:
    • no narrow resonances, SM particles pair production enriched by exchanged gravitons
  • Randall-Sundrum model: Only one extra dimensions (wraped) limited by two 4-dimensional brains.
    • SM particles live in one of the brains.
    • Graviton can travel in all 5 dimensions, appears as Kaluza-Klein towers
    • dimensionless coupling (k/MPl) free parameter

University of Oxford, 10/28/2008

search for high mass e e gg resonance
CDF: Central-Central (|1,2|<1) or Central-Forward (||<2) e+e- pair with ET>25 GeV

D0: EM objects pair (e+e- or gg), CC: |1,2|<1.1, CF 1.5<||<2.4

Major Backgrounds:

DrellYan

QCD (including W+jets)

Resonance search performed in mass range 150-1000 GeV/c2

No evidence for narrow resonances

 set limits

Search for High Mass e+e-/gg Resonance

CDF

Search for

RS Gkk resonance

University of Oxford, 10/28/2008

exclusion limits
Exclusion limits
  • CDF (D0) exclude RS graviton with mass below 850 (900) GeV/c2 for k/MPl=0.1
    • Can interpret results in term
    • of several other scenarios
  • Limits on extended gauge groups theories: SM-like Z’: 966 GeV/c2
  • Limits on effective Planck scale in LED:
    • Expect a cross section enhancement above SM
    • Use gg, e+e-

1.29 - 2.09 TeV depending on number of ED

University of Oxford, 10/28/2008

di muon resonances
Di-muon resonances

Spin 1 Z’-like limits

For the first time beyond one TeV for SM-Z\'!

Spin 0 (RPV sneutrinos):

mass limits up to 810 GeV

Spin 2 ( RS Graviton):

mass limits up to 921 GeV

  • Looking for narrow dimuon resonance decaying
    • Could have spin 0, 1 and 2
  • Search in 1/mμμin which detector resolution is ~const:

 17% inverse mass resolution at 1 TeV

 construct templates for several signal hypothesis, add bkg and compare to data

University of Oxford, 10/28/2008

and more
and more!

Every final state is currently investigated!!!

  • dijet resonances
    • Limits on several models, up to 1.2 TeV!
  • ditop resonances
    • limits on massive gluons and leptophobic Z\' (Mz\' > 760 GeV)
  • W\' in tb(+c.c.) or en final state
    • world\'s best limit MW\'→ en> 1 TeV
  • searches for t\' or b\'
    • fourth generation quarks not excluded by EWK
    • interesting tails in t\' → Wq
    • mt\' > 311 GeV

University of Oxford, 10/28/2008

final remarks

8.75 fb-1

7.29 fb-1

today

Highest Int. Lum

Lowest Int. Lum

Final remarks

Projection curves

FY10 start

In case we don’t find new particles @ Tevatron….

~ 1.8 fb-1 delivered in FY08

FY08 start

University of Oxford, 10/28/2008

CDF and D0 have a wide and rich program of searches for SUSY. No evidence yet, but.. expect to collect and analyze up to 8 fb-1 of data in the next years.

the future now almost present

7 TeV +

7 TeV

The Future …. now almost present

The Large Hadron Collider (LHC)

Proton- Proton Collider

ATLAS

CMS

First Event (9/10/2008)!

University of Oxford, 10/28/2008

roadmap to discovery
Roadmap to discovery

Higgsdiscoverysensitivity (MH=130~500 GeV)

Explore SUSY to m ~ TeV

Precision SM measurements

1 fb-1

Sensitivity to 1-1.5 TeV resonances → lepton pairs

Understand SM backgroundfor SUSY and Higgs

Jet energyscalecalibration

100 pb-1

Detector calibration

Use SM processes as “standardcandles”

10 pb-1

time

100 pb-1

  • High-pT lepton resonances may provide the first signal of New Physics:
    • Less sensitive to calorimeter performance

University of Oxford, 10/28/2008

jets measurements @ lhc

ATLAS preliminary

Jets measurements @ LHC

Ze+e-

50 pb-1

Jet energy scale

largest source of systematic error

initial uncertainty ~ 5-10%

Need to reduce error for QCD test

LHC (s = 14 TeV)

10 events with Ldt = 20 pb-1

Ldt=1fb-1

Tevatron

measure W/Z + jet(s) cross-section

γ/Z+jets calibration signal

University of Oxford, 10/28/2008

susy@lhc

RP-conserving mSUGRA

ATLAS preliminary

pTjets+ETmiss(GeV)

[email protected]

Excl

The LHC is built to discover SUSY

If there, we will find it relatively soon

An example:

squark-gluino production

  • But it will take a bit of time:
  • commissioning phase to understand detector performance and “re-discover” the SM

University of Oxford, 10/28/2008

sm higgs a challenge

ATLAS preliminary

H  ZZ*  4l

30 fb-1

The “golden” channel

SM Higgs: a challenge!

Required luminosity for 95% C.L. exclusion

For low mass of ~120 GeV need to combine many channels with small S/B or low statistics (H  , H→, H ZZ*  4l, H→ WW*→ll )

ATLAS

preliminary

most promising in the range 150-180 GeV, again with H → WW* →ll

 almost excluded at the Tevatron!

University of Oxford, 10/28/2008

conclusions
Conclusions

"Whatever" is beyond the Standard Model, these are exciting times for high energy physics!

LHC

TeVatron?

University of Oxford, 10/28/2008

higgs reach @ tevatron
Higgs reach @ Tevatron
  • With 7 fb-1
  • exclude all masses !!! [except real mass]
  • 3-sigma sensitivity 150:170
  • LHC’s sweet spot

X2.25

This is very compelling

7.0

University of Oxford, 10/28/2008

msugra

EWK GUT

mSUGRA
  • New superfields in “hidden” sector
  • Interact gravitationally with MSSM
  • Soft SUSY breaking

5 parameters at GUT scale

1. Unified gaugino mass m1/2

2. Unified scalar mass m0

3. Ratio of H1, H2 vevs tanβ

4. Trilinear coupling A0

5. Higgs mass term sgn()

In R parity conservation scenario,

the LSP is the neutralino (c01 )

University of Oxford, 10/28/2008

control regions cdf

2-leptons control region

MET (GeV)

Diboson

Signal?

10 15

DY + 

Z + fake

15 76 106

Invariant Mass (GeV/c2)

2-leptons+T

MET < 10 GeV

3-leptons

MET < 10 GeV

Control regions (CDF)

Dilepton and trilepton control regions defined to test SM predictions:  function of ET and the invariant mass of the 2 leading leptons

 47 in total!

University of Oxford, 10/28/2008

cdf jet energy scale
CDF Jet Energy Scale

Different correction factors:

  • (frel)Relative Corrections

 Make response uniform in h

  • (MPI)Multiple Particle Interactions

 Energy from different ppbar interaction

  • (fabs)Absolute Corrections

 Calorimeter non-linear and non-compensating

  • (UE)Underlying Event

 Energy associated with spectator partons

  • Jets are composite object:
  • complex underlying physics
  • depends on detector properties

PT jet(R) = [ PT jetraw(R)  frel (R) – MPI(R)]  fabs(R) - UE(R)

CDF Run II

Total systematic uncertainties for JES: between 2% and 3%

Absolute correction factor

University of Oxford, 10/28/2008

lhc msugra cross sections
LHC mSUGRA cross sections
  • Strongly interacting particles
  • High cross sections for gluinos andsquarksproduction
  •  Golden signature!

T. Plehn, PROSPINO

(pb)

University of Oxford, 10/28/2008

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