Chinese-Led Team Discovers Heaviest Antimatter Hypernucleus to Date
A joint team of Chinese and international physicists has observed a new antimatter hypernucleus, marking a significant advancement in antimatter research. The discovery of anti-hyperhydrogen-4—the heaviest antimatter hypernucleus detected so far—was achieved using a heavy ion collider in the United States.
The groundbreaking research was led by the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences and was recently published in the prestigious journal Nature.
Unveiling the Mysteries of the Universe
According to current physics theories, matter and antimatter were created in equal amounts during the birth of the universe, and their properties are symmetrical. However, due to an unknown physical mechanism, a slight asymmetry occurred, leaving approximately one in ten billion matter particles after the annihilation of matter and antimatter. These surviving particles formed the universe as we know it today.
“What caused the difference in quantities of matter and antimatter in the universe? To answer this question, an important approach is to create new antimatter in the laboratory and study its properties,” explained Qiu Hao, a researcher at IMP.
The Challenge of Producing Antimatter
In our matter-dominated world, antimatter is exceedingly rare because it annihilates upon contact with matter. Antimatter nuclei and antimatter hypernuclei are even more challenging to produce. Since the theoretical prediction of antimatter’s existence in 1928, only six types of antimatter (hyper) nuclei have been discovered.
The newly discovered anti-hyperhydrogen-4 was produced at the Relativistic Heavy Ion Collider (RHIC) in the United States. RHIC accelerates heavy ion beams to nearly the speed of light, causing them to collide. These collisions recreate conditions similar to those just after the Big Bang, generating fireballs with temperatures reaching several trillion degrees and containing nearly equal amounts of matter and antimatter.
As the fireball rapidly expands and cools, some antimatter particles escape annihilation and are detected by the Solenoidal Tracker at RHIC (STAR) detector.
Reconstructing a Rare Antimatter Hypernucleus
“After analyzing experimental data from approximately 6.6 billion heavy-ion collision events, we reconstructed anti-hyperhydrogen-4 from its decay products,” said Wu Junlin, a PhD student at IMP.
The team also measured the lifetime of anti-hyperhydrogen-4 and found it to be consistent with that of its matter counterpart, hyperhydrogen-4, within the measurement precision. This finding further verifies the symmetry between matter and antimatter properties.
Implications for Future Research
This discovery represents a significant step forward in understanding the fundamental asymmetry between matter and antimatter in the universe. By studying antimatter hypernuclei, scientists hope to uncover the reasons behind the dominance of matter over antimatter and gain deeper insights into the origins and evolution of the cosmos.
Reference(s):
Breakthrough: China-led team makes new discovery in antimatter
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