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Higgs Signal Gains Strength 189

Posted by Soulskill
from the higgs-hulking-out dept.
ananyo writes "Today the two main experiments at the Large Hadron Collider, the world's most powerful particle accelerator, submitted the results of their latest analyses. The new papers (here here and here) boost the case for December's announcement of a possible Higgs signal. Physicists working on the In the case of the Compact Muon Solenoid experiment, have been able to look at another possible kind of Higgs decay, and that allows them to boost their Higgs signal from 2.5 sigma to 3.1 sigma. Taken together with data from the other detector, ATLAS, Higgs' overall signal now unofficially stands at about 4.3 sigma."
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Higgs Signal Gains Strength

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  • Damn... (Score:3, Interesting)

    by zero.kalvin (1231372) on Tuesday February 07, 2012 @07:33PM (#38961121)
    Personally I wish if the higgs didn't exist, it would make things exciting ( from a scientific point of view). But if it doesn't, it would be a huge setback for particle physicist.
  • Eh? (Score:3, Interesting)

    by Anonymous Coward on Tuesday February 07, 2012 @07:35PM (#38961139)

    I left my statistics degree in my other pants... is 4.3 sigma a good thing? How many sigmas is "certainty"?

    • Re:Eh? (Score:5, Informative)

      by zero.kalvin (1231372) on Tuesday February 07, 2012 @07:39PM (#38961185)
      Certainty ? from a scientific point of view ? infinite! Sigmas in a way tells how probable is to get these results, the more sigmas you have means that the more improbable to get these results without invoking some other model/theory etc etc. So 4.3 is good but not good enough, we need at least 5 sigmas. (What said is not 100% correct, but a rough explanation) http://en.wikipedia.org/wiki/Standard_deviation [wikipedia.org]
      • Re:Eh? (Score:5, Insightful)

        by subreality (157447) on Wednesday February 08, 2012 @03:09AM (#38964067)

        Sigmas in a way tells how probable is to get these results

        To be pedantic, it's a measure of the probability that random chance caused these results. A 4.3 sigma result means that if you just fed white noise into the sensors, you would get a result this strong 0.001% of the time - or to put it another way, if you run the test 100,000 times with absolutely no real signal, one of them will probably have a result this good.

        The important distinction is that this is not a measure of "how likely we are right". There is a 1 in 100,000 chance that random luck caused this result, but there is also an unknown and hard to quantify possibility that our theory is wrong and some other mechanism caused this result.

    • Re:Eh? (Score:5, Informative)

      by ArAgost (853804) on Tuesday February 07, 2012 @07:44PM (#38961233) Homepage
      4.3 sigma corresponds to a confidence level of 99,998292% (credit to Wolfram|alpha). This is about as certain as death and taxes if compared to “everyday” events, but maybe it's not enough for theoretical physicists (I'm not one).
      • Re:Eh? (Score:5, Informative)

        by Anonymous Coward on Wednesday February 08, 2012 @03:10AM (#38964069)

        All this is under pure mathematician's "null-hypothesis" assumptions. That is, we have a 99.999999999% confidence level of being right, unless we are making any mistake in our set of thousands of assumptions, there is any miscalibration, any fundamental error, systematic errors, ...

        But this is not a mathematical exercise. It is a physics experiment. Knowing how the CMS/ATLAS collaboration works and how politized it is, If there is a (subtle but likely) mistake, then this number means nothing.

        The correct reading would be: "we are 99.99999999% (or whatever) sure that if we are wrong it is not due to a purely random statistic fluctuation"

        Other than that 5-sigma is a mere convention on when to trigger a press conference to declare "discovery"

      • Re:Eh? (Score:5, Funny)

        by thegarbz (1787294) on Wednesday February 08, 2012 @04:29AM (#38964397)

        This is about as certain as ... taxes ...

        Doesn't that make it 99%?

      • by macson_g (1551397)
        Well, scientist working at CERN don't pay taxes (at least they salary is untaxed and they get free health care (in Switzerland!)), so they know for sure that there is life in the remaining 0.001708%
    • Re:Eh? (Score:5, Informative)

      by olsmeister (1488789) on Tuesday February 07, 2012 @07:44PM (#38961237)
      I think they usually require 5 sigma (99.9999426697%) for it to be official.
    • Re:Eh? (Score:4, Informative)

      by mikael (484) on Tuesday February 07, 2012 @09:13PM (#38961939)

      Wikipedia has a good explanation at The 68-95-99.7 [wikipedia.org]

      How many sigmas you have is a way of summarizing how much area of the bell curve is covered or how far along to one end point the bell curve you are. Being further along means less chance of error

      From the page:
      +/- 1 sigma = 1 in 3 chances of being wrong
      +/- 2 sigma = 1 in 22
      +/- 3 sigma = 1 in 81
      +/- 4 sigma = 1 in 15,787
      +/- 5 sigma = 1 in 7,444,278
      +/- 6 sigma = 1 in 506,797,346
      +/- 7 sigma = 1 in 390,682,215,445

