From Little Bangs to the Big Bang

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From Little Bangs to the Big Bang

• ICPAQGP, Kolkata, Feb. 8th, 2005
• John Ellis

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The Universe so far
time
space
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The Universe is expanding

• Galaxies are receding from us
• Hubble expansion law galactic redshifts
• The Universe was once 3000 smaller, hotter than
  today
• cosmic microwave background radiation

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Cosmic Microwave Background
Almost the same in different directions ?
Small variations discovered by COBE satellite ?
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The Universe is expanding

• Galaxies are receding from us
• Hubble expansion law galactic redshifts
• The Universe was once 3000 smaller, hotter than
  today
• cosmic microwave background radiation
• The Universe was once a billion times smaller,
  hotter than today
• light elements cooked in the Big Bang

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Big-Bang Nucleosynthesis

• Universe contains about 24 Helium 4
• and less Deuterium, Helium 3, Lithium 7
• Could only have been cooked by nuclear reactions
  in dense early Universe
• when Universe billion times smaller, hotter
  than today
• Dependent on amount of matter in Universe
• not enough to stop expansion, explain galaxies
• Dependent on number of particle types
• number of different neutrinos measured at
  accelerators

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Abundances of light elements in the Universe
Helium
? Agree with data
Theoretical calculations ?
Lithium
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The Very Early Universe
QGP

• Size a ? zero
• Age t ? zero
• Temperature T ? large
• T 1/a, t 1/T2
• Energies E T
• Rough magnitudes
• T 10,000,000,000 degrees
• E 1 MeV mass of electron
• t 1 second

Need particle physics to describe earlier history
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Hot and Dense Hadronic Matter
QGP
Recreate the first 10-6 seconds
and probe the quark-hadron phase transition
LHC
LHC
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The Quark-Gluon Transition?
QGP

• Not a strong first-order transition
• Probably a cross-over
• Not expected to induce large inhomogeneities

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Open Cosmological Questions

• Why is the Universe so big and old?
• 13,000,000,000 years
• Why is its geometry nearly Euclidean?
• almost flat, borderline for eternal expansion
• Where did the matter come from?
• 1 proton for every 1,000,000,000 photons
• How did structures form?
• ripples invisible dark matter?
• What is the dark matter?

Need particle physics to answer these questions
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A Strange Recipe for a Universe
The Concordance Model prompted by astrophysics
cosmology
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The Density Budget of the Universe

• Total density critical
• Theory of inflation, measurements of CMB
  OTot 1
• Baryon density small
• Big-bang nucleosynthesis, CMB
• OBaryons few

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The CosmicMicrowaveBackground
According to COBE
According to WMAP - at one frequency
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The CMB according to WMAP
Combining different frequencies
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The CMB Power Spectrum
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WMAP Constraints on Density
Dark energy
Matter
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Abundances of light elements in the Universe
Helium
? Agree with data
Theoretical calculations ?
Lithium
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Scope forInhomogeneousNucleosynthesis?
QGP

• Inhomogeneities
• generated at QCD
• phase transition?
• Would need to be
• strongly first-order
• Constrained by CMB,
• measured abundances

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Generating the matter in the Universe
Sakharov

• Need difference between matter, antimatter
• charge symmetry broken in laboratory
• Need matter-creating interactions
• present in unified theories not yet seen
• Need breakdown of thermal equilibrium
• possible during phase transition (GUT, SM?)
• in decays of heavy particles (singlet ?R?)

Can we calculate from laboratory measurements?
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The Density Budget of the Universe

• Total density critical
• Theory of inflation, measurements of CMB
  OTot 1
• Baryon density small
• Big-bang nucleosynthesis, CMB
• OBaryons few
• Total matter density much larger
• Clusters of galaxies
• OMatter 25
• Mainly cold dark matter
• Enables structure formation

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Formation of Structures in Universe

• Develop from CMB fluctuations
• Need amplification
• Possible with massive weakly-interacting
  particles
• Light neutrinos escape from smaller structures ?
  disfavoured
• Prefer non-relativistic cold dark matter

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Structures observed in the Universe
Galaxies ? Clusters ? smooth at largest scales
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Structures in Universe vs Concordance Model
Flat Universe OTot 1, Cold dark matter OCDM
0.25, No hot dark matter, Few baryons Ob
0.05, Dark energy O? 0.7
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Do Neutrinos matter?

• Have very small masses
• but non-zero oscillation experiments
• Might make up some of dark matter
• less than 10?
• And would escape from galaxies
• moving relativistically
• Also heavier neutrinos?
• but unstable generate matter via Sakharov?
• Need heavier stable dark matter particles
• supersymmetric particles?

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Not much neutrino mass density
2dF team astro-ph/0204152
Data on large-scale structures
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Not much Hot (Neutrino) Dark Matter
According to WMAP et al
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Baryonic Ripples from the Big Bang
Hot news

• Sound waves spread from CMB bumps

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Observations of Baryonic Ripples
Confirm Cold Dark Matter constrain parameters
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Particle Dark Matter Candidates
A A A A A A A A A A A A A A A a
Cold thermal relics, e.g., LSP
Superheavy cryptons
axion
gravitino
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Supersymmetric Dark Matter?

