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Anticipating New
Physics at the LHC
LISHEP09
J Hewett, SLAC
Why New Physics @ the Terascale?
• Electroweak Symmetry breaks at
energies ~ 1 TeV
(SM Higgs or ???)
• WW Scattering unitarized at energies ~ 1 TeV
(SM Higgs or ???)
• Gauge Hierarchy: Nature is fine-tuned or
Higgs mass must be stabilized by
New Physics ~ 1 TeV
• Dark Matter: Weakly Interacting Massive
Particle must have mass ~ 1 TeV to
reproduce observed DM density
All things point to the Terascale!
A Cellar of New Ideas
’67
The Standard Model
’77
Vin de Technicolor
’70’s
’90’s
Supersymmetry: MSSM
SUSY Beyond MSSM
a classic!
aged to perfection
better drink now
mature, balanced, well
developed - the Wino’s choice
svinters blend
CP Violating Higgs
all upfront, no finish
lacks symmetry
’98
Extra Dimensions
bold, peppery, spicy
uncertain terrior
’02
Little Higgs
’90’s
’03
’03
’04
’05
Fat Higgs
Higgsless
Split Supersymmetry
Twin Higgs
complex structure
young, still tannic
needs to develop
sleeper of the vintage
what a surprise!
finely-tuned
double the taste
J. Hewett
Last Minute Model Building
Anything Goes!
•
•
•
•
•
•
•
Non-Communtative Geometries
Return of the 4th Generation
Hidden Valleys
Quirks – Macroscopic Strings
Lee-Wick Field Theories
Unparticle Physics
…..
(We stilll have a bit more time)
The Hierarchy Problem
Energy (GeV)
Planck
GUT
10
Weak
Quantum Corrections:
Virtual Effects drag
Weak Scale to MPl
desert
1019
1016
LHC
3
mH2 ~
All of
known
physics
10-18
Solar System
Gravity
~ MPl2
The Hierarchy Problem: Little Higgs
Energy (GeV)
1019
1016
.
.
.
LHC
Planck
GUT
106
105
104
New Physics!
New Physics!
New Physics!
10
Weak
3
All of
known
physics
10-18
Solar System
Gravity
Stacks of Little
Hierarchies
Simplest Model:
The Littlest Higgs with
1 ~ 10 TeV
2 ~ 100 TeV
3 ~ 1000 TeV
…..
3-Scale Model
 ~ 10 TeV: New Strong Dynamics
Global Symmetry
f ~ /4 ~ TeV:
v ~ f/4 ~ 100 GeV:
Sample Spectrum
Symmetires Broken
Pseudo-Goldstone Scalars
New Gauge Fields
Signal @ LHC
New Fermions
Light Higgs
SM vector bosons & fermions
The Hierarchy Problem: Extra Dimensions
Energy (GeV)
Planck
GUT
Simplest Model:
Large Extra Dimensions
desert
1019
1016
LHC
10
3
Weak – Quantum Gravity
= Fundamental scale in
4 +  dimensions
MPl2 = (Volume) MD2+
All of
known
physics
Gravity propagates in
D = 3+1 +  dimensions
10-18
Solar System
Gravity
Arkani-Hamed, Dimopoulis, Dvali
Kaluza-Klein Gravitons in a Detector
Indirect Signature
Missing Energy Signature
pp  g + Gn
Events / 50 GeV / 100 fb-1
LHC
102
10
1
10-1
10-2
JLH
Mee [GeV]
Vacavant, Hinchliffe
Signals for Gravitational Fixed Points
Drell-Yan
t=
SM
1
0.5
D=3+4
M* = 4 TeV
• Fixed point renders GR
non-perturbatively
renormalizable and
asymptotically safe
• Gravity runs such that it
becomes weaker at higher
energies
• Collider signals if √s ~ MPl
• Graviton Exchange
Modified
• Graviton Emission generally
unaffected
• Parameterize by form
factor in coupling
• Could reduce signal!
