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Theoretical Issues in Astro Particle Physics
J.W. van Holten
April 26, 2004
The solar system is made
from quarks (baryons) and
leptons, interacting via
weak, electro-magnetic and
strong color forces.
This are the only forms of
matter we have been able
to create in accelerators at
energies up 1 TeV
The dominant contribution
to the mass of the universe
apparently comes from
other forms of matter.
Neutrino masses
See-saw mechanism:
large Majorana mass-scale M + Higss-induced Dirac
masses m generates large neutrino hierarchy:
(
0 m
m M
)
with M ~ 10
2
2
m = ½M ± ½(M +4 m )
_ M or m2/M = m m
~
M
6-8
GeV
2
-3
Δm ~ 10 eV
2
(Superkamiokande, SNO)
Accelerator physics
Extrapolation of running
gauge couplings of
standard model
M
Extrapolation of gauge
couplings in the MSSM
with TeV-scale
supersymmetry breaking
GUT
~ 10
16
GeV
Supersymmetry and MSSM
- All gauge and Higgs bosons have spin-1/2 partners
- All quarks and leptons have spin-0 partners
- The known MSM particles are distinguished from their
superpartners by a new quantum number: R-parity
- R-parity conservation a lightest superpartner stable
- LSP candidate:
neutralino χ: partner of photon / Z-boson / Higgs boson
gravitino ψ: partner of graviton
Rotational velocities
of stars in galaxies
deviation from
Kepler motion
Dark matter
WMAP survey of
Cosmic Microwave
Background
· flat universe
· ~ 5 % baryonic matter
· ~ 25 % non-baryonic matter
· ~ 70 % dark energy
• Neutralinos have standard weak interactions
• χ – p cross-sections
10 -11 pb < σ < 10-7 pb
for
100 GeV < m χ < 400 GeV
(Ellis et al., 2003)
• can accumulate in compact objects (stars, planets)
• can annihilate to produce neutrinos
New phases of matter
QCD changes collective behaviour of quarks and gluons
at high temperature and/or density:
- deconfinement: quarks become free
- chiral symmetry restoration: quarks become massless
- color superconductivity:
• BCS-type quark pairing
• massive gluons
(M. Alford)
New phases of matter
· Heavy-ion colliders:
QGP, color glass condensate
· compact cosmic objects:
neutron stars, strange stars,
quark stars (?)
neutron matter, strange matter,
color superconductivity
reflected in equation of state
(mass-radius relation)
Cosmic accelerators
20
Highest-energy cosmics: E = 3 x 10 eV
On collision with an oxygen nucleus:
6
s = 3 x 10 GeV
· Accelerating mechanism?
· Travel through intergalactic
space?
GKZ cut-off
· Dynamics of interaction:
quark-gluon plasma?
HiSPARC Nijmegen (NAHSA) has recorded the
highest-energy event ever observed in the
Netherlands: ~ 0.3 J / nucleon
Compact and hot early
universe:
· window on ultra-short
distance physics
· unification of gauge
interactions
· long-range scalar fields
(inflation, quintessence)
· quantum gravity,
gravitational waves