Scientists have shown that the geometry of space-time can cause neutrinos to oscillate.
- Neutrinos are mysterious particles, produced copiously in nuclear reactions in the Sun, stars, and elsewhere.
- They also “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.
- It is now generally believed that the phenomenon of neutrino oscillations require neutrinos to have tiny masses.
Professor Amitabha Lahiri of S N Bose National Centre for Basic Sciences (SNBNCBS) an autonomous institute under the Department of Science & Technology (DST), Government of India showed in a paper published along with Subhasish Chakrabarty, his student, that the geometry of space-time can cause neutrino oscillations through quantum effects even if neutrinos are massless. It was published in the journal ‘European Physical Journal C’.
Einstein’s theory of general relativity says
- that gravitation is the manifestation of space-time curvature.
According to the SNBNCBS team,
- 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.