JLH, Rizzo, arXiv:0707.3182
Litim, Pheln, arXiv:0707.3983
The Hierarchy Problem: Extra Dimensions
Energy (GeV)
Planck
GUT
desert
1019
1016
LHC
Model II:
Warped Extra Dimensions
strong
curvature
10
3
Weak
wk = MPl e-kr
All of
known
physics
10-18
Solar System
Gravity
Randall, Sundrum
Kaluza-Klein Gravitons in a Detector:
SM on the brane
Number of Events in Drell-Yan
For this same model
embedded in a string
theory: AdS5 x S
Spin-2 resonances in Drell-Yan
Davoudiasl, JLH, Rizzo
Kaluza-Klein Modes in a Detector: SM
off the brane
Fermion wavefunctions in the bulk:
decreased couplings to light
fermions for gauge & graviton KK
states
gg  gn  tt
gg  Gn  ZZ
Lillie, Randall, Wang, hep-ph/0701164
Agashe, Davoudiasl, Perez, Soni hep-ph/0701186
Issue: Top Collimation
g1 = 2 TeV
gg  gn  tt
g1 = 4 TeV
Lillie, Randall, Wang, hep-ph/0701164
The Hierarchy Problem: Higgsless
Energy (GeV)
Planck
GUT
desert
1019
1016
LHC
Warped Extra Dimensions
strong
curvature
10
3
Weak
wk = MPl e-kr
With NO Higgs boson!
All of
known
physics
10-18
Solar System
Gravity
Csaki, Grojean,Murayama, Pilo, Terning
Framework: EW Symmetry Broken by Boundary
Conditions
SU(2)L x SU(2)R x U(1)B-L in 5-d Warped bulk
Planck
brane
TeV-brane
SU(2)L x SU(2)R
SU(2)R x U(1)B-L
U(1)Y
WR, ZR get
Planck
scale masses
SU(2)D
BC’s restricted by variation
of the action at boundary
SU(2) Custodial Symmetry
is preserved!
W, Z get TeV scale masses
 left massless!
Unitarity in Gauge Boson Scattering: What do
we do without a Higgs?
Exchange gauge
KK towers:
Conditions on KK masses & couplings:
Csaki etal, hep-ph/0305237
(g1111)2 = k (g11k)2
4(g1111)2 M12 = k (g11k)2 Mk2
Necessary, but not sufficient, to guarantee perturbative unitarity!
Some tension with precision EW
Production of Gauge KK States @ LHC
gg, qq  g1  dijets
Davoudiasl, JLH, Lilllie, Rizzo
Balyaev, Christensen
The Hierarchy Problem: Who Cares!!
Planck Scale
Gauge Hierarchy Problem
Weak Scale
Cosmological Constant Problem
Cosmological
Scale
We have much bigger Problems!
Split Supersymmetry:
Energy
(GeV)
Arkani-Hamed, Dimopoulis hep-ph/0405159
Giudice, Romanino hep-ph/0406088
MGUT ~ 1016 GeV
MS : SUSY broken at high scale ~ 109-13 GeV
Scalars receive mass @ high scale
Mweak
1 light Higgs + Fermions
protected by chiral
symmetry
Collider Phenomenology: Gluinos
•
•
•
•
•
Pair produced via strong interactions as usual
Gluinos are long-lived
No MET signature
Form R hadrons
Monojet signature from gluon bremstrahlung
q
Gluino pair + jet cross section
1 0
~
~
g
q
q
100 fb-1
Rate ~ 0, due to heavy
squark masses!
JLH, Lillie, Masip, Rizzo hep-ph/0408248
The Hierarchy Problem: Supersymmetry
Energy (GeV)
Planck
GUT
Quantum Corrections:
Virtual Effects drag
Weak Scale to MPl
desert
1019
1016
LHC
boson
10
3
Weak
fermion
mH2 ~
All of
known
physics
10-18
~ MPl2
mH2 ~
Solar System
Gravity
~ - MPl2
Large virtual effects cancel
order by order in
perturbation theory
Supersymmetry With or Without Prejudice?
• The Minimal Supersymmetric Standard Model has
~120 parameters
• Studies/Searches incorporate simplified versions
– Theoretical assumptions @ GUT scale
– Assume specific SUSY breaking scenarios (mSUGRA, GMSB,
AMSB)
– Small number of well-studied benchmark points
• Studies incorporate various data sets
• Does this adequately describe the true breadth of
the MSSM and all its possible signatures?
