back to article CERN data explains how Higgs heavies other matter

Ever since the putative discovery of the Higgs boson in 2011, one of the next-big-thing searches in physics has been to confirm the mechanism by which the exotic particle imparts mass to other particles. Now, a team led by boffins from Brookhaven National Laboratory think they've contrived just such a test. In work conducted …

  1. RobHib
    Thumb Up

    Look forward to the 13 TeV setup results.

    I'm looking forward to reading reports say late 2016 when the dust settles on the 13 TeV setup results. As is always with science, additional research and time to digest results is necessary and prudent.

  2. hplasm Silver badge
    Boffin

    "...the outcomes of 20.3 inverse femtobarns"

    Marvelous banter!

    1. James 36

      Re: "...the outcomes of 20.3 inverse femtobarns"

      I think a femtobarn was for sale in kensington for £54,000,

      suitable for a professional couple apparently

      mines the one with the mass giving pockets....ta

  3. A Non e-mouse Silver badge

    The 13 TeV setup will ... collect as much as 150 times as much data as the previous 8 TeV configuration.

    Why will the 13TeV setup collect more data? Are the detectors upgraded? Will it run longer than the 8TeV setup did?

    1. Rich 11 Silver badge

      It will create a greater number of more energetic collisions.

  4. willi0000000

    is there any way to reverse this process and lose mass?

    [asking for a friend . . . of course]

  5. Andy E

    Why is it so hard to see?

    Given that just about everything has mass, why is the Higgs so hard to detect?

    1. Khaptain Silver badge

      Re: Why is it so hard to see?

      I gave up after the first couple of paragraphs.

      Why is it so hard to see?

      1. 0laf Silver badge
        Boffin

        Re: Why is it so hard to see?

        Yup after a couple of paragraphs my brain threw in the towel and waked out for a breath of fresh air.

        And I thought I knew a little bit about quantum physics.

      2. aBloke FromEarth

        Re: Why is it so hard to see?

        As I think I understood the article...

        When particles are smashed at the right energy level, Higg's bosons are produced. But we can't detect HBs themselves.

        However, HBs decay into other types of particles (in almost every collision it becomes a pair of quarks, and very infrequently it's other particles). The trouble is, many of the other particles in the collision *also* produce particles just like those.

        = Needle in a haystack.

        However, in 0.1% of collisions, HBs produces a pair of photons, which are what you can measure. If you add up their energy & mass it should equal the energy and mass of an HB (good old Einstein at work, there).

        IANAPP (I am not a particle physicist), so if there's anyone out there who actually understands it, please correct me!

        1. Michael Wojcik Silver badge

          Re: Why is it so hard to see?

          Huh. I thought that blog post was pretty easy going, particularly compared to reading any of the actual papers published on the subject, or, say, Lacan or Heidegger. But I think reading this stuff requires a rather specific kind of focus - it's not a matter of "are you smart enough" or anything else so simplistic.

          Anyway...

          However, in 0.1% of collisions, HBs produces a pair of photons, which are what you can measure. If you add up their energy & mass it should equal the energy and mass of an HB (good old Einstein at work, there).

          This is missing an important detail. There's a background that obscures this signal, too - lots of other stuff decaying into photon pairs. The key is that the experimenters count all the observed photon-pair decay events at each total energy level, and there are more of them at the Higgs mass level (because of those decaying Higgsies), which produces the spike in the graph shown in the blog post. So you plot number of photon-pair decay events versus their mass, and where the spike appears, that's your possible Higgs.

          (Also, photons have no rest mass, so you don't exactly "add up their energy & mass", but that's a minor quibble.)

  6. Anonymous Coward
    Anonymous Coward

    Still waiting on a grand unified theory

    Standard model at one end, General Relativity at the other. Come on boffins - stop polishing the work of those done in the last century and make some new science bitches.

    1. Anonymous Blowhard
      Happy

      Re: Still waiting on a grand unified theory

      It's OK for spectators to criticize; they're flogging their GUTs out to find one!

    2. 7

      Re: Still waiting on a grand unified theory

      Most of the effort to this end is being expended ensuring only well-funded mainstream ideas are in the running for this elusive prize. Of course Nature has proven annoyingly independent, generally refusing throughout human history to submit to the will of establishment figures hell bent on seeing their notions proven correct, and their renown/funding validated. So if Nature's notion of a true Theory of Everything requires there be some paradigm/funding shattering, expect none. Expect instead what we have had for the last half century: all provable advance made primarily using the tools developed in the first half of the 20th century. In the new physics building at a local university there are a number of famous equations etched into the walls. The newest of them is 80 years old. QED

      1. Anonymous Coward
        Anonymous Coward

        Re: Still waiting on a grand unified theory

        My point exactly.

        In a recent interview on BBC Radio 4 with Chris Llewellyn Smith - a key architect in the Standard Model admits his work is standing on the shoulders of giants, and work on the fundamental particles has basically been tinkering with the same standard model for the last 40 years....

        http://downloads.bbc.co.uk/podcasts/radio4/tls/tls_20140701-0930a.mp3

        Jump to about 8:30 if your attention span is too short for the whole interview

        "Since 1975 we knew what we know today...."

