Jeff Forshaw, professor of particle physics at the University of Manchester, writes: There is utter joy in the world of particle physics – Cern’s announcement that a new particle has been discovered will have long-lasting consequences for our understanding of how the universe works and it paves the way for a swathe of exciting new results over the coming years.

All the evidence points to this new particle being the long-sought Higgs boson. Its discovery is testament not only to the brilliance of the experimental physicists and engineers from around the world who have built the Large Hadron Collider but also to the theoretical physicists who dreamed of its existence almost 50 years ago.

Fundamental science like this is thrilling, not least because of the way that years of hard work, experimentation and mathematical analysis have led us to a worldview of astonishing simplicity and beauty.

We have learned that the universe is made up of particles and that those particles dance around in a crazy quantum way. But the rules of the game are simple – they can be codified (almost) on the back of an envelope and they express the fact that, at its most elemental level, the universe is governed by symmetry. Symmetry and simplicity go hand in hand – half a snowflake is enough information to anticipate what the other half looks like – and so it is with those dancing particles. The discovery that nature is beautifully symmetric means we have very little choice in how the elementary particles do their dance – the rules simply “come for free”. Why the universe should be built in such an elegant fashion is not understood yet, but it leaves us with a sense of awe and wonder that we should be privileged to live in such a place. [Continue reading…]

Themis Bowcock writes: Early this morning, the physicists sat, with the media poised, waiting for two technical seminars from Cern to be delivered. There was only one question we all really wanted answered – would there be enough evidence to prove the Higgs particle had been discovered?

In London, John Womersley told us: “I can confirm that a particle has been discovered that is consistent with the Higgs boson theory.” In Cern, a spokesman said: “This is a preliminary result, but we think it’s very strong and very solid.” So there we have it. But what does the discovery of the Higgs actually mean to us? The answers lie in what the Higgs particle is and precisely what its role is in how the universe works.

About 50 years ago, physicists were faced with a conundrum in their theories of quantum mechanics, which describes nature at its most fundamental level. A successful theory called quantum electro-dynamics had been developed, which explained how particles of light and matter interacted. It was described as the “jewel of physics”, but while it correctly assumed that particles of light had no mass, it left a gap in our understanding of why otherwise similar particles were very heavy. For example we now know the particle of the force responsible for radioactivity is 100 times heavier than a hydrogen atom, but at the time we didn’t understand why. Two British scientists, Tom Kibble and Peter Higgs, decided to tackle this problem. They discovered that it is theoretically possible to make a particle without mass behave as if it did.

The Higgs theory suggested that nature, as it cooled after the big bang, froze into a unique configuration. The Higgs mechanism predicted that new particles came into existence as part of this freezing – “children” of the freeze. We now believe these Higgs particles are responsible for giving fundamental particles their mass and can leave them heavy or completely without mass; it’s as if the stickier a particle is to the Higgs, the heavier it is.

One of the great aims of modern physics has been to generate these Higgs particles. To create the right conditions for their study, huge accelerators such as the Tevatron in Illinois and the Large Hadron Collider in Geneva were built involving thousands of physicists and tens of thousands of engineers over decades, with funding from around the globe.

The Higgs particle is the first truly new particle that mankind has conceived – and now discovered – for millennia. Philosophers and scientists have reduced the world first to atoms, then fundamental particles, and then even the very quanta of the forces such as light.

The Higgs particle is not simply about the matter of which we are composed, nor about how it communicates (like light reaching our eyes from a distant galaxy), nor is it another layer of an infinite onion of smaller and smaller particles. It is the first part of the mechanism that tells us why the universe is the way it is today, why the stars burn the way they do and why light and matter are the way they are. Who among us can begin to imagine where this will lead in a century, let alone a millennium? [Continue reading…]

'The search is more advanced today than we imagined possible,' said ATLAS spokesperson Fabiola Gianotti. 'We observe in our data clear signs of a new particle, at the level of 5 sigma, in the mass region around 126 GeV. The outstanding performance of the LHC and ATLAS and the huge efforts of many people have brought us to this exciting stage. A little more time is needed to finalize these results, and more data and more study will be needed to determine the new particle’s properties.'