• The LHC is turning on, era of speculation will end,
and we need to be ready for all possible signals
Most Analyses Assume CMSSM Framework
• CMSSM: m0, m1/2, A0, tanβ, sign μ
• Χ2 fit to some global data set
Prediction for Lightest Higgs Mass
Fit to EW precision, B-physics observables, & WMAP
Ellis etal arXiv:0706.0652
Spectrum for Best Fit CMSSM/NUHM Point
NUHM includes two more parameters: MA, μ
Buchmuller etal arXiv:0808.4128
Gluinos at the Tevatron
Alwall, Le, Lisanti, Wacker arXiv:0803.0019
• Tevatron gluino/squark analyses performed solely
for mSUGRA – constant ratio mgluino : mBino ≃ 6 : 1
Gluino-Bino mass
ratio determines
kinematics
More Comprehensive MSSM Analysis
Berger, Gainer, JLH, Rizzo, arXiv:0812.0980
• Study Most general CP-conserving MSSM
– Minimal Flavor Violation
– Lightest neutralino is the LSP
– First 2 sfermion generations are degenerate w/ negligible
Yukawas
– No GUT, high-scale, or SUSY-breaking assumptions
• ⇒ pMSSM: 19 real, weak-scale parameters
scalars:
mQ1, mQ3, mu1, md1, mu3, md3, mL1, mL3, me1, me3
gauginos: M1, M2, M3
tri-linear couplings: Ab, At, Aτ
Higgs/Higgsino: μ, MA, tanβ
Perform 2 Random Scans
Linear Priors
107 points – emphasize
Log Priors
2x106 points – emphasize
100 GeV  msfermions  1 TeV
50 GeV  |M1, M2, |  1 TeV
100 GeV  M3  1 TeV
~0.5 MZ  MA  1 TeV
1  tan  50
|At,b,|  1 TeV
100 GeV  msfermions  3 TeV
moderate masses
lower masses and extend to
higher masses
10 GeV  |M1, M2, |  3 TeV
100 GeV  M3  3 TeV
~0.5 MZ  MA  3 TeV
1  tan  60
10 GeV ≤|A
t,b,|
 3 TeV
Absolute values account for possible phases
only Arg (Mi ) and Arg (Af ) are physical
2
. Stops/sbottoms
• Check meson
mixing
Set of Experimental Constraints
• Theoretical spectrum Requirements (no tachyons, etc)
• Precision measurements:
– Δ, (Z→ invisible)
– Δ(g-2) ??? (30.2  8.8) x 10-10
(0809.4062)
(29.5  7.9) x 10-10
(0809.3085)
→ (-10 to 40) x 10-10
to be conservative..
• Flavor Physics
– b →s , B →τν, Bs →μμ
– Meson-Antimeson Mixing : Constrains 1st/3rd sfermion mass
ratios to be < 5 in MFV context
Set of Experimental Constraints Cont.
• Dark Matter
– Direct Searches: CDMS, XENON10, DAMA, CRESST I
– Relic density: h2 < 0.1210 → 5yr WMAP data
• Collider Searches: complicated with many caveats!
– LEPII: Neutral & Charged Higgs searches
Sparticle production
Stable charged particles
– Tevatron: Squark & gluino searches
Trilepton search
Stable charged particles
BSM Higgs searches
Slepton & Chargino Searches at LEPII
Sleptons
Charginos
Tevatron Squark & Gluino Search
2,3,4 Jets + Missing Energy (D0)
Multiple analyses keyed to
look for:
Squarks-> jet +MET
Gluinos -> 2 j + MET
Feldman-Cousins 95% CL
Signal limit: 8.34 events
For each model in our scan
we run SuSpect -> SUSY-Hit
-> PROSPINO -> PYTHIA ->
D0-tuned PGS4 fast
simulation and compare to
the data
Tevatron: D0 Stable Particle (= Chargino) Search
sleptons
winos
higgsinos
Interpolation: M > 206 |U1w|2 + 171 |U1h|2 GeV
•This is an incredibly powerful constraint on our
model set!
•No applicable bounds on charged sleptons..the cross
sections are too small.
Survival Statistics
• Flat Priors:
– 107 models scanned
– 68.5K (0.68%)
survive
• Log Priors:
– 2 x106 models
scanned
– 3.0k (0.15%) survive
9999039 slha-okay.txt
7729165 error-okay.txt
3270330 lsp-okay.txt
3261059 deltaRho-okay.txt
2168599 gMinus2-okay.txt
617413 b2sGamma-okay.txt
594803 Bs2MuMu-okay.txt
592195 vacuum-okay.txt
582787 Bu2TauNu-okay.txt
471786 LEP-sparticle-okay.txt
471455 invisibleWidth-okay.txt
468539 susyhitProb-okay.txt
418503 stableParticle-okay.txt
418503 chargedHiggs-okay.txt
132877 directDetection-okay.txt
83662
neutralHiggs-okay.txt
73868
omega-okay.txt
73575
Bs2MuMu-2-okay.txt
72168
stableChargino-2-okay.txt
71976
triLepton-okay.txt
69518
jetMissing-okay.txt
68494
final-okay.txt
ATLAS
CMS
SU1
SU2
SU3
SU4
SU8
LM1
LM2
LM3
LM4
LM5
LM6
LM7
LM8
LM9
LM10
HM2
HM3
HM4
OK
killed by LEP
killed by h2
killed by b→s
killed by g-2
killed by Higgs
killed by g-2
killed by b→s
killed by h2
killed by h2
OK
killed by LEP
killed by h2
killed by LEP
OK
killed by h2
killed by h2
killed by h2
Fate of Benchmark
Points!
