Slashdot Mirror

← Back to Stories (view on slashdot.org)

Fresh Evidence Supports Higgs Boson Discovery

Posted by samzenpus on from the look-what-we-found dept.

An anonymous reader writes Researchers at CERN have discovered the first evidence for the direct decay of the Higgs boson into fermions, a strong indication that the particle found two years ago is the Higgs boson. From the article: "Assistant professor of physics at MIT and leader of the international effort, Markus Klute, said that his team was trying to establish if the particle that was discovered in 2012 was really consistent with the Higgs boson that was found in the Standard Model, and not one of many Higgs bosons, or an a particle that looks like it but has a different origin." Their researchers also found that the bosons also decay to fermions (fermions include all quarks and leptons) in a way that is consistent with the Standard Model Higgs. 'We have now established the main characteristics of this new particle, in its coupling to fermions and to bosons, and its spin-parity structure; all of these things are consistent with the Standard Model,' Klute says." CERN has also announced the LHC restart schedule.

42 comments

  1. /. wins this round by turkeydance · · Score: 1, Troll

    this is news for nerds for real....if it really is, that is. never know with the Standard Model orthodoxy.

    1. Re:/. wins this round by StripedCow · · Score: 1

      Even if the discovery is for real, this is _not_ news for nerds.
      They have just discovered what has been there all along, for billions of years.

      Now, what to _do_ with this discovery, that's the real nerdy part.

      --
      If Pandora's box is destined to be opened, *I* want to be the one to open it.
  2. Type 13 by jfdavis668 · · Score: 2

    Well, I guess Earth isn't a type 13 planet after all.

    1. Re:Type 13 by Anonymous Coward · · Score: 0

      Don't want to have slashdot beta so close to me! NOOOOO!!!

  3. More than one Higgs Boson? by timrod · · Score: 4, Interesting

    Here's what I don't understand, which is probably because I wasn't a physics major.

    I thought the idea behind the Higgs Boson was this one particle that explained away a lot of different things in physics if you inserted it into the equation, but that no one could actually prove existed - and thus the idea was that if it did exist, physics was validated and if not, they'd be going back to the drawing board.

    The way I've always heard it talked about, there was only one Higgs boson that either existed or did not exist - anything different wouldn't be considered a Higgs boson, but a different particle altogether since there was a specific definition as to what constituted a Higgs boson.

    So, how can there be more than one Higgs boson?

    1. Re:More than one Higgs Boson? by Anonymous Coward · · Score: 1

      since there was a specific definition as to what constituted a Higgs boson

      The definition isn't specific. For example it doesn't specify the mass.

    2. Re:More than one Higgs Boson? by AchilleTalon · · Score: 5, Informative

      In the energy range of the LHC the Higgs boson is not the only new particle that could have been discovered. You cannot automatically tag the particle a Higgs boson unless you observe and measure some of its characteristics, which is exactly what is done here, to prove it is actually a Higgs boson and not another exotic particle from another exotic theory. The Standard Model is far to be the only existing one and the LHC is also seeking for physics beyond the Standard Model. The few characteristics originally observed from the early announcement were insufficient to make certain it was a Higgs boson, that's why it was originally called a Higgs-like particle.

      --
      Achille Talon
      Hop!
    3. Re:More than one Higgs Boson? by Anonymous Coward · · Score: 0

      They're trying to find "a higgs boson" to determine if there is a "higgs field" through space.
      And trying to tell one extremly tiny particle that oinly exists for minute amount of time, is difficult..

    4. Re:More than one Higgs Boson? by Charliemopps · · Score: 4, Informative

      It depends on the model. In "The standard model" there is one Higgs boson. There are other models where there are more. This is a strong confirmation of the Standard model which is where the real story is. A lot of models for the universe just died. When the LHC restarts we should get some really interesting data.

    5. Re:More than one Higgs Boson? by Anonymous Coward · · Score: 0

      I am in your boat, stupid question, if it decays into quarks and leptons which already had been found, why has this particle been so hard to find? I was assuming the Higgs was smaller or at least under the quark/lepton scale...

    6. Re:More than one Higgs Boson? by craklyn · · Score: 3, Informative

      One cannot measure a Higgs boson directly since it promptly decays. Consequently, it's necessary to identify particles it decays into.

      Quarks and leptons are measurable objects in detectors, but quarks and leptons are also created in other processes that are much more likely to occur. This creates a large background which must be subtracted from the Higgs boson decay's signal. These channels are harder to measure due to the significant background.