• Supersymmetry would relate
• fermionic matter particles ?
• bosonic force particles
• Might help explain mass scale of particles
• Lightest supersymmetric particle stable?
• should weigh below 1000 GeV
• Density similar to required cold dark matter

Directly laboratory searches, indirect
astrophysical searches
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Minimal Supersymmetric Extension of Standard
Model (MSSM)

• Particles spartners 2 Higgs doublets
• Soft supersymmetry-breaking parameters
• Scalar masses m0, gaugino masses m1/2,
  trilinear soft couplings A?
• Often assume universality
• Single m0, single m1/2, single A?
• Called constrained MSSM CMSSM
• Gravitino mass?
• m3/2 m0 in minimal supergravity

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Lightest Supersymmetric Particle

• Stable in many models because of conservation of
  R parity
• R (-1) 2S L 3B
• where S spin, L lepton , B baryon
• Particles have R 1, sparticles R -1
• Sparticles produced in pairs
• Heavier sparticles ? lighter sparticles
• Lightest supersymmetric particle (LSP) stable

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Possible Nature of LSP

• No strong or electromagnetic interactions
• Otherwise would bind to matter
• Detectable as anomalous heavy nucleus
• Possible weakly-interacting scandidates
• Sneutrino
• (Excluded by LEP, direct searches)
• Lightest neutralino ?
• Gravitino
• (nightmare for detection)

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Constraints on Supersymmetry

• Absence of sparticles at LEP, Tevatron
• selectron, chargino gt 100 GeV
• squarks, gluino gt 250 GeV
• Indirect constraints
• Higgs gt 114 GeV, b -gt s ?
• Density of dark matter
• lightest sparticle ?
• WMAP 0.094 lt O?h2 lt 0.124

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QGP
Relic Density and Quark-Gluon Plasma

• Relic density depends on
• Hubble expansion rate
• Sensitive to effective particles
• where
• Need to understand hot QCD

Hindmarsh Philipsen
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Current Constraints on CMSSM
Excluded because stau LSP
Excluded by b ? s gamma
WMAP constraint on relic density
Excluded (?) by latest g - 2
Latest CDF/D0 top mass
JE Olive Santoso Spanos
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Supersymmetry Searches at LHC
LHC reach in supersymmetric parameter
space Covers most of cosmological region
Typical supersymmetric Event at the LHC Easy
to see
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Strategies for Detecting Supersymmetric Dark
Matter

• Annihilation in galactic halo
• ? ? ? antiprotons, positrons, ?
• Annihilation in galactic centre
• ? ? ? ? ?
• Annihilation in core of Sun or Earth
• ? ? ? ? ? µ
• Scattering on nucleus in laboratory
• ? A ? ? A

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Annihilation in Galactic Halo
Antiprotons
Consistent with production by primary matter
cosmic rays
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Annihilations in Galactic Centre
Benchmark spectra
Benchmarks ? GLAST
Enhancement of rate uncertain by factor gt 100!
JE Feng Matchev Olive
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Annihilations in Solar System
Sun
Earth
Prospective experimental sensitivities
Benchmark scenarios
JE Feng Matchev Olive
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Elastic Scattering Cross Sections
From global fit to accelerator data
Latest experimental upper limit
JE Olive Santoso Spanos hep-ph/0502001
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Big Bang ? Little Bangs

• The matter content of the Universe
• Dark matter
• Dark energy
• Origin of matter

• Experiments at particle colliders
• Early Universe
• Supersymmetry
• Matter-antimattter asymmetry

Learn particle physics from the Universe Use
particle physics to understand the Universe
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The Density Budget of the Universe

• Total density critical
• Theory of inflation, measurements of CMB OTot
  1
• Baryon density small
• Big-bang nucleosynthesis, CMB OBaryons few
  
• Total matter density much larger
• Clusters of galaxies OMatter 25
• Mainly cold dark matter
• Enable structure formation
• Most of density is dark energy
• Supported by high-redshift supernovae

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How do Matter and Antimatter Differ?
Matter and antimatter not quite equal and
opposite WHY?
Why does the Universe mainly contain matter, not
antimatter?
Experiments at LHC and elsewhere looking for
answers
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High-redshift supernovae are standard candles
Riess et al, Perlmutter et al
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Supernovae prefer Large OTot Small OMatter
Dark energy density constant W -1
Riess et al, Perlmutter et al
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Astronomers say that most of the matter in
the Universe is invisible Dark Matter
Supersymmetric particles ?
We shall look for them with the LHC
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Our Halo is not made of Machos
Could our galactic halo be baryonic?
MAssive Compact Halo Objects
lt 10 of our halo
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Why Supersymmetry (Susy)?

