Nuclear Matter from an Effective Lattice Theory of QCD
Owe Philipsen (ITP, Goethe-Universität, Frankfurt/Main)

Despite the long history of experimental nuclear physics and a plethora of data, we are still lacking a theoretical description in terms of the fundamental theory of the strong interactions, Quantum Chromodynamics (QCD).
This issue has become pressing with the discovery of very massive neutron stars, whose core density is believed to exceed nuclear density by far, and hence warrants a theoretical description of bulk nuclear matter rooted in QCD.
Unfortunately, QCD at finite matter density is not tractable by lattice Monte Carlo methods, which have proven so successful in the theoretical description of the hadron spectrum. After a brief introduction to lattice QCD, I will explain why it does not work at finite density and summarize what we know about the QCD phase diagram. I will then present a solution to the problem based on analytic expansions, which are so far only valid for very heavy quarks. For this case, an equation of state for bulk nuclear matter can be successfully calculated.