Transcript bjetcorr_update - University of Oxford

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

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 ...
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
2
The missing piece: the Higgs

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
WOULD THE HIGGS DISCOVERY
COMPLETE OUR UNDERSTANDING OF NATURE ?
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
3
Beyond SM: the Unknown
The Standard Model is theoretically incomplete
f
H
• Mass hierarchy problem
 radiative correction in Higgs sector
• Unification
DmH2 ~ L2
L = Mpl ?

• Dark Matter
• Matter-antimatter asymmetry
Many possible new particles and theories





SuperSymmetry
Extra Dimension
New Gauge groups (Z’, W’)
New fermions (e*, t’, b’ …)
…
Monica D'Onofrio, IFAE
Can show up in direct
searches or as subtle
deviations in precision
measurements
University of Oxford, 10/28/2008
4
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:



GMSB-inspired searches




Diphoton+X
Delayed photon analysis
MSSM Higgs
Extra-dimension and new gauge bosons:


Squark/gluino
Chargino/neutralinos
Search for high-mass resonances
Perspectives for the LHC
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
5
The Tevatron
p
Highest-energy accelerator
currently operational
CDF
_
p
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)
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
6
CDF and DØ in RunII
CDF
D0
Took >1 years of collisions to
get to stable high efficiency
Oct 08
Jan 02
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
7
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!
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
8
Knowledge of the SM: QCD and EWK
Test of Next-to-Leading Order
perturbative QCD

inclusive jet cross section



Probing distances ~10-19 m
Constrains gluon PDF at high-x
Z(e+e-)+jets



Clean signature, low background
Test ground for Monte Carlo tools
W Mass and width
MW = 80413±48 MeV
GW = 2032±73 MeV
world’s most precise single measurements!
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
9
Knowledge of SM: top physics


Top quark discovered at the Tevatron in 1995
Very extensive program on top physics:


Precision measurements of top mass
Top cross sections, properties…
Mtop = 172.4 ± 0.7 (stat) ± 1.0 (syst) GeV/c2
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
10
Knowledge of SM: rare processes

Evidence of Single top production
D0: s + t = 4.7 ± 1.3 pb
CDF: s + t = 2.0-2.7 pb (± 0.7 pb per analysis)

DiBoson cross sections
Measurements of W/Z,
WW and WZ cross 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
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
11
Needle in the haystack



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.
 Model-inspired searches



Theory driven
Model-dependent optimization
of event selection
Set limits on model parameters
Monica D'Onofrio, IFAE
 Signature-based searches



Signature driven
Optimize selection to reduce
backgrounds
Event count; event kinematics
University of Oxford, 10/28/2008
12
The SM Higgs Boson
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
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
14
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 

E T  i ETi ni
2 leptons: e,,→e, (must have opposite 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
Analysis
Monica D'Onofrio, IFAE
Lum
Higgs
Exp.
Obs.
(fb-1)
Events
Limit
Limit
CDF ME+NN
3.0
17.2
1.6
1.6
DØ NN
3.0
15.6
1.9
2.0
University of Oxford, 10/28/2008
15
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
A 15 GeV window [162:177] excluded @ 90% CL
Monica D'Onofrio, IFAE
Low mass combination difficult due to
~70 channels: Expected sensitivity of
CDF/DØ combined: <3.0xSM @ 115GeV
University of Oxford, 10/28/2008
16
Searches Beyond SM
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
HU , HD 
 h, H, A, H 

Define R-parity = (-1)3(B-L)+2s

R = 1 for SM particles

R = -1 for MSSM partners
Monica D'Onofrio, IFAE
If conserved, provides
Dark Matter Candidate
(Lightest Supersymmetric Particle)
University of Oxford, 10/28/2008
18
Symmetry breaking
No SUSY particles found yet:



SUSY must be broken L  LSUSY  LSoft
More than 100 parameters even in minimal (MSSM) models
Breaking mechanism determines phenomenology and
search strategy at colliders:

Direct searches or subtle deviations in precision measurements
mSUGRA,
GMSB,
….
choose a model 
gravity
SUSY
breaking
(hidden
sector)
or
MSSM
(visible
sector)
Gauge fields,
loop effects….
Constrained MSSM models used as benchmark
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
19
Sparticles mass and cross sections
 in mSUGRA, new superfields in “hidden” sector
 Interact gravitationally with MSSM
 5 parameter at GUT scale
A0  300, tan   6,   0


