Dr. Ralf Rapp discusses the origin of 98% of the visible mass in the universe in a recent article in Nature Physics. This mass was generated when a hot plasma of quarks and gluons condensed into hadrons in the early Universe. Calculations by Dr. Rapp and collaborators found that the mass of the rho-meson (a bound state of a quark and anti-quark) melts when this plasma is recreated in the lab in high-energy collisions of nuclei. This effect has now also been observed at lower collision energies, under conditions similar to those in mergers of neutron stars.
Read the full article here: https://www.nature.com/articles/s41567-019-0614-5