As news of the discovery of the Higgs Boson set off Higgsteria, leading Australian theoretical physicist Professor Bruce McKellar explained what it means for physics, Australia and the future.
Speaking between sessions of the 34th International Conference on High Energy Physics in Melbourne, Professor McKellar said that the most exciting part of the Higgs announcement was that it was “a discovery”.
“It has changed how particle physicists will work. Now, they will impose on themselves a rule that says that a new particle should appear at a level which they call ‘five standard deviations’. This means that there is less than one chance in a million that a random fluctuation could have produced the result. The experimentalists now believe that they have a new particle. It looks like the expected Higgs, but its properties have not yet been established well enough to be sure,” said Professor McKellar.
Professor McKellar has been directly involved with CERN, from the early days of developing the Large Hadron Collider (LHC), to now having some of his students work in the experimental teams at the LHC.
For many, last week’s announcement came surprisingly fast, given the (LHC) has not been operating for many years. Professor McKellar the progress and process of the last few years leading to the discovery, “The rate at which events have been created was increased when the intensity of the beam in the Large Hadron Collider was increased to the design level and beyond. This happened more quickly than anticipated. There were “hints” disclosed at a symposium at CERN late last year. Those hints inspired a strong effort by the accelerator teams to produce an increased intensity, this then led to a non-stop effort to speed up the analysis. The speed was a result of very intense work, so knowing the level of work going on, the speed of the discovery was not too surprising.
Given that the Higgs discovery is a physics game-changer, Professor McKellar sees that there are now a range of new challenges and questions for science to address.
“We need to be working hard to explain the properties of the matter of which we are made. But that is only five per cent of the total mass of the Universe. There is 25 per cent that is “dark matter”, stuff that provides the gravitational attraction necessary to form galaxies and galactic clusters, and then there is 75 per cent which is “dark energy” something with a negative pressure, which accelerating the expansion of the Universe. Understanding dark matter and dark energy are major goals.
“The other two problems I would like to see solved are: “Now we probably have the Higgs, which gives protons, electrons and most of the elementary particles their masses. What is it that gives the neutrinos their masses?” and then, “We still have not found a strong enough manifestation of the asymmetry between matter and anti-matter to explain why there is not anti-matter in the Universe, but enough matter to create galaxies, planets, and us.”
Professor McKellar believes strongly that these questions, along with the Higgs discovery, Brian Schmidt’s Nobel Prize last year and Australia’s participation in the Square Kilometre Array will inspire the next generation of physicists.
“All of those things are vital in inspiring young people into physics and science, but I don't think that they have to be Australian. My generation was inspired by Sputnik. Australian physics is generally well regarded internationally, and Australian physicists a well linked to their overseas colleagues.”
For Professor McKellar, there are many more challenges still.
“I am interested to see physicists delve further into high temperature superconductivity, quantum information and quantum computing, seeing and understanding the structure of matter at the atomic level to create new materials, understanding complex systems and applying that to understand biological systems, playing a role in the important drive to a create a sustainable world in terms of energy, food, water and other resources. And they are just a few.
Professor Bruce McKellar is a long-time APESMA subscriber and theoretical physicist who has advised scientists working on the Large Hadron Collider particle accelerator on the Swiss-German border. In 2014, he will become the first Australian to hold the office of President of the International Union of Pure and Applied Physics (IUPAP) General Assembly in London.