I figured with the big Higgs Boson news today, I would repost this fantastic video explaining what the Higgs Boson is and then round up some more resources for learning more about it and about what the discovery of a new particle today was and what it means.
Go to PhD Comics for individual images from the video.
For another introductory overview, Brian Greene (author of The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos is a dynamic and engaging lecturer who explained the Higgs Boson recently in anticipation of today’s news.
CERN’s press release on today’s observation of a new particle:
Geneva, 4 July 2012. At a seminar held at CERN1 today as a curtain raiser to the year’s major particle physics conference, ICHEP2012 in Melbourne, the ATLAS and CMS experiments presented their latest preliminary results in the search for the long sought Higgs particle. Both experiments observe a new particle in the mass region around 125-126 GeV.
“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,” said ATLAS experiment spokesperson Fabiola Gianotti, “but a little more time is needed to prepare these results for publication.”
“The results are preliminary but the 5 sigma signal at around 125 GeV we’re seeing is dramatic. This is indeed a new particle. We know it must be a boson and it’s the heaviest boson ever found,” said CMS experiment spokesperson Joe Incandela. “The implications are very significant and it is precisely for this reason that we must be extremely diligent in all of our studies and cross-checks.”
“It’s hard not to get excited by these results,” said CERN Research Director Sergio Bertolucci. “ We stated last year that in 2012 we would either find a new Higgs-like particle or exclude the existence of the Standard Model Higgs. With all the necessary caution, it looks to me that we are at a branching point: the observation of this new particle indicates the path for the future towards a more detailed understanding of what we’re seeing in the data.”
The results presented today are labelled preliminary. They are based on data collected in 2011 and 2012, with the 2012 data still under analysis. Publication of the analyses shown today is expected around the end of July. A more complete picture of today’s observations will emerge later this year after the LHC provides the experiments with more data.
The next step will be to determine the precise nature of the particle and its significance for our understanding of the universe. Are its properties as expected for the long-sought Higgs boson, the final missing ingredient in the Standard Model of particle physics? Or is it something more exotic? The Standard Model describes the fundamental particles from which we, and every visible thing in the universe, are made, and the forces acting between them. All the matter that we can see, however, appears to be no more than about 4% of the total. A more exotic version of the Higgs particle could be a bridge to understanding the 96% of the universe that remains obscure.
“We have reached a milestone in our understanding of nature,” said CERN Director General Rolf Heuer. “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.”
Positive identification of the new particle’s characteristics will take considerable time and data. But whatever form the Higgs particle takes, our knowledge of the fundamental structure of matter is about to take a major step forward.
Here was Brian Greene’s Facebook announcement earlier today:
Here’s the situation just announced at CERN:
Each of the experiments at the Large Hadron Collider has discovered a new particle with properties that are consistent with it being the long-sought Higgs particle. It will require more data and work to definitively establish that the particle is indeed the Higgs, but there’s now no doubt that a new particle has been found.
When this result was announced at CERN, the auditorium erupted into prolonged applause, fitting for this historic discovery. No doubt, physicists worldwide erupted into similar applause. Decades of work by thousands of scientists around the globe have resulted in this spectacular achievement.
And, finally, today Andy Parker, Professor of High Energy Particles at Cambridge University, answered questions about what the Higgs Boson is and what was newly discovered about it. His answer to the first, and most elementary, question:
1. What is the Higgs Boson?
Most people imagine particles of matter to be like little billiard balls, which are stuck together in some way to make the solid objects which we see around us. We naturally expect the billiard balls to have some substance in their own right, making them, and everything which they form, massive. However, in modern quantum theories, matter is nothing like this. All the particles would, if left to themselves, have no mass at all, and fly around at the speed of light. There would be no atoms or people to study them.
The Higgs field is the proposed answer to this mismatch between our equations and what we see. The Higgs field fills all of space, and as the particles try to move through it, their interactions with it cause them to appear to have mass. This slows them down and allows them to bind together into the familiar forms of matter which we observe. This is a completely different picture of nature than the one we instinctively imagine – instead of matter having its own intrinsic properties, and moving about in empty space, many of the properties of matter are actually only due to its interactions with an invisible, all-pervasive field. The properties of “empty” space are crucial to the physicist’s understanding of the world.
The Higgs boson itself is a vibration in the Higgs field, which can be created if enough energy is put into the field, like dropping a pebble into a pond. The LHC is the world’s highest energy particle collider, and the collisions it makes create enough disturbance in the Higgs field to observe the Higgs boson, if it exists.
He goes on to answer the questions: “Today CERN announced an update on the research, what did they find?”
“What more needs to happen for CERN scientists to confirm that the unexplained particle is indeed a Higgs Boson?”
“In the Standard Model (the simplest theory which describes the fundamental subatomic particles and the forces between them) it is hypothesized that there is only one Higgs Boson, but in the Supersymmetric Model (which, unlike the Standard Model, incorporates the physics of dark energy and the full theory of gravitation) there could be up to five Higgs Boson. If they are able to verify the signal is indeed a Higgs Boson, how will they know if it is one of many?”
“If the Higgs verifies the Standard model, does more than one Higgs undermine it in favour of Supersymmetry?”
“What role has Cambridge played in the research?”
“If the Higgs Boson particle(s) is confirmed, what are the next stages of research?”