M(+) ~ M(02) ~ 2M(01)
~ ~ 3M(+)
M(g)
Monica D'Onofrio, IFAE
2. Unified scalar mass m0
3. Ratio of H1, H2 vevs tanβ
4. Trilinear coupling A0
5. Higgs mass term sgn()
T. Plehn, PROSPINO
 (pb)
m0  100GeV , m1/ 2  300GeV
1. Unified gaugino mass m1/2
m (GeV)
Squarks and gluinos are heavy
Sizeable Chargino/neutralino cross sections
In R parity conservation scenario,
the LSP is the neutralino (01 )
University of Oxford, 10/28/2008
20
Inclusive search for squark/gluino
mSUGRA: Low tan  scenario (=5 for
CDF, = 3 for D0)
Assume 5-flavors degenerate
A0 = 0, <0
M0  [0,500 GeV/c2]
m1/2  [50,200 GeV/c2]
q
g~
q
q~
~0
~
q
g~
q
g~
g
q
M~q ~
~~
q
q
q
~0
q
q~
~0
~0
~
Final state: energetic jets of hadrons
and large unbalanced transverse
energy (due to presence of 0)
q
Mg~
qg final state dominates
 3 jets expected
q
q
q
~~
gg
final state dominates
Mq~ < Mg~
 4 jets expected
q~
~0
~
Mq~ > Mg~
q
q
q
~~
qq final state dominates
 2 jets expected
3 different analyses carried out with different jet multiplicities
Final selection based on Missing ET , HT = S (ETjets) and ET jets
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
21
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.
DiBoson
W/Z+jets with Wl or Z, DiBoson
and tt production: Signatures very
similar to SUSY
Define signal region based on selections
that maximize background rejection
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
22
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
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
23
Top and Boson+jets rejection
Z/*
q


g
q
g
q
t
W
q

W
t
b
l
q’
q
b

Genuine Missing ET in the event

Suppressed vetoing events with:

Control region
jet Electromagnetic fraction > 90%,
to reject electrons mis-identified as jets

isolated tracks collinear to missing ET
to reject undetected electrons/muons

Modeled using Monte Carlo

Normalized to NLO cross section

Control region
Define control regions reversing
lepton vetoes  checks of
background estimations

Understanding these processes is
fundamental
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
24
DATA vs SM predictions
DØ
CDF
CDF
Data
Expected SM
2 jets
3 jets
4 jets(gluino)
HT>330, ET>180GeV/c2
HT>330, ET>120GeV/c2
HT>280, ET>90GeV/c2
18
38
45
165
3712
4717
HT>375, ET>175GeV/c2
HT>400,ET>100GeV/c2
11
9
20
11.11.2
10.70.9
17.71.1
HT>330, ET>225GeV/c2
D0
Data
Expected SM
Good agreement between Observed and Expected events
Systematic uncertainties dominated by Jet Energy scale
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
25
Exclusion limits: Mg~ -Mq~ and M0-M1/2 plane
Similar results for CDF and DØ
95% C.L. Exclusion limit
Results can be interpreted as a
function of mSUGRA parameters
For Mg~=Mq~ → M > 392 GeV/c2
Mg~ > 280 GeV/c2 in any case
Monica D'Onofrio, IFAE
LEP limit improved in the region
where 70<M0<300 GeV/c2 and
130<M1/2<170 GeV/c2
University of Oxford, 10/28/2008
26
Search for chargino/neutralino
mSUGRA 02 ±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,,Lept, Hadr

CDF: 5 exclusive channels

ttt
Lepton ET
combinations of “tight” (t) and “loose” (l)
lepton categories

ttl tll ttT tlT


3-leptons (e,,Lept)
2-leptons (e,,Lept) + iso-track T (Hadr)

