Glimpsing Higgs Boson: tracing subatomic particle amid the debris

The shimmering trails of shattered particles reveals evidence of a massive particle that matches the predicted profile of Higgs Boson. Scientists are already eagerly looking for ways that it may diverge from expectations and therefore help unravel elements of their previous theories. This is how knowledge and theory develop. Theoretical proposals, testing in practice, confirmation and new problems, new theoretical reaching and controversies, new practice.

“I would be delighted if this new state is a Higgs boson, but perhaps not the Standard Model Higgs boson,” physicist Fabiola Gianotti of the LHC’s ATLAS experiment said after the announcement, with an apology aside to Peter Higgs. “Because this will open the road to something else.”

This first appeared in Wired Science.

Newly Discovered Particle Appears to Be Long-Awaited Higgs Boson

by Adam Mann

 

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.

“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.

To search for the Higgs, the LHC has been smashing together protons at incredibly high speeds, counting out the many elementary particles created from these energetic slams. Heavy particles, like the Higgs boson, almost immediately decay into simpler fragments.

What physicists have been searching for are characteristic decays that indicate the existence of the Higgs. Since the process is somewhat chaotic, it takes a long time to sift through the results and determine which decays are indicating which particles.

That’s why particle physicists use statistics to interpret their results, proving that a small excess of certain decays is not just a coincidence. In December, the LHC had collected enough data to ascertain that some events were pointing to the creation of Higgs particles at 125 (GeV) with a 3-sigma significance, meaning they had a 0.13 percent chance of happening by chance. What they have been waiting for is the stringently high bar of a 5-sigma result, which has only a one in 3 million chance of happening randomly.

During their talk, the LHC spokespeople stressed that their results are preliminary and will require further analysis to ensure the new particle is the Higgs boson. Yet plenty of other physicists are willing to call the Higgs a Higgs. “Many commenters out there are right in pointing out that no matter what CERN says, the world today will know that the Higgs boson has been discovered,” wrote particle physicist Tommaso Dorgio on his blog.

With the Higgs basically announced, scientists now move into unknown territory. Many physicists are hopeful that some properties of the boson will turn out different than predicted under the Standard Model. If this is the case, it could indicate the presence of new physics such as supersymmetry that would build on the Standard Model and fix certain problems with it.

“I would be delighted if this new state is a Higgs boson, but perhaps not the Standard Model Higgs boson,” physicist Fabiola Gianotti of the LHC’s ATLAS experiment said after the announcement, with an apology aside to Peter Higgs. “Because this will open the road to something else.”

Scientists have been waiting a long time for this moment, said theoretical physicist Mark Wise from Caltech. Whereas before all they could do is build models that seemed correct based on inference, there may soon be real data to confirm or deny their theories.

“The rubber has hit the road,” he said. “Which is important because physics isn’t about theoretical speculation, it’s about how nature behaves.”

As yet, there have been no indications for physics beyond the Standard Model and the latest Higgs results are very consistent with the theory. This is problematic since some physicists had expected to see some interesting or new particles by now yet nothing has yet appeared. Some researchers are hoping details of the Higgs properties will point to the place they should look.

“What would be the worst scenario, is if the Higgs boson turns out to be exactly what’s in the present theory, and there’s no hint of anything else,” said Wise.

But there is still hope. After this year, the LHC will go into two years of shutdown to do repairs. When it comes back online, it will be at much higher energy, able to probe far more interesting places.

In particular, many scientists are looking out for any particles that could correspond to the dark matter seen in galaxies throughout the universe. The ordinary protons and electrons that make up most things on Earth are outnumbered five to one by this dark matter. Perhaps the LHC can uncover exactly what this matter is in 2015 and 2016, when it runs at full capacity.

“If I had to place a bet, it’s during those times we might make another big discovery, that might be as big or even bigger than the Higgs,” said physicist Beate Heinemann of the University of California, Berkeley, who works on one of the LHC’s Higgs-searching experiments, ATLAS.

Image: Scientists assemble the endcap for the ATLAS experiment, one of the LHC’s two main experiments. Peter Ginter/CERN

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  • Guest (Carl Davidson)

    Found this on DailyKOS this AM, a simplified metaphor, but good:

    "The Higgs field is like rain, and there is no place you can go to keep dry. Just like there’s no way to shield yourself from gravitation, there’s no way to hide from the rain that is the Higgs field. If there were no Higgs field, all the fundamental particles would be like dried-out sponges. Massless, dried-out sponges."

    Also, Scientific American's 'Instant Egghead' feature offers a two-minute video that isn't bad, either. Access it through the OUL, at the bottom of this page: http://ouleft.sp-mesolite.tilted.net/?page_id=405

  • Guest (Contrarian)

    A Higgs boson walks into a church, according to one joke which did the rounds.

    "We don't allow Higgs bosons in here!" shouts the priest.

    "But without me, how can you have mass?" asks the particle.

  • Guest (Miles Ahead)

    And, also, what I found interesting was the way many in the U.S. news media treated this development and discovery politically. The question asked over and over to some expert guest--"Since the Higgs Boson was discovered in Switzerland," (at CERN which happens to be an internationally participatory center), "do you think the U.S. is falling behind in its scientific research?" OMg-particle.

