About Neutrinos

• Neutrinos are subatomic particles, similar to electrons but without an electric charge.
  • Neutrinos are the 2nd most abundant particles in the universe after Photons.
• Approximately a billion neutrinos pass through a cubic centimetre of space every second.
• First detected in 1959, though their existence was theorized in 1931.
• High-energy neutrinos, which originate from exotic astrophysical events like supernovae, gamma-ray bursts, or colliding stars, are of particular interest to scientists because:
• Neutrinos can travel through dense cosmic environments, such as the dust-shrouded centre of the Milky Way, where visible light telescopes fail.
• Neutrino detection depends on observing Cherenkov radiation — light flashes produced when neutrinos interact with water or ice molecules.
  • Darkness is essential for detecting the faint flashes of Cherenkov radiation.
• Why study neutrinos?
  • Neutrinos provide insights into particle physics, including neutrino oscillations and mass hierarchy, challenging the Standard Model.
  • Neutrinos pass through dense cosmic regions, offering access to areas invisible to traditional telescopes.
  • Studying neutrinos aids in tracing cosmic ray origins and understanding dark matter, unlocking mysteries of the universe.

PYQ:

[2010] India-based Neutrino Observatory is included by the planning commission as a mega-science project under the 11th Five-year plan. In this context, consider the following statements:

1. Neutrinos are chargeless elementary particles that travel close to the speed of light.
2. Neutrinos are created in nuclear reactions of beta decay.
3. Neutrinos have a negligible, but non-zero mass.
4. Trillions of Neutrinos pass through the human body every second.

Which of the statements given above are correct?

(a) 1 and 3 only

(b) 1, 2 and 3 only

(c) 2, 3 and 4

(d) 1, 2, 3 and 4