Wired Science reports: Prepare the fireworks: The discovery of the Higgs boson is finally here. Early in the morning on July 4, physicists with the Large Hadron Collider at CERN announced they have found a new particle that behaves similarly to what is expected from the Higgs.

“As a layman, I would now say, I think we have it,” said CERN director-general Rolf-Dieter Heuer. “It’s a historic milestone today. I think we can all be proud, all be happy.” Both CMS and ATLAS, the two main LHC Higgs-hunting experiments, are reporting a boson that has Higgs-like properties at a mass of 125 gigaelectronvolts (GeV) with a 5-sigma significance, meaning they are 99.999 percent confident of its existence.

At the first mention of 5-sigma by physicist Joe Incandela, who presented results from one of the main Higgs-searching efforts at the LHC, the audience burst into applause. “It was really a magnificent moment to see the reaction from the community,” he said later in a question and answer session. “Emotionally it didn’t really hit me until today because we have had to be so focused, and so much work to do.”

Though CERN scientists are making sure to be cautious about over-interpreting their data, the results are impressive and historic, and today will likely go down as the day the Higgs discovery was announced.

“This boson is a very profound thing that we have found. This is not like other ordinary particles,” Incandela said. “We are reaching into the fabric of the universe like we’ve never done before. It’s a key to the structure of the universe.”

First hypothesized in the 1960s, the Higgs boson is the final piece of the Standard Model, the physics framework explaining the interactions of all known subatomic particles and forces. The Higgs has been the subject of an extensive two-decade search, first at the European Large Electron-Positron Collider, then the Tevatron at Fermilab in Illinois, and finally at the LHC. Finding the Higgs within the predicted energy range is a major vindication for the Standard Model.

Peter Higgs

“I never expected this to happen in my lifetime and shall be asking my family to put some champagne in the fridge,” physicist Peter Higgs, the particle’s namesake who first theorized the existence of the particle, said in a statement.

The Higgs is certainly the most important discovery in the field for a generation. The last of the Standard Model’s 16 particles to be found was the top quark, discovered at Fermilab’s Tevatron in 1995, while many physicists would point to the detection of the W and Z boson in 1983 as the field’s most recent monumental finding. And considering that it is gives rise to the mass of all other particles, the Higgs may well be the most important new particle found for years to come.

Discovering the Higgs boson is not likely to radically change life for most people — it will not lead to better communications devices or fancy new electronics. But knowing its characteristics will bring physicists a better understanding of nature. The Higgs is important because it is the manifestation of the Higgs field, which is thought to permeate all of space and interact with all other subatomic particles. This interaction leads to the different mass for each elementary particle. Some particles, like protons, are slowed by this field, like a tennis ball going through molasses, and are relatively heavy while others, like electrons, shoot rapidly through like BB gun pellets, making them light.

Phys.org explains: A Higgs boson is an excitation – a fleeting, grainy representation – of the Higgs field, which extends throughout space and gives all other particles their mass.

At the instant of the big bang, everything was the same as everything else, a state of symmetry that lasted no time and was immediately broken. Particles of matter called fermions emerged from the sea of energy (mass and energy being interchangeable), including quarks and electrons that would much later form atoms. Along with them came force-carrying particles called bosons to rule how they all were related. All had different masses – sometimes wildly different masses.

Using the concepts of a Higgs field and Higgs boson, the Standard Model explains why quarks, protons, electrons, photons, and a wide-ranging zoo of other particles have the specific masses they do. Oddly, however, the Standard Model can’t predict the mass of the Higgs itself. That will only be learned from experiment.

The following animation explains the Higgs boson. (The very noisy intro in the CERN cafeteria only lasts about 40 seconds.)

More on the Large Hadron Collider, particle physics and the evolution of the universe from English particle physicist, Brian Cox.