  • Miles:

    I agree. It is important to note (and counteract) the way that "making America competitive" and "keeping America #1" has become a theme that soaks almost <em>everything</em> discussed in national official politics. Education of young? It is about economic competitivensess (are "we" as good as chinese high schoolers?). Provide healthcare to poor people? The question is can "America be competitive" if it adopts such new "entitlements." Every idea, change or problem is portrayed in the context of competition with China and other economic "rivals."

    Such political frameworks are totally toxic.... and totally capitalist (in their basis and implications).

  • Guest (Miles Ahead)

    And certainly I agree with you Mike, as to the examples you laid out. But will add to the potpourri and underlying (but probably obvious to many, certainly to you) point that "keeping America Número Uno" is a necessity for the U.S. imperialists in beefing up its chauvinism, jingoism, patriotism--and all those disgusting "isms" for world domination, even in the realm of scientific discovery.

    Lest we not forget the (phony-ass) "Sputnik crisis" as example, and the freneticism and consternation the Soviets' launch caused the U.S. rulers...which in turn gave fodder (and justifications) to the already existing "Cold War."

  • Guest (Gary)

    I was a little concerned that reports of the discovery of the "God particle" might somehow be used towards religious ends, as other scientific breakthroughs have been used in the past. (The Big Bang theory was propounded by the Belgian priest and astronomer Georges Lefebre from 1927; he thought it confirmed Christianity...) I imagine some folks will find ways to say this "poof of the God particle" is "proof of the existence of God" (because who else could have come up with something so amazing?)

    Anyway it was good to see press reports that Peter Higgs himself, born in northern England and long a professor at University of Edinburgh, is a staunch atheist who's always opposed the term.

  • I have noticed that a lot of reporting now has dropped the "god particle found" theme... and i assume it is for that reason.

    There has been value in scientists learning to popularize their work and discoveries (starting with naming particles "quark", and calling properties "spin," and naming something "nuclear winter" etc. etc. -- so that the controversies can more easily go viral).

    but the "god particle" was (from the beginning) a bad choice, laden with ways it obstructed the conveying of the discovery, and obscuring it all beneath a misunderstanding that scientists were finding proof of god.

    When picking this post, we (obviously) consciously picked an article that didn't use the "god particle" label.

  • Guest (P.Ranch)

    Gary, I think you are mistaking Georges Lefebre for Georges Lemaitre. Either way, Lemaitre wasn't simply philosophizing about the nature of the Universe. He was a mathematician and physicist, and was one of the first to apply the equations of General Relativity and consider the implications of the expanding Universe, which the theory seemed to describe. As for utilizing it to justify Christianity, at least the article below claims that he opposed attempts to use the Big Bang theory to validate the Genesis creation story, the way groups like Answers in Genesis have more recently:

    http://www.amnh.org/education/resources/rfl/web/essaybooks/cosmic/p_lemaitre.html

    I have no problem with people coming from religious backgrounds contributing to science. The Big Bang theory is one of the most important scientific breakthroughs of the 20th century, why should it matter if it was derived and described by a Belgian priest?

    I think the real problem is when scientific breakthroughs are taken apart and used piecemeal to support religious ideas like Intelligent Design and Creationism, which are wholly unscientific and undermine science. But it is a GOOD thing when religious people accept science, engage in science, and learn how to think scientifically. Religion isn't going away anytime soon, and will certainly exist in a socialist society. If religious people draw justification for their beliefs from science, that's fine if they actually understand the issue scientifically. As long as they aren't actively trying to "reverse the stifling materialist world view and replace it with a science consonant with Christian and theistic convictions" (Wedge Strategy), then I think that opens up the possibility of discussing philosophy, morality, and the implications of certain world views amongst friends and allies. Consider the example of the Clergy Letter Project and Evolution Sunday.

  • Guest (bezdomni)

    “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 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.

    http://press.web.cern.ch/press/PressReleases/Releases2012/PR17.12E.html

    ------------------------------

    The facts are:

    * This particle is the heaviest boson that has been discovered.
    * There is very little uncertainty (smaller margin than 1/1,000,000) that the model for this particle is consistent with the experimental results.
    * The particle seems to have all the properties of the Higgs Boson from the Standard Model, but further investigation may reveal additional properties that go beyond the standard model.

  • Guest (bezdomni)

    "I was a little concerned that reports of the discovery of the “God particle” might somehow be used towards religious ends, as other scientific breakthroughs have been used in the past."

    Crackpots gonna crackpot. Refute them when doing so will set a good example for scientific inquiry and ignore them when it isn't worth the time.

    There are few people who would take such claims seriously. Those who would have much deeper issues with basic scientific education and wouldn't know or care very much what a Higgs Boson is anyway.

    Even most religious people understand that particle physics cannot prove the existence of God.

    "Anyway it was good to see press reports that Peter Higgs himself, born in northern England and long a professor at University of Edinburgh, is a staunch atheist who’s always opposed the term."

    Why? Would his contributions to science be any less valuable if he was a Christian? Or if he didn't mind the term?

    I don't see how this matters at all, except perhaps to people who are interested in biographical details about Peter Higgs.

    If people stop believing in God because they think being an atheist means they're smarter than non-atheists or because certain people they admire are atheists, then they have stopped believing in God for the wrong reason. A lot of the efforts to popularize atheism get it all wrong, it makes rejection of religion come off as childish and smug.

    I honestly don't care if he was an atheist or not. It makes no difference to me if he believed in God or not.