      • Re:Eh? (Score:5, Informative)

        by Seraphim1982 (813899) on Tuesday February 07, 2012 @09:46PM (#38962283)

        You managed to get the values for both 3 sigma, and 5 sigma wrong
        +/- 3 sigma = 1 in 370 (which is what clued me into them being wrong, 1/81 + 0.997 isn't close to 1)
        +/- 5 sigma = 1 in 1,744,278

      • Re:Eh? (Score:4, Informative)

        by epine (68316) on Tuesday February 07, 2012 @10:22PM (#38962555)

        This dialog is a bit of a mess, but makes some good points: Taleb on Antifragility [econtalk.org]

        These talks come with very loose transcripts. Here's the key passage at length as I shamelessly promote Taleb's upcoming book Antifragility [fooledbyrandomness.com], through I'm already certain I only agree with two-thirds of what he is putting forth (emphasis mine):

        It's because of convexity effects, because small probability is very convex to error. [] Take the Gaussian distribution. And actually in a separate paper I finally proved something that has taken me three years. Take a very thin-tailed distribution such as the Gaussian. Thin-tailed, the normal distribution. You have two inputs, one of which is standard deviation. Standard deviation is very much your error. Now, if you take a remote event, say, 6, 7, 8 sigmas, you increase the standard deviation away from the mean; you increase the sigma by 10%, the probability of that is multiplied by several thousand, several million, several billion, several trillions. So, what you have, you have nonlinearity of remote events to sigma, to the standard deviation of the distribution. And that, in fact if you have uncertainty, the smallest uncertainty you have in the estimation of the standard deviation, the higher the small probability becomes and at the same time, the bigger the mistake you are going to have about the small probability. So, in other words, most of the uncertainty in parameterizing the model, most of the tails. So, you take an event like Fukushima, you see, where they said it should happen every million years; you perturbate probabilities a little bit and one in a million becomes one in thirty. Or the financial crisis. Or anything.

        Some of those sigmas are model guards, not actual certainty.

        • by mikael (484)

          He sounds like the kind of person who is well on he way to making a functioning "improbabilty drive" (HHTTG) - He just needs to cut back a little on the caffeine and find a way of using the Brownian motion in a spare cup of coffee as a source of true randomness.

          "Just because something has an exceedingly small probability of not happening, is no guarantee that it won't happen."

          Some time ago, there a was a small-town church that held an annual throw-six-dice competition for charity. Pay for some throws, throw

    • Re:Eh? (Score:5, Funny)

      by Waffle Iron (339739) on Tuesday February 07, 2012 @10:22PM (#38962545)

      I left my statistics degree in my other pants... is 4.3 sigma a good thing? How many sigmas is "certainty"?

      It's not good enough. They've got a good way to go before they achieve Six Sigma.

      To make that goal, these scientists should probably go on a retreat, spend some time on team building exercises, and practice dynamic solution strategies, so that they can build up the synergies they need to deliver agile, customer-facing world class results that deliver a genuine Six Sigma experience.

      • To make that goal, these scientists should probably go on a retreat, spend some time on team building exercises, and practice dynamic solution strategies, so that they can build up the synergies they need to deliver agile, customer-facing world class results that deliver a genuine Six Sigma experience.

        Fuck everything, we're doing Seven Sigmas [theonion.com]

      • by lennier (44736)

        To make that goal, these scientists should probably go on a retreat, spend some time on team building exercises, and practice dynamic solution strategies, so that they can build up the synergies they need to deliver agile, customer-facing world class results that deliver a genuine Six Sigma experience.

        A customer-facing giant accelerated relativistic particle ray, eh? I like the cut of your jib!

  • 12/21/2012 (Score:5, Funny)

    by bryan1945 (301828) on Tuesday February 07, 2012 @07:37PM (#38961159) Journal

    Full blown Higgs signal. And the world will turn inside out and we will become Mole People and mocked by a future human and his 2 robot friends.

  • by slew (2918) on Tuesday February 07, 2012 @07:37PM (#38961165)

    Apparently, the superbowl coin toss "experiment" has generated nearly as large a statistical anomaly... http://blogs.discovermagazine.com/cosmicvariance/2012/02/04/a-3-8-sigma-anomaly/ [discovermagazine.com]

    Right now they are sorting through the math on old experimental data.

    I'm sure they are waiting for at least 6 sigma to acutally claim anything...

    • by treeves (963993)

      Motorola and GE had six sigma a long time ago. They should have just asked.

    • by timeOday (582209) on Tuesday February 07, 2012 @08:43PM (#38961709)

      Apparently, the superbowl coin toss "experiment" has generated nearly as large a statistical anomaly...

