Cern Scientists Suspect Glimpse of Higgs
Scientists may have caught their first glimpse of the elusiveHiggs boson, or "God particle", which is thought to give mass to the basic building blocks of nature.
Researchers at the Large Hadron Collider at Cern, the European particle physics lab near Geneva, announced the findings at a conference on Friday yesterday.
The world's most powerful atom smasher hunts for signs of new physics by slamming subatomic particles together at nearly the speed of light in an 18-mile round tunnel beneath the French-Swiss border.
Speaking at the meeting, teams working on two of the collider's huge detectors, Atlas and CMS, independently reported unusual bumps in their data that could be the first hints of the particle.
Physicists stressed that it was too early to know whether the signals were due to the missing particle.
Bumps that look like new discoveries can be caused by statistical fluctuations in data, flaws in computer models and other glitches, they said.
"We cannot say anything today, but clearly it's intriguing," Fabiola Gianotti, spokeswoman for the 3,000-strong Atlas team, said. She said the picture would become clearer as the groups gathered more data and combined results in the next few months. The view was shared by Guido Tonelli, spokesman for the CMS group, said more data was needed to understand whether the bumps were due to "statistical fluctuations or possible hints of a signal".
The long-sought particle was first postulated in 1964 by Peter Higgs, a physicist at Edinburgh University, in a theory that described how fundamental particles gained mass from an invisible field that pervaded the cosmos.
The field has been compared to a snowfield that clings to particles and slows them down to different extents. Light particles pass through the field swiftly as if they have skis on, while heavy particles trudge through as though walking barefoot.
The boson was nicknamed the "God particle" in 1993 by the Nobel prize-winning physicist, Leon Lederman. The monicker is detested by Higgs. "I find it embarrassing because, though I'm not a believer myself, I think it is the kind of misuse of terminology which I think might offend some people," he said.
From previous work, the Higgs boson was thought to have a mass somewhere between 114 and 185GeV (gigaelectronvolts) – one GeV is roughly equivalent to the mass of a proton, a subatomic particle found in atomic nuclei.
The Atlas team reported a Higgs-like bump in their data between 120 and 140GeV. In a later session, the CMS group announced two bumps in the same region.
Matt Strassler, a theoretical physicist at Rutgers University in New Jersey, commented on his blog: "Exciting … but far too early to be sure this is anything interesting." He added: "This is certainly something we'll be watching."
http://www.guardian.co.uk/science/2011/jul/22/cern-higgs-boson-god-particle/print
"Experiments are the only means of knowledge at our disposal. The rest is poetry, imagination." Max Planck
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Yah, both the LHC and the Tevatron have been getting data spikes in that region for months now.
What is probably worthy of consideration is that they do thousand of collisions per second and for the most part, nobody actually looks at the data directly. It is all stored in computers which are programmed to do the actual analysis and trigger an alert when expected data seems to appear. Then too, the data is not discarded. It is saved so that someone can go back and look over some portion of the data that did not generate a possible hit to see if there might be something worthy of consideration.
What they are seeing in the data is Bayesian probability. Basically, if you look at 3,000 runs and you get a single hit, that means that the probability that it is a real signal is 1:0003. If the same 3,000 runs show a hundred hits, then the odds of a real signal rise to 1:0.03. A thousand hits across 3,000 runs would give a probability of 1:0.3
Right now, they are doing runs at a variety of energies and getting small numbers of hits. As the work continues, they will narrow the range of energies to see where the hits are showing up more often until they get to a much higher probability. Actually, I picked the numbers above because this is statistical work and there will always false negative runs. However, a probability of 1:0.3 is considered to be persuasive that something is within the margin of error.
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Can someone explain me in simple terms why three quarks in a proton provide just about 10% of its mass? Where the extra mass is coming from and why do we need the Higgs boson to explain it? According to Wikipedia and my limited understanding, the extra mass comes from something called quantum chromodynamics binding energy, which is a function of strong nuclear force. This is transmitted by gluons, which are bosons, so where do we put Higgs boson in there? It's not like we can split a virtual particle like gluon and find a couple of Higgses in there.
