Higgs boson-like particle discovery claimed at LHC

 

The moment when Cern director Rolf Heuer confirmed the Higgs results

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Cern scientists reporting from the Large Hadron Collider (LHC) have claimed the discovery of a new particle consistent with the Higgs boson.

The particle has been the subject of a 45-year hunt to explain how matter attains its mass.

Both of the Higgs boson-hunting experiments at the LHC (Atlas and CMS) see a level of certainty in their data worthy of a "discovery".

More work will be needed to be certain that what they see is a Higgs, however.

Prof Stephen Hawking tells the BBC's Pallab Ghosh the discovery has cost him $100

The results announced at Cern (European Organization for Nuclear Research), home of the LHC in Geneva, were met with loud applause and cheering.

Prof Peter Higgs, after whom the particle is named, wiped a tear from his eye as the teams finished their presentations in the Cern auditorium.

"I would like to add my congratulations to everyone involved in this achievement," he added later.

"It's really an incredible thing that it's happened in my lifetime."

Prof Stephen Hawking joined in with an opinion on a topic often discussed in hushed tones.

"This is an important result and should earn Peter Higgs the Nobel Prize," he told BBC News.

"But it is a pity in a way because the great advances in physics have come from experiments that gave results we didn't expect."

'Dramatic'

The CMS experiment team claimed they had seen a "bump" in their data corresponding to a particle weighing in at 125.3 gigaelectronvolts (GeV) - about 133 times heavier than the protons that lie at the heart of every atom.

The BBC's George Alagiah explains the Higgs boson

They claimed that by combining two data sets, they had attained a confidence level just at the "five-sigma" point - about a one-in-3.5 million chance that the signal they see would appear if there were no Higgs particle.

However, a full combination of the CMS data brings that number just back to 4.9 sigma - a one-in-two million chance.

Prof Joe Incandela, spokesman for CMS, was unequivocal: "The results are preliminary but the five-sigma signal at around 125 GeV we're seeing is dramatic. This is indeed a new particle," he told the Geneva meeting.

The Atlas experiment results were even more promising, at a slightly higher mass: "We observe in our data clear signs of a new particle, at the level of five sigma, in the mass region around 126 GeV," said Dr Fabiola Gianotti, spokeswoman for the Atlas experiment at the LHC.

Peter Higgs Peter Higgs joined three of the six theoreticians who first predicted the Higgs at the conference

Prof Rolf Heuer, director-general of Cern, commented: "As a layman I would now say I think we have it."

"We have a discovery - we have observed a new particle consistent with a Higgs boson. But which one? That remains open.

"It is a historic milestone but it is only the beginning."

Commenting on the emotions of the scientists involved in the discovery, Prof Incandela said: "It didn't really hit me emotionally until today because we have to be so focussed… but I'm super-proud."

Dr Gianotti echoed Prof Incandela's thoughts, adding: "The last few days have been extremely intense, full of work, lots of emotions."

A confirmation that this is the Higgs boson would be one of the biggest scientific discoveries of the century; the hunt for the Higgs has been compared by some physicists to the Apollo programme that reached the Moon in the 1960s.

Statistics of a 'discovery'

Swiss franc coin
  • Particle physics has an accepted definition for a "discovery": a five-sigma level of certainty
  • The number of standard deviations, or sigmas, is a measure of how unlikely it is that an experimental result is simply down to chance, in the absence of a real effect
  • Similarly, tossing a coin and getting a number of heads in a row may just be chance, rather than a sign of a "loaded" coin
  • The "three sigma" level represents about the same likelihood of tossing nine heads in a row
  • Five sigma, on the other hand, would correspond to tossing more than 21 in a row
  • Unlikely results are more probable when several experiments are carried out at once - equivalent to several people flipping coins at the same time
  • With independent confirmation by other experiments, five-sigma findings become accepted discoveries

Scientists would then have to assess whether the particle they see behaves like the version of the Higgs particle predicted by the Standard Model, the current best theory to explain how the Universe works. However, it might also be something more exotic.

All the matter we can see appears to comprise just 4% of the Universe, the rest being made up by mysterious dark matter and dark energy.

A more exotic version of the Higgs could be a bridge to understanding the 96% of the Universe that remains obscure.

Scientists will have to look at how the Higgs decays - or transforms - into other, more stable particles after being produced in collisions at the LHC.

Dr Pippa Wells, a member of the Atlas experiment, said that several of the decay paths already showed deviations from what one would expect of the Standard Model Higgs.

For example, a decay path where the Higgs transforms into two photon particles was "a bit on the high side", she explained.

These could get back into line as more statistics are added, but on the other hand, they may not.

"We're reaching into the fabric of the Universe at a level we've never done before," said Prof Incandela.

"We're on the frontier now, on the edge of a new exploration. This could be the only part of the story that's left, or we could open a whole new realm of discovery."

The Standard Model and the Higgs boson

Standard model

The Standard Model is the simplest set of ingredients - elementary particles - needed to make up the world we see in the heavens and in the laboratory

Quarks combine together to make, for example, the proton and neutron - which make up the nuclei of atoms today - though more exotic combinations were around in the Universe's early days

Leptons come in charged and uncharged versions; electrons - the most familiar charged lepton - together with quarks make up all the matter we can see; the uncharged leptons are neutrinos, which rarely interact with matter

The "force carriers" are particles whose movements are observed as familiar forces such as those behind electricity and light (electromagnetism) and radioactive decay (the weak nuclear force)

The Higgs boson came about because although the Standard Model holds together neatly, nothing requires the particles to have mass; for a fuller theory, the Higgs - or something else - must fill in that gap

Paul.Rincon-INTERNET@bbc.co.uk and follow me on Twitter

 

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  • rate this
    0

    Comment number 1465.

