Scientists this evening confirmed they have discovered a particle fitting the description of the Higgs Boson, the so-called ‘god particle’ that is seen as key to expanding our knowledge of particle physics and the make-up of the universe.
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.
Commenting on the findings, CERN Director General Rolf Heuer said:
“We have reached a milestone in our understanding of nature. The discovery of a particle consistent with the Higgs boson opens the way to more detailed studies, requiring larger statistics, which will pin down the new particle’s properties, and is likely to shed light on other mysteries of our universe.”
The technical presentations in Melbourne were mindblowingly complicated – but over at the Science Media Centre we gathered some commentary from scientists all over the world – here’s some of the reaction.
Professor Matt Visser, Professor of Mathematics at Victoria University of Wellington comments:
“Certainly enough [here] to claim discovery. Compatible with the standard model of particle physics; some rather vague but inconclusive hints of ‘beyond standard model’ physics.
“No sign of supersymmetry, no sign of large extra dimensions, no sign of technicolor, no sign of “strong gravity”, or any of the more “exotic” proposals theorists have come up with since the standard model was formulated.
“Not enough yet to completely rule out “exotic” physics; I soon expect to see a flurry (avalanche?) of theory and phenomenology papers picking at the details. More importantly, there is still a lot of work for the experimentalists in fully exploring the present data, and collecting more data, to extract as much information as possible. This is just the beginning…”
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.”
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 understand 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.
“The University of Auckland is hosting an international workshop next week (July 13-15) which will discuss the implications of the discoveries at the LHC for astrophysics and cosmology. The meeting will bring together New Zealand’s fundamental physics community and a number of the world’s leading experts in particle physics. Today’s announcements from Geneva are bound to be the biggest topic of conversation at our workshop, and at many conferences to come.”
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.
“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.”
Professor Sir Timothy O’Shea, Principal of the University of Edinburgh, comments:
“We are delighted at this significant development in the search for the Higgs boson, and congratulate Professor Peter Higgs on this.
“This particle is integral to our understanding of the physical world and evidence of its existence is a testament to Professor Higgs and to all the scientists who are working to uncover it.
“Professor Higgs has inspired many colleagues and students over the years, some of whom have also gone on to become involved in the Large Hadron Collider experiments. His legacy will continue to inspire future generation of physicists, at Edinburgh and beyond.”
Prof Stefan Söldner-Rembold, Professor of Particle Physics at the University of Manchester, comments:
“Today we have witnessed a discovery which gives unique insight into our understanding of the universe and the origin of the masses of fundamental particles. There is no doubt that the Higgs particle exists and we now have to understand its properties and whether it behaves exactly as predicted by theory.
“This discovery is the first milestone of the LHC physics programme and opens the door to many more exciting discoveries by the LHC experiments in the next decade.
“Particle physicists at the University of Manchester’s play a leading role on the ATLAS experiment and have built part of the ATLAS detector. ”
Professor Tejinder Virdee FRS, Imperial College London, comments:
“Today is a historic day. A new heavy particle, the first of its kind, has been observed in CMS. It took 20 years to build the CMS detector, arguably the most complex scientific instrument ever built. This result is a tribute to the talent and dedication of thousands of scientists and engineers from about 40 countries that built and now operate CMS. Within the experimental precision achieved so far the results appear consistent with expectations for a standard model Higgs boson.
“The Higgs boson is the last and key missing element of the highly successful standard model, one of the great achievements of 20th century science. More data are required to reveal whether it has all the properties of the standard model Higgs boson or whether some do not match, implying new physics beyond the standard model. I believe this observation opens the door to a new vista of physics that will take many more years to explore.”
Professor Dave Charlton, Deputy Spokesperson for the ATLAS project from the University of Birmingham’s School of Physics and Astronomy, comments:
“Many people have been working night and day to analyse the fresh data from the LHC which has been pouring in this year, which has allowed us to reveal these exciting preliminary results today. The tantalising hints we saw in December are repeated and strengthened in the new ATLAS data, so we’re now quite confident that we’re seeing a new particle. Finding out if it’s got all the properties of the Standard Model’s Higgs boson will need a lot more data and painstaking work. We’re now opening a new chapter of fundamental physics, as the LHC was designed to do.”
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.”
Professor Bowcock is one of a team of scientists at the University of Liverpool working at the Large Hadron Collider
Q&A with scientists:
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.”
SS = Stefan Söldner-Rembold at the University of Manchester
JG = Prof Jerome Gauntlett, Head of Theoretical Physics at the Blackett Laboratory, Imperial College London