Physics

Choose the Correct Answer

Correct Answer : Option c

Explanation
Recently, China’s Jiangmen Underground Neutrino Observatory (JUNO) began its data collection phase to study neutrinos, marking a major milestone in global particle physics research.

Statement 1 is correct: The Jiangmen Underground Neutrino Observatory (JUNO), located in Kaiping, Jiangmen City, Guangdong Province, China, is designed to be the world’s largest liquid scintillator neutrino detector. It features a 20,000-ton spherical chamber filled with liquid scintillator, enabling it to detect neutrinos with exceptional precision. Owing to its massive size and advanced design, JUNO can effectively capture neutrinos originating from nuclear reactors and cosmic sources, contributing significantly to research on neutrino properties and fundamental particle physics.

Statement 2 is correct: One of JUNO’s key scientific goals is to determine the neutrino mass ordering (or mass hierarchy), that is, whether the three neutrino mass states follow a normal or inverted arrangement. Resolving this question is vital for deepening our understanding of particle physics and the role of neutrinos in the evolution of the universe. To achieve this, JUNO detects antineutrinos emitted from the Taishan and Yangjiang nuclear power plants, located about 53 km away, allowing it to precisely measure neutrino oscillation parameters and determine the mass hierarchy with high accuracy and sensitivity.

Statement 3 is not correct: Neutrinos are notoriously difficult to detect because they interact extremely weakly with matter, engaging only through the weak nuclear force and gravity, while remaining unaffected by electromagnetic or strong nuclear forces. Being electrically neutral, almost massless, and capable of passing through entire planets without interaction, they are often called “ghost particles.” This elusive nature necessitates massive, underground detectors like JUNO, which are designed to maximize the chances of capturing rare neutrino interactions while being shielded from cosmic rays and background radiation, ensuring highly sensitive and accurate observations