      The other channels of Higgs decay that were identified first included Higgs bosons decaying into gauge bosons. The probability of this occuring is not so large, but such decays can result in 4 leptons (e.g. two electrons plus two muons, four electrons, or four muons), and that has a very clean, measurable signal with very low background.

    7. Re:More than one Higgs Boson? by craklyn · · Score: 5, Informative

      This is kind of like if you're walking through the woods and you discover piles of bear shit as you go. The bear shit implies there's at least one bear in the woods, but it does not preclude that there could be multiple bears responsible for it.

      The Higgs field is a solution to the question of why some fundamental particles have mass. Theoretically, such a field is well-motivated. If such a field exists, it implies there is at least one massive, spin-zero particle that we have decided to call the Higgs boson. There are various extensions to our models, such as the so-called "Higgs two-doublet model" which SUSY extends, where more than one Higgs exists.

    8. Re:More than one Higgs Boson? by cciechad · · Score: 3, Informative

      See this. Best explanation on how the higgs particle may vary. http://profmattstrassler.com/a...

      --
      https://www.fsf.org/associate/support_freedom
    9. Re:More than one Higgs Boson? by Anonymous Coward · · Score: 0

      Your post doesn't answer the parent's question "how can there be more than one Higgs boson?"

    10. Re:More than one Higgs Boson? by Anonymous Coward · · Score: 1

      If this Higgs boson does exist with the appropriate characteristics, then the Standard model is not invalidated. Not is validated. Not proven true, just not proven false.

    11. Re:More than one Higgs Boson? by pjt33 · · Score: 2

      FWIW, the mass of the Higgs is less than that of the top quark, but considerably more than that of the other quarks.

    12. Re:More than one Higgs Boson? by AchilleTalon · · Score: 1

      No, because the OP's question was rather than why all these caution around the identity of this boson if there is only one Higgs. However, he didn't suspect the question doesn't make sense neither if this Higgs boson is another Higgs boson instead of the first Higgs boson, at the end it is still a Higgs boson anyway. The reason the physicists were so cautious about the identity of the particle is not because it could be another Higgs boson, it is because it could be another particle predicted by another theory which would instead of confirming the Standard Model rather than debunked it.

      --
      Achille Talon
      Hop!
    13. Re:More than one Higgs Boson? by Anonymous Coward · · Score: 0

      No his question was "how can there be more than one Higgs boson?" This is orthogonal to the LHC experiment.

    14. Re:More than one Higgs Boson? by azav · · Score: 2

      OK. So what makes these particles if they instantly decay? If they instantly decay, then there must be a Higgs factory all over the universe rapidly churning these babies out

      If the Higgs decays, then how do the bosons keep their mass when it is gone?

      --
      - Zav - Imagine a Beowulf cluster of insensitive clods...
    15. Re:More than one Higgs Boson? by pjt33 · · Score: 2

      I'm not a real physicist, but by coincidence I happen to be reading a good book about the LHC and the Higgs field at the moment. (The Particle at the End of the Universe, by Sean Carroll: highly recommended). The explanation given, as I understand it, is that what really matters isn't particles but fields: particles are what we perceive when a field has a concentration of energy in one* place. (* Except that we're talking quantum mechanics here, so the Gabor-Heisenberg-Weyl uncertainty principle applies).

    16. Re:More than one Higgs Boson? by Anonymous Coward · · Score: 0

      OK. So what makes these particles if they instantly decay?

      They don't instantly decay, they decay on a very short time scale. The result is a bound state, and that is part of what has properties that can be measured. If it was just particles passing through each other, you wouldn't see anything different than any other collision in something like LHC. But since there is a bound state, you will see a "bump" in various plots versus energy, because something happens there that corresponds to the energy needed to create the mass of the bound state, in addition to impacting the exact decay parts you see coming out. This isn't specific to the Higgs boson, as there are a lot of other particles that decay in very short times to be observed, but had been discovered by tracking their decay products in particle accelerators.

      If they instantly decay, then there must be a Higgs factory all over the universe rapidly churning these babies out

      This doesn't quite follow, as they take quite a lot of energy to form. And not every interaction of the right amount of energy will produce one, only a small fraction. The amount of particles in the universe interacting with more than a couple hundred GeV of energy to spare per reaction is quite small compared to more mundane interactions (consider center of the Sun it is on the order of several keV, and room temperature is about 0.025 eV). It is also part of why it hasn't been found earlier, as only a small fraction of reactions with the necessary energy will react that way, as there is a lot of other stuff that can be created, much of which is "boring" junk we know about. A lot of the work of particle physics is sorting through billions of boring reactions to find a few reactions, and doing the statistics and searches in a careful way that does not amount to cherry picking data. At something like the LHC now, part of the process has to be automated since it is not capable of recording every possible interaction in the machine, as there are too many too fast, but must make a decision in a fraction of a second which should be written to disk (and it writes some randomly chosen boring ones too to double check it isn't throwing out anything good).

