Transcript Standard Model is an Effective Theory

Extra Dimensions: From Colliders
to Cosmology
• Large Extra Dimensions
(Primordial Black Holes)
• Universal Extra
Dimensions (KK Bino)
• Warped Extra
Dimensions (KK R )
Collider signals & DM
properties*
* Thanks to T. Tait!
J. Hewett
Michell Symposium 2007
Kaluza-Klein tower of particles
E2 = (pxc)2 + (pyc)2 + (pzc)2 + (pextrac)2 + (mc2)2
pextra is quantized = n/R
Small radius
gives well
separated
Kaluza-Klein
particles
In 4 dimensions,
looks like a mass!
Tower of massive particles
Small radius
Large radius
Large
radius gives
finely
separated
KaluzaKlein
particles
Large Extra Dimensions
Arkani-Hamed, Dimopoulos, Dvali,
SLAC-PUB-7801
Motivation: solve the hierarchy problem by removing it!
SM fields confined to 3-brane
Gravity becomes strong in the bulk
Gauss’ Law:
MPl2 = V MD2+ , V = Rc 
MD = Fundamental scale in the bulk
~ TeV
Kaluza-Klein Modes in a Detector
Indirect Signature
Missing Energy Signature
pp  g + Gn
JLH
Vacavant, Hinchliffe
Graviton Exchange Modified with Running
Gravitational Coupling
t=
SM
1
0.5
Insert Form Factor in
coupling to parameterize
running
M*D-2 [1+q2/t2M*2 ]-1
Could reduce signal!
D=3+4
M* = 4 TeV
JLH, Rizzo, to appear
Constraints from Astrophysics/Cosmology
• Supernova Cooling
Cullen, Perelstein
Barger etal, Savage etal
NN  NN + Gn can cool supernova too rapidly
• Cosmic Diffuse  Rays
NN  NN + Gn 
-  G  

n
• Matter Dominated Universe
Hannestad, Raffelt
Hall, Smith
Fairbairn
too many KK states
• Neutron Star Heat Excess
NN  NN + Gn
Hannestad, Raffelt
becomes trapped in neutron star halo
and heats it
Astrophysical Constaints*: MD in TeV
Hannestad, Raffelt
= 2
Supernova Cooling
Cosmic Diffuse -rays
Sne
Sne Cas A
Neutron Star
9
28
14
39
Matter Dominated Universe
Neutron Star Heat Excess
85
700
3
4
5
0.66 0.01
1.65
1.2
2.6
0.02
0.02
0.4
7
1.5
25
2.8
0.57
Low MD disfavored for  ≤ 3
* Can be evaded with hyperbolic manifolds
- Starkman, Stojkovic, Trodden
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
Black Hole event simulation @ LHC
Decay Properties of Black Holes (after Balding):
Decay proceeds by thermal emission of Hawking radiation
n determined to n = 0.75 @ 68% CL for n=2-6 from TH and 
This procedure doesn’t work for large n
At fixed MBH, higher dimensional BH’s are hotter:
N ~ 1/T
 higher dimensional BH’s
emit fewer quanta, with each
quanta having higher energy
Multiplicity for n = 2 to n = 6
Harris etal hep-ph/0411022
pT distributions of Black Hole decays
Provide good discriminating power for value of n
Generated using modified CHARYBDIS linked to PYTHIA
with M* = 1 TeV
Production rate is enormous!
Determination of Number
of Large Extra Dimensions
1 per sec at LHC!
JLH, Lillie, Rizzo
Primordial Microscopic Black Holes
• Produced in high-energy
collisions in early universe
• Rapid growth by absorption
of matter from surrounding
plasma
Empty Bulk
Excluded
Thermalized
Bulk
Mass density determined by TI
Demand:
1. Black Holes not overclose
the universe
2. Must not dominate energy
density during BBN
Conley, Wizansky
Universal Extra Dimensions
Appelquist, Cheng, Dobrescu
• All SM fields in TeV-1, 5d, S1/Z2 bulk
• No branes!  translational invariance is preserved
 tree-level conservation of p5
• KK number conserved at tree-level
broken at higher order by boundary terms
• KK parity conserved to all orders, (-1)n
Consequences:
1. KK excitations only produced in pairs
Relaxation of collider & precision EW constraints
Rc-1 ≥ 300 GeV!
