Dark Matter Search: LUX-ZEPLIN Experiment and Neutrino Fog

Why in the news?

Scientists from the LUX-ZEPLIN (LZ) experiment have placed the tightest restrictions yet on the identity of dark matter particles, marking a significant development in dark matter research despite not identifying the particle directly.

Dark Matter Search: LUX-ZEPLIN Experiment and Neutrino FogWhat is Dark Matter?

  • Composed of particles without charge, making them “dark” as they don’t emit light.
  • Makes up about 27% of the universe, interacting through gravity but not other fundamental forces like electromagnetism.
  • Invisible but inferred from gravitational effects on visible matter.
  • Comprises 95% of the universe along with dark energy; only 5% is visible matter.
  • Difficult to detect due to weak gravitational interaction.

What is Dark Energy?

  • A hypothetical form of energy that exerts a negative, repulsive force.
  • Explains the accelerated expansion of the universe observed in distant
  • Dark energy accounts for 68% of the universe, inferred from gravitational interactions, not directly observed..

Differences Between Dark Matter and Dark Energy

  • Dark matter: An attractive force that binds galaxies; interacts with gravity.
  • Dark energy: A repulsive force causing the universe to expand faster.
  • Dark energy makes up 68% of the universe, dark matter 27%, and visible matter only 5%.

Neutrinos:

  • Definition: Subatomic particles with no electric charge, small mass, and left-handed spin.
  • Neutrinos are too light to detect dark matter; other particles like Z boson companions have been proposed, but none are yet detected.
  • Abundance: Second-most abundant particles in the universe after photons; most abundant matter particles.
  • Interactions: Rarely interact with matter, making them challenging to study.
  • Neutrino Oscillation: Ability to change types (electron, muon, tau) while travelling.
  • Information Transmission: Potential to transmit information across large distances, possibly replacing electromagnetic waves.
  • Detection: Large, sensitive detectors built to maximise neutrino interactions.
  • India’s Project: Proposed Neutrino Observatory in Theni, Tamil Nadu, to be located in a 1,200-metre-deep cave.

Sources Referred:

PIB, The Hindu, Indian Express, Hindustan Times