Space-Time Induces Neutrino Oscillations

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Indian scientists have shown that the geometry of space-time can cause neutrinos to oscillate.

Neutrinos

• Neutrinos are the smallest particles currently known.
• Since neutrinos are electrically neutral, they are not affected by the electromagnetic forces which act on electrons. Hence, they are also called Ghost Particles.
• Neutrinos are everywhere, but they interact so weakly with the forces around hence, are hard to detect.

Key Findings

• Neutrinos are mysterious particles, produced copiously in nuclear reactions in the Sun, stars, and elsewhere.
• They “oscillate”- meaning that different types of neutrinos change into one another – as has been found in many experiments.
• Probing of oscillations of neutrinos and their relations with mass are crucial in studying the origin of the universe.
• Neutrinos interact very weakly with everything else – trillions of them pass through every human being every second without anyone noticing.
• A neutrino’s spin always points in the opposite direction of its motion, and until a few years ago, neutrinos were believed to be massless.

Cause Neutrino Oscillations

• The geometry of space-time can cause neutrino oscillations through quantum effects even if neutrinos are massless.
• Einstein’s theory of general relativity says that gravitation is the manifestation of space-time curvature.
• Neutrinos, electrons, protons and other particles, which are in the category of fermions, show a certain peculiarity when they move in presence of gravity.
• Space-time induces a quantum force in addition to gravity between every two fermions.
• This force can depend on the spin of the particles, and causes massless neutrinos to appear massive when they pass through matter, like the Sun’s corona or the Earth’s atmosphere.
• Something similar happens for electroweak interactions, and together with the geometrically induced mass it is enough to cause oscillation of neutrinos.

Source: PIB