        1. Toastan Buttar

          Re: Still waiting on a grand unified theory

          "Since 1975 we knew what we know today...."

          Pish. They didn't KNOW that the Higgs existed in 1975.

          Or 1985.

          Or 1995.

          Or 2005.

  7. Stretch

    Is there an anti-higgs then?

    1. John Brookes

      @Stretch

      It is its own antiparticle - Higgs' is a real scalar field....

  8. Billa Bong

    8TeV vs 13TeV

    If at first you don't succeed.... hit it with a bigger hammer!

    1. Anonymous Coward
      Anonymous Coward

      Re: 8TeV vs 13TeV

      "hit it with a bigger hammer"

      Technically that is known as a "Birmingham screwdriver"

      1. Dan Paul

        Re: 8TeV vs 13TeV

        No, thats a Harley Davidson tool kit.

        For those who don't understand, the hypothetical H.D. toolkit consists of a 5 lb sledge hammer and a 3 foot long screwdriver. IE bigger is better, or anything smaller is just a toy.

  9. Anonymous Coward
    Anonymous Coward

    femtobarns

    nanosheds surely? They are supposed to be boffins.

    1. Dave 62

      Re: femtobarns

      Aye but these guys are big time, they've clubbed together to buy a barn.

      Begs the question, how many femtobarns are in nanoWales?

      I'd like to take this opportunity to table a motion that Barns be added to the Official El Reg Units of Measurement.

      1. This post has been deleted by its author

        1. Anonymous Coward
          Anonymous Coward

          Re: femtobarns

          A femtobarn is pretty small. I think you mean a terabarn.

          1. Michael Dunn

            Re: femtobarns @Arnaud the less

            The quote was _inverse_ femtobarns; could be pretty large!

      2. Martin Budden
        Coat

        Re: femtobarns

        I'd like to take this opportunity to table a motion that Barns be added to the Official El Reg Units of Measurement.

        Yes, the Barn should be one of the El Reg staple units. A Barnstaple.

    2. richardcox13

      Re: femtobarns

      Well according to another place (http://en.wikipedia.org/wiki/Barn_%28unit%29):

      > Other related units are […] the shed (10^(−24) b (1 yb), or 10^(−52) m^2) […]

      which makes a nanoshed really rather small indeed.

  10. Robert Helpmann?? Silver badge
    Childcatcher

    Exotic Physics

    Pleier says the interactions so far observed match the rate of W-W production and scattering predicted by Standard Model physics – which is yet another arrow-to-the-knee for more exotic physics.

    Earlier in the article, it was mentioned that "at a critical temperature the Higgs field becomes tachyonic," To me, anything becoming tachyonic would seem to be exotic.

    1. Michael Wojcik Silver badge

      Re: Exotic Physics

      To me, anything becoming tachyonic would seem to be exotic.

      Here, apparently, "tachyonic" just means "having imaginary mass"1. And that really just means that its energy is not in a stable equilibrium (it's at a local maximum rather than a local minimum), thus spontaneous symmetry breaking2 occurs, and it moves to a lower energy state. This makes it no longer tachyonic, a process called "condensation" (because the lower energy becomes a condensate of new particles).

      So it's not "exotic" in the sense of "not happening very often"; or in the sense of "gosh that's pretty weird" (relative to other stuff that happens at the quantum level); or in the sense of "the mathematics are bizarre" (because as it turns out they're not); or in the sense used in the article, which is "different from the Standard Model". It's perfectly in keeping with the SM, as I understand it.

      Of course, you can still find it "exotic" in a subjective sense.

      1A non-tachyonic field usually has complex mass, where the real part corresponds to rest mass (I think) and the imaginary part to decay rate. At least that's my understanding from browsing some of this stuff. I may be wildly incorrect. But the point is "imaginary mass" here just means "the real part is zero". This also means the field doesn't have any particle-like nature, apparently, until it condenses and becomes non-tachyonic.

      2The standard analogy here is a ball balanced on top of a perfectly symmetrical hill. Any perturbation will cause the ball to roll down the hill in some direction, which breaks the symmetry.

  11. Anonymous Coward
    Anonymous Coward

    Re: femtobarnes

    The Barn is a (very small) standard unit of measure for surface area in particle physics and is indeed referring to a joke about a uranium nucleus being "as big as a barn" - see http://en.wikipedia.org/wiki/Barn_(unit)#Etymology

    1. Martin Budden
      Thumb Up

      Re: femtobarnes

      "Other related units are the outhouse (1 μb, or 10−34 m2), the shed (10−24 b (1 yb), or 10−52 m2) and the "skilodge" (1 mb, or 10−31 m2)"

  12. cosmogoblin

    "That test yields only a 95 per cent confidence level"

    “...establishes a signal at a significance level of 3.6 sigma"

    3-sigma = 99.73% confidence. 4-sigma = 99.993%. I don't have time to check the maths but 3.6-sigma would be about 99.9% confidence, not 95%.

    What's wrong here?

  13. Anonymous Coward
    Anonymous Coward

    Tachyonic?

    So if they used enough energy on the slingshot effect they could go back beyond yesterday?

    Cool!

    (digs out his copy of ST:TOS)

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