Most well-studied
models do not
survive confrontation
with the latest data.
For many models this
is not the unique
source of failure
Similarly for the SPS Points
SPS1a
killed by b →s
SPS1a’
OK
SPS1b
killed by b →s
SPS2
killed by h2 (GUT) / OK(low)
SPS3
killed by h2 (low) / OK(GUT)
SPS4
killed by g-2
SPS5
killed by h2
SPS6
OK
SPS9 killed by Tevatron stable chargino
Predictions for Observables (Flat Priors)
b → sγ
g-2
Exp’t
SM
Bs →μμ
BSM = 3.5 x 10-9
Relic Density
Predictions for Lightest Higgs Mass
Flat Priors
Log Priors
Predictions for Heavy & Charged Higgs
Flat Priors
tan β
Distribution of Squark Masses
Flat Priors
Stops
Sbottoms
Distribution of Gaugino Masses
Flat Priors
Gluino
Charginos
Neutralinos
Composition of the LSP
Flat Priors
Log Priors
Character of the NLSP: it can be anything!
Flat Priors
Log Priors
NLSP-LSP Mass Splitting
Flat Priors
NLSP-LSP Mass Splitting: Details
~
Χ 20
~
Χ 1+
~
eR
~
u
L
Naturalness Criterion
Barbieri, Giudice
Kasahara, Freese, Gondolo
Flat Priors
Less
Log Priors
More
Fine tuned
Δ
Δ
Flat Priors
Log Priors
We have many
more
classifications!
Flat Priors:
1109 Classes
Log Priors:
267 Classes
The LHC is Turning On!!!!!!!!
What can BSM theorists do until the data starts
pouring in?
• More & more New Models:
New models are most useful if they contain new signatures
Biggest worry is whether triggers cover all NP possibilities
• Fully compute the signatures of current NP models
• Fully implement NP models into Monte Carlos
Let the fun begin!
Discoveries at the
LHC will find the
vintage nature has
bottled.
Back-up
ILC Search Region: Sleptons and EW Gauginos
Flat Priors: MSUSY ≤ 1 TeV
Log Priors: MSUSY ≤ 3 TeV
x-axis
legend
ILC Search Region: Squarks and Gluinos
Flat Priors: MSUSY ≤ 1 TeV
Log Priors: MSUSY ≤ 3 TeV
Black Hole Production @ LHC:
Dimopoulos, Landsberg
Giddings, Thomas
Black Holes produced when s > M*
Classical Approximation:
E/2
b
[space curvature << E]
b < Rs(E)  BH forms
E/2
Geometric Considerations:
Naïve = Rs2(E),
details show this holds up to a factor
of a few
Production rate is enormous!
Determination of Number
of Large Extra Dimensions
1 per sec at LHC!
JLH, Lillie, Rizzo
hep-ph/0503178
Black-Max: a New BH Generator
Dai, Starkman, Stojkevic, Issever, Rizvi, Tseng,
arXiv:0711.3012
• Simulates more
realistic models
– Greybody factors
– BH rotation
– BH recoil due to
Hawking radiation
– Brane tension
– Split fermions
• Dramatic effects
on kinematic
properties
• Interfaces w/
Herwig & Pythia
Energy Distbt’n of emitted particles
No new
effects
Split Fermions
Brane
tension
Rotating
Distribution for Selectron/Sneutrino Masses
Flat Priors
Log Priors
Distribution of Stau Masses
Flat Priors
Log Priors
Dark Matter Direct Detection Cross Sections
Flat Priors
Log Priors
Spin Dependent
Spin
Spin Independent
Independent
Distinguishing Dark Matter Models
Barger etal
Flat Priors
Little Higgs Gauge Production
WZ  WH  WZ  2j + 3l + 
Azuelos etal, hep-ph/0402037
Birkedal, Matchev, Perelstein, hep-ph/0412278
Density of Stopped Gluinos in ATLAS
Arvanitaki, etal hep-ph/0506242
See also ATLAS study, Kraan etal hep-ph/0511014