      If the Higgs decays, then how do the bosons keep their mass when it is gone?

      The Higgs boson is not why particles have mass. The explanation for bosons having mass is due to the Higgs field which exists and interacts without directly creating a bunch of Higgs bosons. The math behind including the existence of the Higgs field allows bosons related to the weak force to have mass. But the math also behind that field predicts that a particle related to it can be created at a certain energy. You could call such things a "fudge factor" if you want to give such bosons mass as observed, but it had an actual predictive impact the math involved and so was still science. There were alternatives that could create that mass, but they had bigger impacts or made less subtle changes to predictions, either being ruled out when their predictions were not seen, or were predicting something like several different Higgs bosons.

    17. Re:More than one Higgs Boson? by radtea · · Score: 3, Informative

      So, how can there be more than one Higgs boson?

      Physicists have a funny way of talking about theoretical entities, particularly these days when theory almost always leads experiment. We have years or decades to talk about theoretical entities, and that leads to a strange nomenclature.

      "The Higgs" is actually a class of particles. In the "bare" electro-weak theory none of the particles have masses. The only way to give them mass is to break one of the internal symmetries of the theory, and one "natural" way of doing that was invented by Peter Higgs and others in the form of a massive scalar field that takes on a non-zero vacuum expectation value as energy decreases (this is the famous "Mexican hat" potential.)

      Suppose we arrived on Earth from Mars and were observing the inhabitants, and we wondered how emergency vehicles would get through busy traffic. One of our number--call it Sggih--theorizes that humans, being visually-oriented, might use a flashing light to warn motorists of an emergency vehicle. Others might elaborate on this and suggest that both a flashing light and a loud noise would be use. All of these types of local warning mechanisms might go under the name of Sggih, with the original one being the "minimal Sggih mechanism" and the other ones going under different names.

      In the meantime, there are those who think that humans are telepathic, or use radios, or some other non-local signalling mechanism.

      Then one day in the course of observation a Martian--and let's say Martians are deaf, the air being so thin there--sees an emergency vehicle with a flashing light on top zipping through traffic. Horray! The Sggih mechanism is correct! At least probably... it may be that wasn't an emergency vehicle but some kind of advertising stunt. And if it is the Sggih, which one is it? Further research is required to determine if humans use the minimal Sggih mechanism or one of the more complex elaborations...

      This work is in the vein of that further research, and the outcome strongly suggests that of the various theoretical possibilities, nature is actually using the minimal Higgs and that is what has been seen, rather than some unexpected but similar exotic particle.

      All of this is good news for those of us who are unenthused by supersymmetry and other more-or-less exotic extensions to the Standard Model.

      --
      Blasphemy is a human right. Blasphemophobia kills.
    18. Re:More than one Higgs Boson? by vanzilar8378 · · Score: 1

      IMHO, it goes back to the old discovery of Muons and then Pions and when some physicists were convinced these two particles (one and then the other) were carrier bosons of the Strong Force. (Look up Yukawa particle) Muons turned out to be just another flavor of lepton and Pions were something entirely two (quark- anti-quark pairs) which were totally unexpected but fit the math perfectly as a Strong Force mediator particle at the time. (if I recall). This and other debacles of the past led physicists to be more cautious when detecting a particle to make sure it has all the right properties (aka spin and decays) before being sure they found what they think. Now this doesn't meant we aren't in a for surprises later, but at least they covered their bases here and checked as many decays and properties as they can. IE: http://puhep1.princeton.edu/~m... This are just two of those epic epic stories of running down the wrong path, but finding out some really great things.

  4. Re:The science is not settled on this. by Anonymous Coward · · Score: 0

    "Being an independent thinking skeptic..." Sure you are.

  5. Re:The science is not settled on this. by jythie · · Score: 2

    More evidence supporting something does not necessarily mean the issue is 'settled', but it does add weight to the interoperation and puts an increased burden on detractors to defend their position.

