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

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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

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· 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