A new discovery sheds light on the geneses of matter in the early universe

The early cosmos was 250,000 times hotter than the core of our sun. That’s far too hot to form the neutrons and protons that make up everyday matter. Researchers recreate the conditions of the early cosmos in particle accelerators by smashing atoms together at nearly the speed of light. Measuring the ensuing shower of particles allows researchers to understand how matter formed. The particles measured by the researchers can form in several ways: from the original soup of gluons and quarks or from later reactions.

These later reactions began 0.000001 seconds post the Big Bang, when the composite particles made of quarks started to interact with each other. A fresh calculation determined that as much as 70% of some measured particles are from these later reactions, not from reactions akin to those of the early cosmos. The research is published in Physics Letters B journal. This finding advances scientific understanding of the origins of matter. It helps ascertain how much of the matter around us formed in the first few fractions of a second after the Big Bang, versus how much matter formed from later reactions as the cosmos expanded.

This result implies large quantities of the matter around us formed later than anticipated. To appreciate the results of collider experiments, researchers must discount the particles formed in the later reactions. Only those formed in the subatomic soup disclose the early conditions of the cosmos. This new calculation indicates that the number of measured particles formed in reactions is much higher than anticipated.

In the 1990s, physicists gathered that certain particles form in substantial numbers from the later reactions subsequent to the initial formation phase of the cosmos. Particles termed D mesons can interact to form a rare particle, charmonium. Researchers lacked consensus on how significant the effect is. Since charmonium is rare, it is hard to measure. Nonetheless, recent experiments provide data on how many charmonium and D mesons colliders yield.

Physicists from Duke University and Yale University used the fresh data to calculate the power of this effect. It turns out to be far more substantial than expected. More than 70% of charmonium measured could be in fact formed in reactions. As the hot soup of subatomic particles cools down, it expands in a ball of fire. This all transpires in less than one hundredth of the time it takes for light to cross an atom. Since this is so fast, researchers are not sure exactly how the fireball expands.

The fresh calculation shows that researchers do not absolutely require to know the details of this expansion. The collisions yield a substantial amount of charmonium regardless. The fresh result brings scientists one step closer to understanding the origins of matter.