Scientists discover Higgs boson-like 'God particle'
Scientists this evening confirmed they have discovered a particle fitting the description of the Higgs boson, the so-called 'God particle' seen as key to understanding how the universe is built.
The Royal Society's Science Media Centre wraps up developments:
Confirmation that the Higgs boson-like particle had been discovered in experiments carried out at the Large Hadron Collider came in a press release from CERN (which houses the LHC). Scientists also outlined the technical details in a seminar at the International Conference for High Energy Physics in Melbourne.
Watch the animation below to to see a portrayal of the concept of the Higgs field and its influence on elemental particles.
Professor Peter Higgs of the University of Edinburgh has welcomed results from CERN today that give the strongest evidence yet of the existence of the Higgs boson, a theoretical physical particle that was first postulated by Prof Higgs in the 1960s:
"Scientists at CERN are to be congratulated on today's results, which are a great achievement for the Large Hadron Collider and other experiments leading up to this," he comments.
"I am astounded at the amazing speed with which these results have emerged. They are a testament to the expertise of the researchers and the elaborate technologies in place.
"I never expected this to happen in my lifetime and shall be asking my family to put some champagne in the fridge."
Ranks with Rutherford's discovery of the atomic nucleus
Professor Richard Easther, Head of Department, Department of Physics, University of Auckland comments:
"The news from CERN marks a huge step forward for particle physics. We are definitely seeing a new class of particle for the first time in 30 years, and this new particle looks like the long-sought Higgs boson. If this identification holds up we will understood why subatomic particles have mass, a breakthrough that would rank with Rurherford's discovery of the atomic nucleus.
"The LHC was built by a global collaboration, including New Zealand scientists. University of Auckland physicist Dr David Krofcheck is a member of the CMS collaboration at CERN, one of the two big detectors that contributed to today's announcement."
On the verge of understanding one of the biggest mysteries of the Universe
Professor Mark Kruse (a New Zealander), Associate Professor of Physics at Duke University, comments:
"I have just finished watching the releases by the CMS and ATLAS experiments at the ICHEP meeting in Melbourne (where about 500 physicists are watching). Pretty electrifying atmosphere here.
Both experiments report an observation (at about the 5-sigma level) of a Higgs-like Boson. My comment(s) are as follows:
"It is now clear that something new has been seen at the LHC that will open up a whole new era of exploration, making this a very exciting time in particle physics. It remains to be seen if what has been discovered is indeed the Higgs Boson of the Standard Model(SM) of particle physics. But either way, we are on the verge of understanding one of the biggest mysteries of the Universe, that of how the masses of fundamental particles are generated. It will take more time to determine if this is the SM Higgs boson, or one of perhaps many different types of Higgs bosons in a more exotic theory, or, something else entirely.
"Once resolved, we will be one step further in our quest for an understanding of what happened in the first trillionth of a second of the Universe that made it what it is today. However, I will note that the discovery of the Higgs boson, if indeed we have found it, is by no means the end of the story, in fact
in some sense it is only the beginning."
Most important and profound discovery in particle physics in almost 30 years
Professor Anthony Thomas is Director of the Adelaide Node of the ARC Centre of Excellence in Particle Physics at the Terascale. He is based at the University of Adelaide's School of Chemistry and Physics. He comments:
"Today's announcement that the Higgs boson has been discovered at CERN represents the most important and profound discovery in particle physics in almost 30 years. The Higgs represents the key missing piece of the jig-saw puzzle that is the famous Standard Model of nuclear and particle physics. It has been anticipated for more than four decades and were it not there theorists all over the world would have been back to their drawing boards in desperation. Now that it has been found, there is not only a palpable sense of relief but a great deal of excitement as we begin to pore over the details of the various experimental results to see what hints they may have for completely new physics which goes beyond the Standard Model."
A cornerstone of Einstein's dream
Dr Csaba Balazs is Director of the Monash Node of the Centre for Particle Physics at the Terascale, Monash University, Melbourne comments:
"The existence of the Higgs boson is a cornerstone of Einstein's dream. In 1955 Albert Einstein died without fulfilling his lifelong dream: the unification of all physical laws in a single equation. Since then thousands of physicists have pursued the quest for unification. Various theories have been worked out that might realise the dream, however we do not know which one, if any, is correct.
In 1983 a glimpse of hope for unification emerged in the form of the discovery of two particles called the W and Z bosons. The existence of these particles proved that the unification of two out of four fundamental forces is possible. However, the unification was not complete without the existence of a hypothetical third particle: the Higgs boson. So the existence of the Higgs particle became one of the cornerstones of unification.
