Takaaki Kajita and Arthur McDonald Awarded Nobel Prize in Physics

Arthur B. McDonald, professor emeritus at Queen’s University in Canada, poses shortly after learning that he was a co-winner of the Nobel Prize for Physics at his home in Kingston, Ontario October 6, 2015.

Around the turn of the millennium, Kajita, working at the Super-Kamiokande detector in Japan, discovered that neutrinos from the atmosphere switch between two identities as they make their way to Earth.

McDonald told a news conference in Stockholm by telephone that the eureka moment was when it became clear that his experiment had proven with great accuracy that neutrinos changed from one type to another in traveling from the sun to Earth.

Up to two-thirds of the calculated tally of neutrinos coming from the Sun was missing, and no one knew where they were going.

The experiments conducted by Takaaki Kajita and Arthur B. McDonald revealed that the neutrinos had not been detectable as they had changed identities. This is a discovery which prove that even these exotic, infinitesimally small particles still have a measureable amount of mass to them.

The 8 million krona ($970,291) prize will be split evenly between Kajita and McDonald.

Due to the success of McDonald’s original SNO experiment, several universities and other research partners formed the underground SNOLAB laboratory, to further study neutrinos and their behaviour.

This “metamorphosis” requires that neutrinos have mass. “This year’s Nobel Prize in physics honors a fundamental step towards unveiling the nature of the neutrino”.

“Fortunately, I have many colleagues as well who share this prize with me”.

It was at Super Kamiokande, a neutrino detector built in an abandoned zinc mine in Japan, filled with 50 kilotons of purified water and lined with 13,000 photomultiplier tubes to detect the streaks of light, that Kajita collected evidence that the particles can oscillate between types.

Takaaki Kajita wins half of the 2015 Nobel Prize in Physics for proving that neutrinos have mass.

For decades the neutrino remained a hypothetical particle until American researchers proved that it was real in 1956.

“The universe has so many neutrinos that they contribute as much to the mass budget of the universe as do the stars we see in the sky”, Turner said.

These two discoveries have provided humankind with powerful new means to combat these debilitating diseases that affect hundreds of millions of people annually.

Many neutrinos are created in reactions between cosmic radiation and the Earth’s atmosphere. “Frederick Reines, 1995 Nobel Prize for his co-detection of the neutrino, described them as “… the tiniest quantity of reality ever imagined by a human being”.

MacDonald said scientists would still like to find the actual weight of neutrinos. Understanding their nature is key to understanding why the universe turned out the way it is.

A number of Polish scientists have assisted in the research which led to the Nobel prize in Physics.