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Well, those are not simple questions and they don't really even work together the way that you put them. So you can't really get a simple answer from them.
Even so, one important factor is the equivalence of mass and energy, the famous E=mc^2. On every level, if something is moving, then it has energy and by applying the equivalence of mass and energy, that energy is the source of the “extra” mass in QCD theory.
Now, you also need to understand that nothing can ever be thought of as not moving. Especially on the particle scale. At those levels, we find that there is a background of energy that particles are embedded in and the constant changes in that background cause all particles to experience what are known as quantum jitters.
There is not a really good way to understand that without doing all of the things that physics does on that level but you might find it helpful to think of different particles like tiny ball bearings on a table and the background energy to be like a constant vibration in the material of the table.
Another qualification is that quarks interact with themselves via the strong force. Now unlike the electrical force with plus and minus states, the strong force has three different states. When it came to be clear that scientists were going to have to come up with names for them, they picked red green and blue.
The bosons that mediate the strong force and they also have color charges but that is probably more complication than you need at this point. For a mental picture, you could think of the gluons as the links of the chains that hold the quarks together. Now there is a limit to how long those chains can be. While gluons have not mass directly, they do have energy and when a gluon chain reaches to point where it contains slightly more energy than two more quarks, well basically, the chain breaks in the middle and the excess energy converts to two more quarks. This adds additional mass to any quark/gluon system.
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The binding energy has mass, by e = mc2, ie m = e/c2. It is embodied in a 'static' force - it does not require motion.
This is the the same kind of mass that gets "converted to energy" in nuclear reactors and bombs. No electrons/neutrons/protons are lost in those reactions.
Think of it like gravitational potential energy, such as the energy stored in a hydro dam. Letting that water flow to a lower level allows that energy to be converted into another form, first mechanical energy in the turbines, then electricity and heat in the generators.
Favorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality
"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." - Sam Harris
The path to Truth lies via careful study of reality, not the dreams of our fallible minds - me
From the sublime to the ridiculous: Science -> Philosophy -> Theology
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That is, of course true Bob. However, he was asking about the interaction between quarks, thus he is asking about the strong force. Binding energy is an aspect of the weak force and several orders of magnitude too low to be of much relevance to QCD theory.
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'Binding energy' is an aspect of whatever force is binding the sub-particles of a given particle together, or particles within a composite system, such as protons and neutrons within a nucleus.
The strong force is what holds the nucleus together, I wasn't aware the weak force was involved in binding, it was originally associated with beta-decay.
One reference refers to the 'color' force binding quarks together, mediated by gluons. Which turns out to be yet another manifestation of the strong force as an aspect of QCD.
So my searches show the strong force, in one form or another is what is holding the nucleus together, and also the nucleons themselves.
Now another issue in my response, would be if the quarks have some additional energy associated with them which is not specifically associated with binding them with each other in the nucleon. Which would be an additional part of the mass.
At this point I begin to lose interest in digging further, since I am more interested in going up the hierarchy to biology and beyond, to contexts which are not reducible to or explained by the properties of the quark and sub-quark 'world'.
Favorite oxymorons: Gospel Truth, Rational Supernaturalist, Business Ethics, Christian Morality
"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." - Sam Harris
The path to Truth lies via careful study of reality, not the dreams of our fallible minds - me
From the sublime to the ridiculous: Science -> Philosophy -> Theology
I've recently read that many scientists are starting to question whether it exists. One way or another within a year or so we should know.
Enlightened Atheist, Gaming God.
As an aside, the original term Leon used for the Higgs Boson was the "goddamn" particle. This was apparently thought of as a really bad name ...
"Obviously I'm convinced of the existence of G-d. I'm equally convinced that Atheists who've led good lives will be in Olam HaBa going "How the heck did I wind up in this place?!?" while Christians who've treated people like dirt will be in some other place asking the exact same question."