At the heart of a neutron star, matter is squeezed so tightly that protons and neutrons transform into heavier particles — hyperons. These particles resemble neutrons but contain a strange quark. For a long time, physicists couldn't understand how a star with hyperons inside could be as heavy as observations show.
This new study accounts for quantum effects that arise when particles interact strongly with each other. It's like passengers on a packed bus not just jostling but moving in sync, creating extra rigidity. Thanks to this, matter can withstand higher pressure, and the star can grow to 2.59 solar masses without falling apart.
This result explains why the heaviest neutron stars exist and why they don't cool too fast. In ordinary stars, hyperons and protons could trigger rapid cooling, but in the new model their fraction is small. So the star stays hot longer, matching observations.
Hyperons are particles that live less than one billionth of a second when free, but inside a neutron star they are stable due to immense pressure.