      Not really, because that was only "predicted" after it occurred. That's cheating. In other words, if you sift through millions of events discarding all the "likely" ones (such as coin tosses in other sports, or regular season NFL games, that didn't show any consistency), it is extremely likely you'll eventually find an "unlikely" one.

      In contrast, the criteria for detecting the Higgs Boson were set ahead of time.

      By the way, the NFC lost the coin toss last Sunday.

      • by BitterOak (537666)

        Apparently, the superbowl coin toss "experiment" has generated nearly as large a statistical anomaly...

        Not really, because that was only "predicted" after it occurred. That's cheating. In other words, if you sift through millions of events discarding all the "likely" ones (such as coin tosses in other sports, or regular season NFL games, that didn't show any consistency), it is extremely likely you'll eventually find an "unlikely" one.

        In contrast, the criteria for detecting the Higgs Boson were set ahead of time.

        Not entirely, because there was no specific prediction for the mass. There were upper and lower mass limits on the Higgs set by theory, but not an actual prediction. So, if you scan a mass histogram looking for a bump and then find one, you can't simply ask how many sigma it is above the background and translate that to a 99.99... whatever percent probability. That's why they're hoping for a five or six sigma signal before they say anything conclusive, despite the fact that four sigma is well above 99% p

        • by timeOday (582209)
          Hmm, in an ideal world, a reported sigma value should include those types of considerations. (Basically, factoring in how many different hypothesis were tested.) It can be tricky, but you would expect such high-profile science to be top notch. After all, to determine you need 5 or 6 sigmas to exceed 99% probability (which is really just an inconsistent usage of terminology), you still have to perform the same calculation. (Otherwise, how do they know they don't need, say, 8 sigmas in the way they're cal
          • by BitterOak (537666)

            Hmm, in an ideal world, a reported sigma value should include those types of considerations. (Basically, factoring in how many different hypothesis were tested.) It can be tricky, but you would expect such high-profile science to be top notch.

            It is high profile science, but these "sigma" numbers are in informal way of reporting the size of the signal. In the final paper, they'll report masses and production rates with proper error bars, taking into account all statistical factors. The final published paper won't say "Hey, we have a six sigma signal!", it will say the mass of the Higgs is xxx ± yyy GeV/c^2, etc., and a mass histogram will also be shown, as well as information on the mass window searched, etc.

      • How are you going to toss a coin if NFC payments are going to replace coins? Throw up an iPhone and if the screen brakes, it's tails?
    • That article selected 14 out of 45 coin tosses and then calculated odds but because of the selection the odds calculation is in error.
    • by mikael (484)

      They say it is impossible on how to bias a coin to one side or another (the centre of gravity would only move closer to one side or another). One commenter posts a way of tossing a coin even if such a bias were possible (using HT vs TH).

    • Dear God. I'll make Sean Carrol a deal: I will never again talk in public about physics, as long as he agrees never again to talk in public about statistics. The sheer badness of that post makes my head want to go all splodey.

  • Only the first step (Score:3, Interesting)

    by Anonymous Coward on Tuesday February 07, 2012 @07:48PM (#38961279)

    This is only the first step. What the data suggests is that there's probably a particle there -- however, the higgs has several important properties that are impossible to measure with this dataset yet -- like its spin0 property. Chances are though, that because of how this data fits in with the higgs predicted mass, it really is the higgs.

    • by sweetser (148397)
      An excellent point. Note that there are two other channels that will indicate the spin 0 property. Those signals are so small compared to the background that it will be a few years before that issue is resolved.
  • by ScentCone (795499) on Tuesday February 07, 2012 @07:53PM (#38961305)
    So, we can detect Higgs but we can't detect multiple typos in the damn summary? Really?
  • by sexconker (1179573) on Tuesday February 07, 2012 @08:20PM (#38961511)

    Physicists working on the In the case of the Compact Muon Solenoid experiment, have been able to look at another possible kind of Higgs decay,

    Clearly, this was originally

    In the case of the Compact Muon Solenoid experiment, physicists have been able to look at another possible kind of Higgs decay,

    and someone sloppily tried to change it to

    Physicists working on the Compact Muon Solenoid experiment have been able to look at another possible kind of Higgs decay,

    but failed.

    Just fucking CTRL+C, CTRL+V - no one believes you're writing up your own summary anyway. Just plagiarise in full.

  • by GodfatherofSoul (174979) on Tuesday February 07, 2012 @08:27PM (#38961559)

    I'll be standing at the gates of the Playboy Mansion waiting for an avalanche of apocalypse sex

  • by PPH (736903) on Tuesday February 07, 2012 @08:30PM (#38961587)

    Forget all that sigma stuff. We want Las Vegas bookmaker's odds.

  • posting to undo accidental bad moderation

  • They will probably attribute the increase in Higg's signal strength due to global warming.

"And do you think (fop that I am) that I could be the Scarlet Pumpernickel?" -- Looney Tunes, The Scarlet Pumpernickel (1950, Chuck Jones)

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