In 1991 the construction of the Superconducting Super Collider started. This machine was going to be powerful enough to find the Higgs boson. Unfortunately, in 1993 the project was cancelled by the US Congress, and Einstein's dream once again was fading away. Today, after 50 years of its theoretical introduction, we have learned that the Higgs boson probably exists! This is a tremendous step ahead in our fundamental understanding of unification and in realizing Einstein's dream."
Could hardly be a more exciting time
Associate Professor Kevin Varvell is Director of the Sydney Node of the ARC Centre of Excellence for Particle Physics at the Terascale. He is based in the School of Physics at the University of Sydney comments:
"This could hardly be a more exciting time for our field of research. The Higgs boson has been searched for using progressively larger and more sophisticated accelerators and detectors for 30 or 40 years now. Whilst it is too early to say yet whether the new particle which has been seen is the Higgs predicted by our Standard Model of Particle Physics, or something even more interesting, it is fair to say that we have taken a very big step forward today. Now the hard work begins to flesh out what this new thing really is."
Without the Higgs there would be no stars and ultimately no life
Prof Themis Bowcock, Head of Particle Physics at the University of Liverpool, comments:
"This is cast-iron proof that a new particle has been discovered. It looks like the Higgs.
"For physicists the dice are definitely now loaded in favour of a discovery. Based on the CERN results alone there appears to be less than one chance in a million that this is fake, which is roughly the same probability as flipping a coin heads-up 21 times in a row. Very few physicists would privately argue that this is not a Higgs particle.
"Half a century after it was first proposed, and after a monumental effort by generations of physicists around the world, the discovery of the Higgs represents a major breakthrough in our fundamental understanding of nature. For physicists, this is the equivalent of Columbus discovering America.
"Each of the two experiments (ATLAS and CMS) searching for the Higgs have presented data which, independently, surpass the 'gold-standard' for discovery which they themselves have set. Although the ATLAS and CMS teams are keen to point out the preliminary nature of this data, newly released data from the Tevatron at Fermilab in the US seem to support the Higgs hypothesis.
"Our perception of the Higgs is that it is like no other fundamental object in nature. Our modern understanding of physics - known as the Standard Model - relies on the existence of the Higgs boson, which interacts with other particles making some very heavy whilst leaving others light. This shapes the Universe we know today.
"For the last 40 years it has allowed us to understand phenomena such as light, the way the sun burns, and how atoms and nuclei are held together. Without the Higgs there would be no stars and ultimately no life.
"Physicists have laboured for decades to reach this goal but a huge task still awaits them. Mapping out the properties of this new particle is the next step, it opens a new era in Particle Physics and will take years more painstaking work. But the stakes could not be higher. The Higgs offers humanity, for the first time, a unique glimpse into why nature is the way it is."
Q&A with scientists
SS = Stefan Söldner-Rembold at the University of Manchester
JG = Prof Jerome Gauntlett, Head of Theoretical Physics at the Blackett Laboratory, Imperial College London
Q. I understand that it is the Higgs field that confers mass but what is the relationship of the Higgs boson to the field? And if it is the field that confers mass, what does the Higgs boson do?
SS: "In quantum theory all fields have "quanta" associated with them. As an example, the photon is the quantum of the electromagnetic field. In analogy, the Higgs boson is the particle related to the Higgs field."
JG: "The Higgs field permeates throughout the whole universe. A Higgs boson can be thought of as a little ripple of the Higgs field. It is the smallest ripple allowed by quantum mechanics."
Q. I understand that the field is around us all the time. Are Higgs bosons there too? I.e. are they being made in nature all the time or were they only made in the fraction of the second after the Big Bang, hence the need to recreate these conditions?
SS: "Higgs particles are very heavy and it therefore requires a lot of energy to produce them. This is the reason we need high-energy accelerators like the LHC."
JG: "It takes a lot of energy to create real Higgs bosons. Also they are very short lived and decay rapidly into other particles. It is this process that is being observed at LHC."
Q. if the field is there all the time, why not just look for it? Or is it even harder to detect?
SS: "The Higgs field interacts with the fundamental particles that make up the world around us and it gives them their mass. When measuring particle masses we see the Higgs field at work. However, to get a positive proof that this theory is really correct we need to find the Higgs particle which comes with the field. Peter Higgs actually postulated the existence of the Higgs particle as an afterthought to his original paper as a possible experimental signature of his theory."
JG: "The Higgs field provides a mechanism to generate mass in various elementary particles. In particular, the fact that the W-bosons and the Z-bosons have mass is good indirect evidence for the Higgs field. Detecting the Higgs boson will provide a direct test for the existence of the Higgs field itself."