DØ: 4 analyses carried out

ee+IsoTrk, +IsoTrk,
e+IsoTrk, Same-sign 
Ordered in terms of S/B
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
27
02 ±1 results
CDF
47 Dilepton and trilepton control
regions defined to test SM predictions
Signal region:
Missing ET > 20 GeV +
topological cuts
Njet=0,1 and ETjet < 80 GeV
channel
Trilepton
(3 channels)
dilepton + track
(2 channels)
mSUGRA Signal
SM Expected
DATA
4.5  0.2  0.4
0.88  0.05  0.13
1
6.9 0.2  0.7
5.5  0.7  0.9
6
DØ
3 tight leptons
selection
mSUGRA Benchmark:
m0=60 GeV/c2,
m1/2=190 GeV/c2,
tan=3, A0=0, >0
(4 channels)
Data Observed : 3
SM Expected: 4.1  0.7
Good agreement between data
and SM prediction  set limit
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
28
Excluded region in mSUGRA
excluded region in mSUGRA m0-m½ space for tan(β)=3, A0=0, μ>0
m0 = 60 GeV/c2
Exclude
m±1 < 145 GeV/c2
~ soft leptons from ~ 0 decay
Small Dm = m(~20 )-m(l),
2
 Loss in acceptance, no exclusion
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
29
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
~
0
~
 1  G
L  100 TeV
Nm  1
Mm  2L
t an  15
 0
In Rp conservation scenario:
 2 NLSP  2 + MET (+X) in final state
Snowmass p8 spectra
CDF Run I
(taken from N. Ghodbane et al., hep-ph/0201233)
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
30
+Missing ET


Assuming 01 (NLSP) short-lived
Very low SM background


Z , W l
Understanding of instrumental
background challenging:


Mis-measured ET: use multijet data sample
e  misidentification: use W(e) data
2 photons pT > 25 GeV, |h|<1.1
ET> 60 GeV
3 events (SM: 1.60.4)
L  91.5 TeV @ 95% CL
M(10 )  125 GeV, M(1 )  229 GeV
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
31
 
|
x
 xi |
t cγ  t f  t i  f
c
Delayed Photons


01 life-time undetermined in GMSB
 long-lifetime can be in ~ns range
Final state: Delayed photon+ET +jets
 ET> 40 GeV, pT>25 GeV, ETjet > 35 GeV
 |h()|<1.1, |h(jet)|< 2.
tc() in [2-10] ns range
Monica D'Onofrio, IFAE
Observed 2 events
SM Expect.: 1.30.7
University of Oxford, 10/28/2008
M(01)>101 GeV @ 5 ns
32
MSSM Higgs
Neutral MSSM Higgs


In MSSM, two Higgs doublets
HU , HD 
 h, H, A, H 

Three neutral (h, H, A), two charged (H±)

Properties of the Higgs sector largely determined by mA and tan

Higher-order effects introduce other SUSY parameters
Large Higgs production cross section at large tan.
Higgs decays:
BR(bb) : ~90%
Huge QCD background
BR() : ~10%
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
34
BSM Higgs: f

pvis1  pvis2  p T
CDF and DØ f channel

 pure enough for direct production search

DØ adds associated production search: bfb


mvis 
Key issue: understanding  Id efficiency

Large calibration samples: W for Id
optimization and Z for confirmation of Id
efficiency
No Evidence for SUSY
Higgs
mA=140
GeV/c2
Limits: tan vs mA
f generally
sensitive at high
tan
Monica D'Onofrio, IFAE
CDF: f
University of Oxford, 10/28/2008
35
Searches Beyond SM
More ‘Exotic’ models…
- Extra-Dimensions
- New Gauge bosons
Search for high mass resonances

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
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...
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
37
Extra-Dimensions
‘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 nd additional spatial
dimensions compactified at radius R

Effective Planck scale:
M2Planck ~ Rn(MD)n+2 , MD ~ 1 TeV


no narrow resonances, SM particles pair
production enriched by exchanged gravitons
Randall-Sundrum model: Only one extra
dimensions (wraped) limited by two 4dimensional 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
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
38
Search for High Mass
e+e- / Resonance
CDF
Search for
RS Gkk resonance


CDF: Central-Central (|h1,2|<1) or CentralForward (|h|<2) e+e- pair with ET>25 GeV
D0: EM objects pair (e+e- or ),
CC: |h1,2|<1.1, CF 1.5<|h|<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
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
39
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 effective Planck scale in LED:
Limits on extended gauge groups
theories: SM-like Z’: 966 GeV/c2
 Expect a cross section enhancement above SM
 Use , e+e-
1.29 - 2.09 TeV
depending on
number of ED
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
40
Di-muon resonances

Looking for narrow dimuon resonance
decaying


Could have spin 0, 1 and 2
Search in 1/mμμ in which detector
resolution is ~const:
 17% inverse mass resolution at 1 TeV
 construct templates for several signal
hypothesis, add bkg and compare to data
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
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
41
and more!

