Scientists have measured the mass of ghostly sub-atomic particles called neutrinos for the first time by using the observations of the Big Bang and the curvature of space-time.
Physical Review Letters
Cosmic Microwave Background:
Cosmic Microwave Background (CMB) can be referred to as the fading glow of the Big Bang, i.e. oldest light in the Universe.
Study of CMB helps scientists to study and measure accurately different cosmological parameters such as the age of the Universe and the amounts of matter in the Universe.
Neutrinos are any of three stable neutral elementary particles of the lepton family with a negligible rest mass and no charge. Neutrinos have a spin of 1/2.
They show very weak interaction with matter making it very difficult for scientists to study them. Previously, it was considered to be massless but now it has been considered that neutrinos have some mass and only this could help in solving the discrepancy between comparing the primary CMB and lensing measurements both from the CMB and galaxy lensing data using the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS).
Dr Adam Moss, from The University of Nottingham’s School of Physics and Astronomy said: “We observe fewer galaxy clusters than we would expect from the Planck results and there is a weaker signal from gravitational lensing of galaxies than the CMB would suggest.
“A possible way of resolving this discrepancy is for neutrinos to have mass. The effect of these massive neutrinos would be to suppress the growth of dense structures that lead to the formation of clusters of galaxies.”
In this discovery, scientists combined the results from the Planck spacecraft and measurements of gravitational lensing in which images of galaxies are warped by the curvature of space-time to check the mass of these ghostly particles. This study helped in solving the major problem in current standard model of cosmology.
According to estimations, the sum of masses of neutrinos is 0.320 +/- 0.081 eV (assuming active neutrinos with three flavours).
Professor Richard Battye from The University of Manchester said: “If this result is borne out by further analysis, it not only adds significantly to our understanding of the sub-atomic world studied by particle physicists, but it would also be an important extension to the standard model of cosmology which has been developed over the last decade.”
Massive neutrinos solve a cosmological conundrum – The University of Nottingham (http://goo.gl/yDph2Y)
Richard A. Battye et al. (2014). Evidence for Massive Neutrinos from Cosmic Microwave Background and Lensing Observations Physical Review Letters DOI: 10.1103/PhysRevLett.112.051303