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.
The dominant contribution to the mass of the universe apparently comes from other forms of matter.
This are the only forms of matter we have been able to create in accelerators at energies up 1 TeV
Neutrino masses
See-saw mechanism:
large Majorana mass-scale M + Higss-induced Dirac masses m generates large neutrino hierarchy:
( ) 0 m
m Mm = ½M ± ½(M +4 m )
~ M or m /M = m
2 2
_ 2
with M ~ 10 GeV Δm ~ 10 eV6-8 2 -3 2
(Superkamiokande, SNO)
mM
Extrapolation of running gauge couplings of standard model
Extrapolation of gauge couplings in the MSSM with TeV-scale supersymmetry breaking
Accelerator physics
M ~ 10 GeVGUT
16
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 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 pb < σ < 10 pb
for
100 GeV < m < 400 GeV
(Ellis et al., 2003)
• can accumulate in compact objects (stars, planets)
• can annihilate to produce neutrinos
χ
-11
-7
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)
· 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)
New phases of matter
Cosmic accelerators
Highest-energy cosmics: E = 3 x 10 eV
On collision with an oxygen nucleus:
s = 3 x 10 GeV
20
6
· 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
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