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
    -1

    Comment number 1645.

    Mike Martin,
    If you care to put ego to one side and inform yourself (truthfully), you will find that the “fanatics” were a handful of rebels “who decided to go off on their own egotistical tangent”.
    .../2

  • rate this
    +1

    Comment number 1644.

    #1618 Entropic Man, #1631 fuzzy, #1638 fuzzy

    Help!
    I've opened a portal to another universe and the horrible jokes are flooding in!:)

  • rate this
    -2

    Comment number 1643.

    1627. insert_name_here "Gone are our worries about how to manage, on a decreasing income, to live. I'll be voting LHC next time around."
    ~
    LoL I won't. From where I can see, it's as detached from reality as the bankers are.
    Many things are set to change. The banks & contemporary 'physics' are far from immune.
    BTW, no one answers my Qs on quarks, gluons, et c., ref 1612 & more. I wonder why. Not.

  • rate this
    -1

    Comment number 1642.

    I am with the entire scientific community on this on! Today is just cause to celebrate! You've just found out that the God particle/Higgs boson is entirely predictable! This means that your life is entirely predictable! That you are expected to live or otherwise is decided by this one particle! Are you the entirely predictable type?
    Very predictably, I celebrated today(lack of Independence Day)!

  • rate this
    +1

    Comment number 1641.

    @1612. Shift That Paradigm

    “Quark? Neutrino? Gluon? Messenger photon? Have they been detected singly & unambiguously?”

    No and they never will be. If the only evidence that you will accept is being able to pick one up with a microscopic pair of tweezers, you will remain unconvinced. Quantum physics doesn’t work that way and, in 400 characters, I can’t even begin to explain how it does.

  • rate this
    -1

    Comment number 1640.

    A lowly ape sitting on a spinning speck of rock in space imagined the Higgs-Boson 48 years ago. And now it's been found in reality. Such leaps forward show how deceptively simple the Universe is, and in turn how God is utterly defunct. For why is the Universe 'like clock work' as Newton noted? We shall find that there is no infinite complexity, only infinite simplicity.

  • rate this
    0

    Comment number 1639.

    1566 Matt

    Matt you insult the monkey.

  • Comment number 1638.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • rate this
    +4

    Comment number 1637.

    To the waste of money brigade...
    Its never a waste to spend money.
    At the very least, it was £2billion pounds spent which entered the economy, via wages, manufacturing and service orders.
    It would have been a waste if it was burnt.

    All science and knowledge benefits the economy though. It is the backbone of manufacturing. Or would you rather still be living in the stone age?

  • rate this
    +2

    Comment number 1636.

    Am I the only one struggling with mild disappointment that the Large Hadron Collider didn't turn out to be a stargate to Alpha Centauri or a planetary sized atomic bomb?

    I'd secretly spent so long packing/practicing positions I'd like my fossils to be found in...

  • rate this
    +2

    Comment number 1635.

    A truly remarkable discovery and if this proves to be verifiable then one of the most important in the history of science. The intellectual endeavour required to construct the LHC is mind-boggling in it's complexity and engineering brilliance. It's a kind of giant microscope allowing us to penetrate into the one of the most profound mysteries our minds have been grappling for ages to comprehend.

  • rate this
    0

    Comment number 1634.

    1416 shortpulse

    Well said my friend. Without engineering, modern science could not take place. Without science, engineers would be unable to make advances in technology. A hearty Congratulations to the entire team of scientists and engineers who made this possible.

    Amazing what can be achieved when people of the world work together toward a common goal.

  • rate this
    +1

    Comment number 1633.

    1625.fatbackfour
    unfortunately it seams many just dont understand science and the fact it does not care if a theory is proved right or wrong they only are intrested in finding out which it is
    Some don't understand why if the higgs boson had been disproved it would have been even more of a relevation to science as they would have had to scrap the whole standard model of physics

  • rate this
    +2

    Comment number 1632.

    1613.Las
    massive amounts of money and prestige have been invested... So, lo behold, they did discover this miraculous "particle".

    Hmm they've been announcing this bit by bit for some time now - its hardly a rushed conspiracy job. The trouble with conspiracy theories is that peple are all but incapable of keeping a shared secret.

  • rate this
    +4

    Comment number 1631.

    1618Entropic man

    If you want theories, ask a scientist.
    If you wany probabilities ask a statistician.
    If you want certainty ask a politician.
    If you wany Truth ask a priest.
    =
    If you want evidence, ask a scientist.
    If you want to bet, ask a statistician.
    If you want waffle, ask a politician.
    If you want nonsense, ask a priest.

  • rate this
    +1

    Comment number 1630.

    1618 Entropic man - I think your message was lost somewhat there! Because I know of your posting style from other topics, I'm guessing you're commenting on the arrogance of politicians and priests that claim absolute certainty, contrasted to the cold logic of statisticians and the more modest view of the scientist who is well aware of his own ignorance.
    Perhaps being a bit ambiguous with it.

  • rate this
    +2

    Comment number 1629.

    #1623 Darren Shepperd
    #1618 was intended as satire, not genuine advice. :)
    I had my tongue so far into my cheek , it was sticking out one ear.
    Judging from the -ve ratings you weren't the only one taking it too seriously.

  • rate this
    0

    Comment number 1628.

    It has no forseeable practical value! ... It isn't meant to, it may have value in the future, the point is to discover thigns about the way the universe is formed and held together so that this can later be manipulated, take the discovery of electrons, in itself it has no pracitcal value but by learning how to manipulate their flow we created electricity and most of the modern world.

  • rate this
    +1

    Comment number 1627.

    Phew!
    I was just about to give up all hope. Yet here it arrives, on it's shining white charger. A particle that might be like something.
    After gathering my family around me to share the news I could tell they were as relieved as me.
    Gone are our worries about how to manage, on a decreasing income, to live.
    I'll be voting LHC next time around.

  • rate this
    0

    Comment number 1626.

    Modern physics certainly is exciting, the picture we see being tantalisingly close to explaining everything.
    My love for discovery took me to work at CERN in the seventies!
    I still love discovery, the universe is a wonderful place. May we continue to learn and value what we learn.

 

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