A simple atomic nucleus could reveal properties associated with the mysterious phenomenon known as time reversal and lead to an explanation for one of the greatest mysteries of physics: the imbalance of matter and antimatter in the universe.

The physics world was rocked recently by the news that a class of subatomic particles known as neutrinos may have broken the speed of light.

Adding to the rash of new ideas, University of Arizona theoretical physicist Bira van Kolck recently proposed that experiments with another small particle called a deuteron could lead to an explanation for one of the most daunting puzzles physicists face: the imbalance of matter and antimatter in the universe.

A deuteron is a simple atomic nucleus, or the core of an atom. Its simplicity makes it one of the best objects for experiments in nuclear physics.

A property of the deuteron known as a magnetic quadrupole moment could reveal sources of a phenomenon known as time reversal violation, Van Kolck and his collaborators, including recently graduated UA doctoral student Emanuele Mereghetti, show in a recent paper published in Physical Review Letters.

Most of what physicists know about the universe can be described by what is called the standard model of particle physics. Developed by Van Kolck’s former doctoral advisor, Nobel Laureate Steven Weinberg, the standard model describes everything from Newton’s laws of motion to the behavior of subatomic particles with what is known as quantum mechanics.

“This theory explains almost everything we know about the universe up to this point,” said Van Kolck. “However,” he added, “there is one problem that the standard model does not explain.”

“Like the protons and neutrons – the particles making up the nucleus of an atom – every particle has what’s called an antiparticle, things like antiprotons or antineutrons. The universe seems to have many more particles than antiparticles,” said Van Kolck. “So there is a question of why the universe seems to have such an asymmetry between particles and antiparticles.” (via Time reversal: A simple particle could reveal new physics)