• Hierarchy problem why is mW ltlt mP ?
• (mP 1019 GeV is scale of gravity)
• Alternatively, why is
• GF 1/ mW2 gtgt GN 1/mP2 ?
• Or, why is
• VCoulomb gtgt VNewton ? e2 gtgt G m2 m2 / mP2
• Set by hand? What about loop corrections?
• dmH,W2 O(a/p) ?2
• Cancel boson loops ? fermions
• Need mB2 mF2 lt 1 TeV2

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Other Reasons to like Susy
It enables the gauge couplings to unify
Approved by Fabiola Gianotti
Amaldi de Boer Furstenau, Langacker Luo, JE
Kelley Nanopoulos
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Current Constraints on CMSSM
Different tan ß sign of µ
Impact of Higgs constraint reduced if larger mt,
focus-point region far up
JE Olive Santoso Spanos
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Supersymmetric Benchmark Studies
Lines in susy space allowed by accelerators, WMAP
data
Specific benchmark Points along WMAP lines
Sparticle Detectability _at_ LHC along one WMAP line
LHC enables calculation of relic density at a
benchmark point
Can be refined with LC measurements
Battaglia et al
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Annihilations in Solar System
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Direct Detection of Supersymmetric Dark Matter
Effective Lagrangian for ? q scattering
Spin-independent depend on quark contributions
to baryon mass
Spin-dependent depend on quark contributions to
baryon spin
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Cross Sections depend on p-N s Term
Specific benchmark scenarios
Survey of parameter plane
JE Olive Santoso Spanos hep-ph/0502001
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Very Few CMSSM Scenarios Excluded
JE Olive Santoso Spanos
JE Olive Santoso Spanos hep-ph/0502001
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A Few Less Specific Models Excluded
For special values of parameters
JE Olive Santoso Spanos hep-ph/0502001
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Spin-Independent Scattering Cross Section
DAMA
Experimental limits ?? other susy models
Comparison with our calculations
CDMS II
JE Olive Santoso Spanos
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Superheavy Dark Matter

• Could have been produced non-thermally during the
  very early Universe
• During inflation? Gravitationally?
• Natural candidates in some string models
• Metastable bound states of superstrong hidden
  interactions Cryptons
• Neutral cryptons with lifetimes gt 1010 years

Decays ? ultra-high-energy cosmic rays ?
JE Lopez Nanopoulos, Benakli JE
Nanopoulos, JE Mayes Nanopoulos
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Fit to UHECRs with Crypton Decays
Naïve extrapolation
Sarkar Toldra
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Scattering Cross Sections in Benchmark Scenarios
Spin-dependent
Spin-independent
Compared with possible future experimental
sensitivities
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DifferentRegions of SparticleParameterSpace
ifGravitino LSP
Density below WMAP limit
Decays do not affect BBN/CMB agreement
JE Olive Santoso Spanos
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Minimal Supergravity Model
m0 m3/2
Excluded by b ? s ?
LEP constraints On mh, chargino
JE Olive Santoso Spanos
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Cosmic-Ray Spectrum
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Difficult to Explain with Conventional
Astrophysical Sources?
Required size and magnetic field
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Signatures of Mechanisms for UHECRs
Correlations in arrival directions from discrete
astrophysical sources?
Anisotropies from cryptons in galactic halo?
Macrophysics or microphysics ?
Sarkar
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Comments on Dark Energy

• Many orders of magnitude smaller than expected
  contributions from known physics 10-48 GeV4
• QCD ?QCD4 10-4 GeV4
• Higgs mW4 108 GeV4
• Broken susy msusy4 1012 GeV4
• GUT mGUT4 1064 GeV4
• Quantum Gravity mP4 1076 GeV4
• Need new physics!

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Theorists devoting their Branes to the Problem
- Maybe we live on a subspace in some
higher-dimensional Universe (brane) populated
also by other branes? - Maybe branes still
moving apart? - We would feel apparent dark
energy rate of separation
JE Mavromatos Westmuckett
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Physics of the Microwave Background
Curvature
Acoustic Oscillations
Damping
Doppler
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Cooking the Light Elements

• Universe contains about 24 Helium
• and less Lithium
• Could only have been cooked by nuclear reactions
  in dense early Universe
• when Universe billion times smaller, hotter
  than today
• Depends on amount of matter in Universe
• not enough to stop expansion, explain galaxies
• Depends on number of particle types
• measured at accelerators

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Hubble Expansion Law

• Light from distant galaxies is redder
• Effect proportional to distance
• Light waves expand as Universe grows
• Separation speeds
• 70 km/second/million light-years
• Most distant visible objects about
• 10,000,000,000 light-years away
• Same physics as us!

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Cosmic Microwave Background

• We are bathed in microwave radiation
• at 3 degrees above absolute zero
• Almost the same in all directions
• we are moving at about 700 km/second
• Small ripples in the microwave background
• one part in 100,000
• Probably originated in very young Universe
• 0.000,000,000,000,000,000,000,000,000,000,000,
  001 seconds old?

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The story before WMAP
Dec02, Jan03
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How Likely are Large Sparticle Masses?
Fine-tuning of EW scale
Fine-tuning of relic density
Larger masses require more fine-tuning but how
much is too much?
JE Olive Santoso Spanos
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LHC and LCScapabilities
LHC almost guaranteed to discover supersymmetry
if it is relevant to the mass problem
LC oberves complementary sparticles
Battaglia et al
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