  6. Re:The science is not settled on this. by Anonymous Coward · · Score: 0

    Being an independent thinking skeptic, I don't think the science has been settled on whether or not the Higgs has actually been found. They may have found *something*, but there is nothing that definitively established in my mind whether it was in fact the Higgs or something else altogether. This new "evidence" does not change that.

    It's not up to you.

  7. link by HybridST · · Score: 4, Informative

    There was a link to a paper in phys.org's coverage yesterday. I read the coverage but I haven't had time to check the paper out.

    The story:
    m.phys.org/news/2014-06-evidence-higgs-boson-fermions.html

    The paper:
    http://www.nature.com/nphys/jo...

    --
    Ever notice that Cobra Commander sounds an awful lot like Star scream?
  8. This sounds like good news. by hey! · · Score: 1

    Of course you could replace the particles mentioned in the article with names from my kids' Pokemon decks and it would be just as meaningful to me, but I'm still taking it. Good news is hard to come by.

    --
    Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
  9. Re:The science is not settled on this. by HybridST · · Score: 5, Interesting

    Undergrad so take this with a grain of salt.

    They found something that looks like a higgs, smells like a higgs, and even quacks like a higgs while looking in the higgs-pond. They, afaict, have not yet measured its quantum-spin as being zero which would confirm it's indeed a higgs.

    If the higgs-like object that was discovered is truly A higgs, it may or may not be THE higgs of the standard model. The newly discovered decay channel of the higgs-like object seems to point toward the standard model and a few other frameworks which others here know in far greater detail than I.

    Now they need to measure the spin...

    --
    Ever notice that Cobra Commander sounds an awful lot like Star scream?
  10. Re:The science is not settled on this. by invid · · Score: 1

    How about we call it a Higgoid object.

    --
    The Moore-Murphy Law: The number of things that will go wrong will double every 2 years.
  11. So where is the time machine? by Anonymous Coward · · Score: 0

    This Higgs Boson thingy was supposed to change everything, yet I'm still here typing away at Slashdot wasting my life! What gives!!!

  12. Re:The science is not settled on this. by HybridST · · Score: 1

    We could call it whatever we like but "higgsoid object"

    www.google.com/search?q=higgsoid+object&client=ms-opera-mini-iphone&channel=new&gws_rd=cr&hl=en&sa=X&&as_q&nfpr=1&spell

    has no search results whereas "higgs-like object"

    www.google.com/m?q=higgs-like+object&client=ms-opera-mini-iphone&channel=new

    returns useful results. That's close to the term the popular media ascribed to the phenomenon when it was discovered and is close enough to the terminology in the journals to find the scientific papers involved without much extra effort.

    Your call as to what you would like to call it though.

    --
    Ever notice that Cobra Commander sounds an awful lot like Star scream?
  13. Re:The science is not settled on this. by Anonymous Coward · · Score: 0

    I suppose you're a fan of autodynamics as well.

  14. Other stories from site... by s1d3track3D · · Score: 1

    I'm not commenting on this discovery but here are the other top stories from that site...
    1 Hyena escapes lions by hiding in an elephant
    2 Gay bears like blow jobs
    3 Indonesia bans video-sharing site Vimeo over 'porn'
    4 Top 5 worst mobile phones ever made
    5 Fresh evidence supports Higgs boson discovery

  15. So, why no anti-gravity yet? by Anonymous Coward · · Score: 0

    We're waiting!

  16. Re:The science is not settled on this. by ByteSlicer · · Score: 4, Informative

    They have strong indications that the particle is spin-0.
    In the plot, blue is the expected data for spin-0, red for spin-2. The black line is derived from measurements and nicely corresponds with the peak of spin-0.
    See also here.

  17. Re:The science is not settled on this. by HybridST · · Score: 1

    This is an interesting development. Thanks for the links.

    --
    Ever notice that Cobra Commander sounds an awful lot like Star scream?
  18. Higgs Field by lazy+genes · · Score: 0

    I really can't understand why the Higgs field is not the main issue and why it is ignored. The discovery of the Higgs field is finally leading us on the right path. I can only think that they are too scared to admit they were wrong about the standard model or maybe science only advances with funerals. I am glad to see more people commenting on it, but jeez.

    1. Re:Higgs Field by Anonymous Coward · · Score: 0

      they were wrong about the standard model

      The Higgs field is part of the Standard Model, and the results from measurements of the Higgs boson keep matching predictions made using just the vanilla Standard Model, annoying physicists that were hoping for some hints on how to fix the Standard Model as they know it is wrong because of things like neutrino oscillations.