China races to unlock one of the biggest mysteries in particle physics
JUNO, the underground facility in Kaiping, will boot up in 2025.
China hopes a giant laboratory 2,300 feet underground is key to beating the US at discovering the secrets of the universe’s most mysterious particles–neutrinos.
Slated for completion next year, after over a decade of construction, the roughly $311 million Jiangmen Underground Neutrino Observatory (JUNO) relies on a nearly 115-foot-wide stainless steel and acrylic spherical machine designed to help measure incomprehensibly small subatomic units that move almost at the speed of light. Despite blanketing the universe (100 trillion are believed to pass through your body every second), very little is known about neutrinos and their behavior due how difficult it is to detect them.
The "mass hierarchy" problem is a fundamental challenge in particle physics that refers to the lack of knowledge about the masses of neutrinos, subatomic particles that are thought to occupy one of three mass states. Neutrinos are created in the cores of stars and in nuclear reactors, and they interact with matter through the weak nuclear force. However, their masses are still unknown, and this lack of knowledge has significant implications for our understanding of the universe.
To understand the mass hierarchy problem, it's essential to understand the basics of neutrinos and their behavior. Neutrinos are created when certain types of atomic nuclei undergo radioactive decay. They are extremely light, with masses that are typically measured in electronvolts (eV). However, neutrinos can also oscillate between different mass states, which means that their mass is not fixed and can vary over time.
There are three known mass states for neutrinos, which are denoted by the letters "e," "μ," and "τ." The "e" state is associated with electrons, the "μ" state with muons, and the "τ" state with tau particles. The problem is that we don't know which state corresponds to which mass.
One way to understand the mass hierarchy problem is to consider the behavior of neutrinos in the universe. Neutrinos are created in the cores of stars and in nuclear reactors, and they interact with matter through the weak nuclear force. However, their masses are still unknown, and this lack of knowledge has significant implications for our understanding of the universe.
For example, neutrinos are thought to play a crucial role in the formation and evolution of stars. The masses of neutrinos determine how they interact with matter, which in turn affects the way that stars form and evolve. However, without a complete understanding of the masses of neutrinos, we can't fully appreciate their role in the universe.
The mass hierarchy problem also has significant implications for our understanding of the fundamental laws of physics. The masses of neutrinos are closely tied to the Higgs boson, a particle that is responsible for giving other particles mass. The Higgs boson is a key component of the Standard Model of particle physics, which is the most comprehensive theory of particle physics that we have today. However, the masses of neutrinos are still unknown, and this lack of knowledge has significant implications for our understanding of the Higgs boson and the fundamental laws of physics.
The JUNO experiment is a cutting-edge neutrino detector that is designed to solve the mass hierarchy problem. The detector is located deep beneath the Earth, where it can detect the faint signals produced by neutrinos that interact with matter. The JUNO experiment uses a innovative design to detect neutrinos, which involves using a large, spherical detector that is filled with liquid scintillator.
The liquid scintillator is a special type of material that is designed to detect the faint signals produced by neutrinos. The scintillator is filled with a cocktail of organic compounds that are designed to absorb the energy produced by neutrinos. When a neutrino interacts with the scintillator, it produces a signal that is measured by the detector. The signal is then used to calculate the properties of the neutrino, including its mass.
The JUNO experiment is expected to provide a wealth of new information about the masses of neutrinos. By detecting thousands of neutrino events per second, the detector is able to determine the properties of the neutrinos with high precision. The experiment is also designed to detect the faint signals produced by neutrinos that interact with matter, which provides a unique opportunity to study the properties of the neutrinos in great detail.
The JUNO experiment is a significant step forward in the study of neutrinos and their properties. By solving the mass hierarchy problem, the experiment is expected to provide new insights into the fundamental laws of physics and the behavior of neutrinos in the universe. The results of the JUNO experiment are expected to be published in the coming years, and they are expected to have a significant impact on the field of particle physics.
In summary, the mass hierarchy problem is a fundamental challenge in particle physics that refers to the lack of knowledge about the masses of neutrinos. The JUNO experiment is a cutting-edge neutrino detector that is designed to solve the mass hierarchy problem. The detector uses a innovative design to detect neutrinos, which involves using a large, spherical detector that is filled with liquid scintillator. The experiment is expected to provide a wealth of new information about the masses of neutrinos and is a significant step forward in the study of neutrinos and their properties.
Here are some key points to consider:
Article