Strangeon Matter: From Stars to Nuggets

The fact that strange sea quarks are abundant in the nucleons, but with zero net strangeness, is of great importance for understanding the nature of matter condensed by strong interaction, particularly in the context of the “gigantic nucleus” created after the gravitational collapse of an evolved massive star. We hypothesize that the basic unit of bulk strong matter with the approximately light-flavored symmetry of valence quarks is “strangeon”, which is the counterpart of the nucleon found in atomic nuclei. In addition to strangeon stars (SnSs) with a large baryon number of A≈1057, strange nuggets (SnNs) with A≳1010 could also exist in the universe. Both the SnSs and the SnNs are explained, with particular focus on the evidence obtained from observation and detection.