2. Lightest KK particle is stable (LKP) and is Dark Matter
candidate
3. Boundary terms separate masses and give SUSY-like
spectrum
Universal Extra Dimensions: Bosonic SUSY
Phenomenology looks like
Supersymmetry:
Spectrum looks like SUSY !
Heavier KK particles cascade
down to LKP
LKP: Photon KK state
appears as missing ET
SUSY-like Spectroscopy
Confusion with SUSY if
discovered @ LHC !
Chang, Matchev,Schmaltz
How to distinguish SUSY from UED I:
Observe KK states in e+eannihilation
Measure their spin via:
•Threshold production, s-wave
vs p-wave
•Distribution of decay products
•However, could require CLIC
energies...
JLH, Rizzo, Tait
Datta, Kong, Matchev
How to distinguish SUSY from UED II:
Observe higher level (n = 2) KK
states:
– Pair production of q2q2, q2g2,
V2 V2
– Single production of V2 via
(1) small KK number
breaking couplings and (2)
from cascade decays of q2
Discovery reach @ LHC
Datta, Kong, Matchev
How to distinguish SUSY from UED III:
Measure the spins of the KK states @ LHC – Difficult!
Decay chains in SUSY and UED:
Form charge asymmetry:
Works for some,
but not all,
regions of
parameter space
Smillie, Webber
Identity of the LKP
• Boundary terms (similar to SUSY soft-masses)
– Induced @ loop-level (vanish @ cut-off)
– Determine masses & couplings of entire KK tower
• 1 ≪ 2 ≪ 3
– Smallest corrections to U(1) KK state
– NLKP is eR(1)
• M ~ 1/R > v
– LKP is almost pure Bino KK B(1)
Bino-Wino mass matrix, n=1
Thermal Production and Freeze Out
• Assume LKP in thermal
equilibrium in early universe
• Falls out of equilibrium as
universe expands
• Below freeze-out, density of LKP
WIMPS per co-moving volume is
fixed
For 1 TeV KK, Tf = 40 TeV
Co-annihilation
• eR(1) may substantially affect relic density if it is
close in mass to B(1)
• eR(1) has same interaction efficiency
– freeze-out temp is unaffected
• eR(1) left after freeze-out
– Eventually eR(1)  e(0) + B(1)
• Net relic density of B(1) is increased
Relic Density
…
 = scaled mass splitting
between eR(1) and B(1)
 = 0.05
 = 0.01
1 flavor
…
5 flavors
B(1) alone
h2 = 0.11  0.006 yields
for R:
5d range of 600-900 GeV
6d range of 425-625 GeV
Tait, Servant
More Complete Calculations
WMAP
 = 0.01 solid
0.05 dashed
Quasi-degenerate KK eL(1)
Kong, Matchev
Quasi-degenerate KK
quarks and gluons
Burnell, Kribs
Add Gravity in the Bulk
mG1 > mB1
KK graviton decays into B(1)
(mWG = KK scale from relic density
without graviton)
Shah, Wagner
mG1 < mB1
Super-WIMPS!
Feng, Rajaraman, Takayama
Direct Detection of LKP
• LKP – nucleon scattering:
Tait, Servant
Localized Gravity: Warped Extra Dimensions
Randall, Sundrum
Bulk = Slice of AdS5
5 = -24M53k2
k = curvature scale
Naturally stablized via Goldberger-Wise
Hierarchy is generated by exponential!
Kaluza-Klein Modes in a Detector: SM
on the brane
Number of Events in Drell-Yan @ LHC
For this same model
embedded in a string
theory: AdS5 x S
Unequal spacing signals curved space
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 @ LHC
gg  Gn  ZZ @ LHC
Lillie, Randall, Wang
Agashe, Davoudiasl, Perez, Soni
Issue: Top Collimation
g1 = 2 TeV
gg  gn  tt
g1 = 4 TeV
Lillie, Randall, Wang
Warped Extra Dimension with SO(10) in the bulk
• Splits families amongst 16
of SO(10) with different Z3
charges: Baryon symmetry in
bulk
• Lightest Z-odd particle, R’
KK state, is stable
Bold-face particles have
zero-modes
Gives correct relic
density for wide range
of masses
Agashe, Servant
Cosmic Ray Sensitivity to Black Hole Production
No suppression
Ringwald, Tu
Anchordoqui etal
Summary of Exp’t Constraints on MD
Anchordoqui, Feng
Goldberg, Shapere