Gluons may play a central role in baryon number conservation—and matter's stability

New observations from the STAR detector at the Relativistic Heavy Ion Collider (RHIC) indicate that gluons, the particles responsible for binding quarks within protons, may be the core carriers of baryon number—an essential aspect of a particle's quantum identity. Baryon number conservation, which maintains the total number of baryons (particles composed of three quarks) before and after high-energy collisions, has been a cornerstone of particle physics for decades.

However, the recent findings from RHIC suggest that baryon number may be carried by a unique configuration of gluons, challenging the long-standing belief that it is solely carried by the three valence quarks within a proton.

Traditionally, scientists have assumed that each of the three valence quarks in a proton carries one-third of the baryon number. This assumption was based on the idea that the baryon number is carried by individual quarks. However, the STAR team at RHIC has proposed a new perspective. The team's research, published in the journal Science, supports the notion that baryon number is more effectively carried and transported by gluons when they form a specific Y-shaped junction connecting the three main quarks.

The STAR collaboration, comprising physicists from various institutions, utilized data collected from collisions at RHIC to test this idea. By comparing the net baryon numbers observed from different types of particle collisions with the redistribution of electric charges in the same collisions, the researchers found compelling evidence that supports the gluon-centric model of baryon number conservation.

The findings suggest that the traditional quark-centric view of baryon number carries may not be entirely accurate, and that gluons play a more significant role than previously thought.

The implications of this discovery are far-reaching. Understanding the true carrier of baryon number is crucial for explaining fundamental properties of matter, such as the stability of protons, which is believed to be longer than the age of the universe. Matter, as we know it, is composed of stable atomic nuclei formed through baryon number conservation. Moreover, the new insights into gluon behavior could help resolve the longstanding mystery of why the universe contains more matter than antimatter.

The STAR team's innovative approach to testing the gluon-centric model involved analyzing the distribution of electric charges in the collisions. By comparing the net baryon numbers observed from various nuclear smashups at RHIC with the redistribution of electric charges, the researchers were able to determine the extent to which gluons are responsible for carrying baryon number.

The results consistently showed a strong preference for the gluon-centric model, providing compelling evidence that challenges the conventional understanding of baryon number conservation.