    OK, so a car crash in a tunnel produced strange looking metal fragments, sorry, particles. The designer of the original vehicles is faintly amused.

  • rate this
    0

    Comment number 1464.

    1444. 5arx

    Your gripe ... quite a few people have pointed out that the name "boson" means having "Bose-Einstein Statistics".Similarly, "fermion" means having "Fermi-Dirac Statistics.

    This isn't about whether it's a boson or not, it's about whether it obeys a law dreamt up by Higgs to solve a problem with the Standard Model. Bose just didn't have anything to do with that.

  • rate this
    -2

    Comment number 1463.

    Why do I get the feeling that the people who are rating down all criticism of this topic,were the boring, talentless folk who went on to get a job in local Government.

  • rate this
    0

    Comment number 1462.

    Must admit I find the contortions modern physicists go through to create a 'coherent' model are more than a little hard to accept. The underlying reality HAS to be much simpler and I strongly believe that all we are seeing are the behaviors under certain circumstances of what happen to be quite simple particles.

  • rate this
    +1

    Comment number 1461.

    1456. Big John the Red - Philip K Dick

    Just rereading 'Man in a High Castle' - true genius

    You are absolutely right. Back to the Sir Arthur Stanley Eddington quote

    " The universe is not only stranger than we imagine, it is stranger than we can imagine." (though this could be JBS Haldane apparently)

  • rate this
    +6

    Comment number 1460.

    652.empiredown
    Imagine a world with no absolute poverty,no hunger and easily preventable diseases eradicated? You can do a hell of a lot damage on the worlds worst social issues with eight billion dollars or you can spend it on some sad CERN scientist's ego trip.
    =
    World wide spending on weapons was $1.4 trillion in 2009 alone.
    I know where I would rather make some savings to relieve poverty

  • rate this
    -4

    Comment number 1459.

    Nothing I have seen or heard convinces me they have discovered anything. Despite all the precision measurements, there is still room for doubt when you have astronomical machines looking fior very very tiny things. No. I see this as nothing more than a cynical ploy for funding the esoteric pursuit of others. We cannot afford it. Period.

  • rate this
    0

    Comment number 1458.

    Keen observers of science will/would have noticed that there was a scientific break through, earlier today on this very site.
    The ten minute rule was broken several times but the moderators couldn't make themselves come to making them ( the comments) disappear..

  • rate this
    -7

    Comment number 1457.

    These physics academics need to be careful with these colliders. Less the rapture comes sooner than even the Lord planned. Scary stuff whizzin that thing around and for what really. Will it save a life..doubt it.

  • rate this
    +3

    Comment number 1456.

    I gave up reading science fiction many years ago, except for the odd leap back to read Philip K Dick and W S Gibson. I began reading books on particle physics. The real thing is 1. Far more interesting, and 2. Far more bizarre and counter intuitive than you could ever imagine.
    The great thing about today is that it closes 1 chapter and opens a dozen others.

  • rate this
    +5

    Comment number 1455.

    I think this is a typical example of an "Emperors New Clothes" story. Those who say it is all a waste of money are ridiculed when in fact an obscene amount of money is being spent on achieving nothing of any real value.
    -------------------------------

    You do realise EVERYTHING we have today is due to a small seeming "pointless" discovery.

  • rate this
    +3

    Comment number 1454.

    1437. jurassic_clark: Have a look at this:

    http://arxiv.org/pdf/0912.5189v1.pdf

    It's a paper from 2009 that predicts a Higgs at 126Gev, amongst other things. There plenty of solid evidence. After the debacle of faster than light neutrinos, scientists are being more careful about what they announce.

  • rate this
    0

    Comment number 1453.

    1431. Paul
    My wife just pointed out that I can be a sanctimonious old f*rt when I start on the second bottle of Soave

    1421. wibblecock
    You should get out more in which case you would not care or you should do like I do and drink more in which case you would not care or you could try reading the odd book e.g. DEEP DOWN THINGS by Bruce A Schumm in which case you would know enough already..!

  • rate this
    -10

    Comment number 1452.

    I think this is a typical example of an "Emperors New Clothes" story. Those who say it is all a waste of money are ridiculed when in fact an obscene amount of money is being spent on achieving nothing of any real value.

  • rate this
    -8

    Comment number 1451.

    I am so proud that the BBC HYS site deems this topic more important than anything else going on in the world today.
    Especially since they have appointed a new BBC DG.
    I heard on the news tonight that he was directly responsible for the coverage of the Queens jubilee celebrations.
    GOD HELP US!

  • rate this
    +3

    Comment number 1450.

    So can we make a time machine then?

  • rate this
    0

    Comment number 1449.

    its all lies if its not in the bible and its not less than 5,000 years old its fake.

  • rate this
    +6

    Comment number 1448.

    21. Shift That Paradigm
    10 HOURS AGO
    I don't believe this.

    Prove it.

    ----

    DUH! - They just did, that's the whole point!

  • rate this
    +1

    Comment number 1447.

    #1050 This is a collaborated discovery. 10 years of data at the Tevatron in US gave a 3 sigma agreement this week but their machine was not powerful enough to generate enough results and is now shut down. At CERN two separate detectors, ALTAS and CMS, each with independent teams of scientists, both confirm the results from 1.5 years of data - billions of experiments of individual collisions.

  • rate this
    +3

    Comment number 1446.

    1435.Texas73

    "...these really smart folks with a fancy machine discover the spark of creation on the same year Mayans predict the end of creation??..."

    You don't understand the Myan myth, its a rebirth myth not a destruction myth. The world will be reborn in 2012 not destroyed. It was a cyclic event due to an anomaly in their calenders which they tried to explain using the rebrith thing.

 

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