dijet resonances


ditop resonances


Model
870 GeV/c2
Excited quark
1110 GeV/c2
Color-octet technirho
1250 GeV/c2
Axigluon & coloron
630 GeV/c2
E6 diquark
limits on massive gluons and
leptophobic Z' (Mz' > 760 GeV)
W' in tb(+c.c.) or e final state


Limits on several models, up to 1.2
TeV!
mass exclusion
world's best limit MW'→ e > 1 TeV
searches for t' or b'



fourth generation quarks not
excluded by EWK
interesting tails in t' → Wq
mt' > 311 GeV
Every final state is currently investigated!!!
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
42
Final remarks
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.
Projection curves
Projected Integrated Luminosity in Run II (fb -1) vs time
10
9
FY10 start
8.75 fb-1
8
today
Integrated Luminosity (fb -1)
7
7.29 fb-1
In case we don’t
Highest Int. Lum
Lowest Int. Lum find new particles
@ Tevatron….
6
5
~ 1.8 fb-1 delivered in FY08
4
3
2
FY08 start
1
10
0
11
/1
3
/2
0
/2
01
9
4/
27
/9
/
20
0
9
10
/2
00
3/
23
8
20
08
9/
4/
/2
00
2/
17
7
20
07
8/
1/
/2
00
6
1/
13
/2
00
5
6/
27
/9
/
20
0
5
12
/2
00
4
5/
23
/4
/
20
0
4
11
/2
00
4/
18
10
/1
/
20
0
3
0
time since FY04
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
43
The Future …. now almost present
The Large Hadron Collider (LHC)
Proton- Proton Collider
7 TeV + 7 TeV
ATLAS
CMS
First Event (9/10/2008)!
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
44
Roadmap to discovery
Higgs discovery sensitivity (MH=130~500 GeV)
Explore SUSY to m ~ TeV
1 fb-1
Precision SM measurements
Sensitivity to 1-1.5 TeV resonances → lepton pairs
100 pb-1
Understand SM background for SUSY and Higgs
Jet energy scale calibration
Detector calibration
10 pb-1
Use SM processes as “standard candles”
time

High-pT lepton resonances may
provide the first signal of New
Physics:

Less sensitive to calorimeter
performance
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
100 pb-1
45
Jets measurements @ LHC
Ze+e-
50 pb-1
LHC (s = 14 TeV)
10 events with
Ldt = 20 pb-1
Ldt=1fb-1
ATLAS preliminary
Tevatron
Jet energy scale
largest source of systematic error
initial uncertainty ~ 5-10%
Need to reduce error for QCD test
measure W/Z + jet(s) cross-section
γ/Z+jets calibration signal
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
46
SUSY@LHC
Excl
The LHC is built to discover SUSY
If there, we will find it relatively soon
An example:
squark-gluino
production
RP-conserving mSUGRA
ATLAS preliminary
But it will take a bit of time:
• commissioning phase to
understand detector performance
and “re-discover” the SM
SpTjets+ETmiss(GeV)
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
47
SM Higgs: a challenge!
Required luminosity for 95% C.L. exclusion
ATLAS
preliminary
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
H  ZZ*  4l
30 fb-1
The “golden” channel
most promising in the range 150-180 GeV, again with H → WW* →ll
 almost excluded at the Tevatron!
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
48
Conclusions
"Whatever" is beyond the Standard Model, these
are exciting times for high energy physics!
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
49
Back up
Higgs reach @ Tevatron
X2.25
With 7 fb-1
• exclude all masses !!!
[except real mass]
• 3-sigma sensitivity 150:170
LHC’s sweet spot
This is very compelling
7.0
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
52
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 (01 )
Monica D'Onofrio, IFAE
EWK
University of Oxford, 10/28/2008
GUT
53
Control regions (CDF)
Dilepton and trilepton
control regions defined
to test SM predictions:
 function of ET and the
2-leptons control region
invariant mass of the 2
leading leptons
Signal?
Diboson
DY + 
Z + fake
2-leptons+T
MET < 10 GeV
3-leptons
MET < 10 GeV
10
15
MET (GeV)
 47 in total!
15
76
106
Invariant Mass (GeV/c2)
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
54
CDF Jet Energy Scale
Jets are
composite object:
•complex underlying
physics
•depends on
detector properties
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
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
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
55
LHC mSUGRA cross sections
• Strongly interacting particles
• High cross sections for gluinos and squarks production
 Golden signature!
T. Plehn, PROSPINO
 (pb)
Monica D'Onofrio, IFAE
University of Oxford, 10/28/2008
56