lundi 4 juillet 2016

Neutrino physics cold[ol] case{s}

The 20th century (story of the) neutrino
In the recent past, two Nobel Prizes were given to Neutrino Physics. In 2002 Ray Davis of USA and Matoshi Koshiba of Japan got the Nobel Prize for Physics while last year (2015) Arthur McDonald of Canada and Takaaki Kajita of Japan got the Nobel Prize. To understand the importance of neutrino research it is necessary to go through the story of the neutrino in some detail. 
Starting with Pauli and Fermi, the early history of the neutrino is described culminating in its experimental detection by Cowan and Reines. Because of its historical importance the genesis of the solar neutrino problem and its solution in terms of neutrino oscillation are described in greater detail. In particular, we trace the story of the 90-year-old thermonuclear hypothesis which states that the Sun and the stars are powered by thermonuclear fusion reactions and the attempts to prove this hypothesis experimentally. We go through Davis’s pioneering experiments to detect the neutrinos emitted from these reactions in the Sun and describe how the Sudbury Neutrino Observatory in Canada was finally able to give a direct experimental proof of this hypothesis in 2002 and how, in the process, a fundamental discovery i.e. the discovery of neutrino oscillation and neutrino mass was made. 
We next describe the parallel story of cosmic-ray-produced neutrinos and how their study by SuperKamioka experiment in Japan won the race by discovering neutrino oscillations in 1998. 
Many other important issues are briefly discussed at the end...
Milestones in the neutrino story

  • 1930 Birth of Neutrino: Pauli 
  • 1932 Theory of beta decay, ”Neutrino” named: Fermi
  • 1954 First detection of neutrino: Cowan and Reines 
  • 1964 Discovery of muneutrino: Lederman, Schwartz and Steinberger 
  • 1965 Detection of atmospheric neutrino: KGF 1970 Start of the solar neutrino experiment: Davis 
  • 1987 Detection of neutrinos from supernova: SuperKamioka 
  • 1998 Discovery of neutrino oscillation and mass: SuperKamioka
  • 2001 Discovery of tauneutrino: DONUT 
  • 2002 Solution of the solar neutrino puzzle: SNO 
  • 2005 Detection of geoneutrinos: KamLAND 
  • 2013 Detection of ultra high energy neutrinos from space: Ice Cube 

G Rajasekaran (Institute of Mathematical Sciences, Chennai & Chennai Mathematical Institute) (Submitted on 22 Jun 2016)

A potential 21st century counterpart...
What exactly is Dark Matter? New theories for what really constitutes Dark Matter appear to make the news headlines every week. At a slower pace, these theories are slowly being eliminated. We revisit this scientific thriller and make the case that condensed neutrino matter is a leading suspect. We provide a forensic discussion of some subtle evidence and show that independent experimental results due out in 2019 from the KATRIN experiment [1] will either be the definitive result or eliminate condensed neutrinos as a Dark Matter candidate... The ... experiment ... will have the sensitivity to determine the mass of the electron antineutrino down to 0.35 eV/c2 ... This mass range for the electron antineutrino is in direct contradiction to the upper bound claimed by the Planck satellite consortium. If KATRIN discovers a neutrino mass in this range, we contend that the cosmological blackbody radiation raw data analysis must be revisited and that it would be a major finding endorsing condensed neutrinos as the so-called Dark Matter, which everyone has been looking for.
(Submitted on 27 Jun 2016)
... and another speculative (rival?) one here



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