Exotic Phases of Matter in Compact Stars
Disk Galaxy NGC 4526 in Virgo
Supernova 1994D Fredrik Sandin [email protected] Outline • Introduction
• Colour superconducting quark matter in “neutron stars”
• Preon stars, a new class of compact stars in the cosmos?
2/ 16 Stars • Form in clouds of interstellar gas •Gravity Æ Pressure + heat Æ Fusion Æ Thermal pressure Æ Equilibrium
“Pressure = Gravity”
• Fusion Æ Heavy elements Æ Less “fuel” Æ ... Æ COLLAPSE
3/ 16 Compact Stars • The corpses of stars • Form when some stars collapse • Gravitational energy Æ Gigantic explosion (supernova)
• Three main types: Puppis A • White dwarfs ρ ∼ 107 g/cm3 • Neutron stars ρ ∼ 1015 g/cm3 • Black holes ρ ~ M/R3
ROSAT X-ray Observatory 4/ 16 The Composition of “Neutron Stars”
F. Weber, Prog. Part. Nucl. Phys. 54 (2005) p. 193 … is unknown
5/ 16 Conjectured Phase Diagram of Strongly Interacting Matter Early Universe
LHC (CERN) Quark-Gluon Plasma (QGP)
RHIC (BNL)
SPS (CERN) AGS (BNL) Supernovae SIS (GSI) Colour Superconductor Temperature (T) Hadron Gas
Vacuum (
µ Baryon chemical potential ( B)
6/ 16 Model of Quark Matter µ • Three flavours ( B/3 > Ms)
• Quark masses generated dynamically
• Attractive q-q interaction (colour 3 channel)
7/ 16 Model of Quark Matter (2) • Other important issues • Weak interactions (leptons included) • No gluon fields Æ No gluon condensates, 0 , 〈A a〉 that neutralize colour charges Æ Colour neutrality must be enforced • The parameters are fixed with experimental results, e.g., meson properties • Mean-field (Hartree) approximation + Imaginary-time formalism Æ Thermodynamic potential Æ
8/ 16 Phase Diagrams
Ex.
9/ 16 Quark/Hybrid Star Properties Ex.
Mass-Radius Relations Ex. Cooling Evolution
10 / 16 D e i s ns er ta t b of il ity
11 / 16 Preon Stars • Preons • Hypothetical building blocks of quarks, leptons and (some) gauge bosons
Molecule Atom Nucleus Proton Quark Preon
3000 BC 1811 1905 Time (Adam & Eve) 1911 1968 2007? • Some estimates indicate that preons, e.g., in massive quarks, are in-reach of the next generation of particle accelerators. Though, maybe not… • If preons exist, preon stars could exist J. Hansson & F. Sandin, Phys. Lett. B 616 (2005), pp. 1-7. F. Sandin, Eur. Phys. J. C 40 (2005), pp. 15-22. 12 / 16 13 / 16 Mass and Radius of Preon Stars • Can be estimated with several methods, e.g., • Chandrasekhar limit
• Schwarzschild radius
• In general: Jahre Viking 2 • M < ~10 MEarth • R < ~101 m 485 m
8 6.5 x 10 kg 14 / 16 Observation
J. Hansson & F. Sandin, to be submitted
GRB
Preon Star
Di st an ce ~ 1 0 10 light y ea Observable range: rs • One satellite: ~1014 < M < ~1017 kg • Two satellites: ~1014 < M < ~1024 kg 15 / 16 Work in Progress • Quark Matter 1. Constraint for gapless excitations 2. Influence of non-local form factors 3. Influence of hadronic crust (hybrid stars)
•PreonStars 4. Interpretation of absorption lines found in some GRB spectra 5. High-frequency gravitational waves from binaries (ÆR?)
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