Matter at Extreme Densities

Neutron stars are very dense objects. One teaspoon of their material would have a mass of five billion tons. Their gravitational force is so strong that if an object were to fall from just one meter high, it would hit the surface of the respective neutron star at 2 thousand kilometers per second. In such dense bodies, different particles from the ones present in atomic nuclei, the nucleons, can exist. These particles are hyperons, that contain non-zero strangeness and, if the density is high enough to deconfine them, quarks.

Below, astronomical objects containing extremely dense matter are shown in the QCD phase diagram (pink bubbles). On the vertical axis is the temperature and on the horizontal axis is the chemical potential (or density) of matter. The grey bubbles exemplify the early universe and different environments created in the lab.