Notice: Important information about COVID-19 here.

Beam me up - Big Bang theory further explained

By Costa Maragos Posted: September 15, 2016 6:00 a.m.

U of R members of the T2K team (l-r) Juan Pablo Velasquez, Dr. Roman Tacik and Dr. Mauricio Barbi. Missing is Paul Ostlund.
U of R members of the T2K team (l-r) Juan Pablo Velasquez, Dr. Roman Tacik and Dr. Mauricio Barbi. Missing is Paul Ostlund. Photo by Trevor Hopkin - U of R Photography.

A research team from the U of R has had a hand in the quest to solving one of life’s biggest mysteries - the evolution of the universe.

A University of Regina group of physicists is part of a global team of researchers that has broken new ground in the study of the elusive and mysterious neutrinos. These are extremely tiny subatomic particles considered the key to understanding the structure of our universe as we know it.

The U of R team is made up of:

  • Dr. Mauricio Barbi, professor of physics and team leader.
  • Dr. Roman Tacik, adjunct professor of physics and a research scientist for TRIUMF, Canada’s national laboratory for particle and nuclear physics and accelerator-based science.
  • Paul Ostlund, masters of science student.
  • Juan Pablo Velasquez, masters of science student.

The series of experiments is truly a global effort. The team here is taking part in the so-called T2K experiment involving more than 400 physicists from dozens of institutions in 11 countries. The Canadian T2K team consists of 40 scientists from eight institutions including the University of Regina.
 
The experiment is designed to investigate how neutrinos change, from one type (or flavour) to another, as they travel.  

How did this project get the name T2K? Well, it’s an abbreviation for two cities in Japan – Tokia and Kamioka.

An intense beam of neutrinos was generated in Tokai on the east coast of Japan and shot to the Super-Kamiokanda neutrino detector, 295 kilometres away in Kamioka. T2K stands for Tokai to Kamioka.

Neutrinos come in three types: electron neutrinos, tau neutrinos and muon neutrinos.

Juan Physics T2K Project
Juan Pablo Velasquez, masters of science student working on a Fine Grained Detector, one of the components used to measure neutrinos. (U of R Photography)

“A peculiar property of neutrinos is that one type can transform into another type while it travels,” says Barbi.

As Barbi explains, a muon neutrino can transform into an electron neutrino and so forth. This phenomenon is called neutrino oscillation.  

“An equivalent of this would be like driving to Calgary in a Honda and at some point your car transforms into a BMW.  The same happens with antineutrinos: a muon antineutrino can transform into an electron antineutrino,” says Barbi.
 
This revelation matters.

“One of the properties of the interaction between antiparticles and particles of the same species is that they completely annihilate each other when they meet, resulting in the production of pure energy,” says Barbi.  

“Now, if we assume that both matter and antimatter were generated at the same rate after the Big Bang, they would not exist for too long before an antiparticle would meet a particle, resulting in their annihilation. So, there wouldn’t be enough time for the formation of stars, galaxies, planets and ultimately, life, including us”.

However, we do exist, and that is a testament to the fact that the universe is not made of perfect symmetry.

As Barbi points out, there should be an asymmetry between the production of antimatter and matter so that, in the end, the universe was left with an excess of matter that so that all structures we know could be generated: from the tiny subatomic particles to stars and black holes.

“This asymmetry is known as Charge-Parity (CP) symmetry violation. The kind of mechanism that could produce such asymmetry at the intensity needed to explain the amount of existing matter is one of the most intriguing questions in all of science.”
 
The most recent results from the T2K experiment were presented at the 38th International Conference on High Energy Physics in Chicago.  

Says Tacik: “The results show the degree to which neutrinos change their type, and present strong evidence for an asymmetry between the oscillation processes involving neutrinos and antineutrinos. This asymmetry might be strong enough to explain why matter prevailed over antimatter after the Big Bang.”
 
“We are excited with the latest results and have been excited since the beginning of the experiment. These latest results now open the doors to possibly answering that extremely important question of why everything exists,” he adds.

Previous T2K results have already determined some of the neutrino oscillation properties to which the T2K collaboration was awarded with the 2016 Physics Breakthrough Prize.

The U of R team has played a leading role in the construction and operation of the Fine Grained Detector, which is one of the components used in Japan to measure the neutrinos. The team is also playing a key role in physics analysis and software development, and at the same time working with the rest of the Canadian team towards the upgrade of the existing T2K facilities to increase the experiment sensitivity to other neutrino properties and possible discoveries.

The experiment in Canada is supported thanks to funding from the Natural Sciences and Engineering Research Council of Canada, National Research Council of Canada, Canada Foundation for Innovation and TRIUMF, Canada’s national laboratory for particle and nuclear physics and accelerator-based science.