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Researchers Find Evidence of How Higgs Particle Imparts Mass
brindafella (702231) writes Physicists at CERN's Large Hadron Colider (LHC) ATLAS experiment have been looking through their data, and have found enough of the extremely rare "W boson" (proton-proton) collisions that they can now declare their results: They have found how the Higgs imparts mass to other particles. From the article: "'Only about one in 100 trillion proton-proton collisions would produce one of these events,' said Marc-André Pleier, a physicist at the U.S. Department of Energy's Brookhaven National Laboratory who played a leadership role in the analysis of this result for the ATLAS collaboration. 'You need to observe many [collisions] to see if the production rate is above or on par with predictions,' Pleier said. 'We looked through billions of proton-proton collisions produced at the LHC for a signature of these events—decay products that allow us to infer like Sherlock Holmes what happened in the event.' The analysis efforts started two years ago and were carried out in particular by groups from Brookhaven, Lawrence Berkeley National Laboratory, University of Michigan, and Technische Universität Dresden, Germany."
Here's a pre-print of the paper.
I think because of the scientific method, you come at it from the other direction.
Someone did some maths. That suggests that it does give matter mass, and in doing so also predicts certain decays.
Then you look for those decays. The chances of those decays occurring completely at random in the exact way your maths predict, in any other circumstance, are immensely small. Thus - if the decays are there - it's probable that you were right.
It's like saying, we know there is a certain kind of Yeti in this forest. The maths tells us that its footsteps will look a certain way, walk so far, stay confined to this area, etc.. And when we and others go looking - eliminating all bias they can - we happen to find footsteps exactly like that, exactly where we expected, exactly how we expected.
Now it doesn't mean it IS a Yeti. It doesn't mean it's even our kind of Yeti. It just means that - from complete assumption and logical consequences of that reasoning, we happen to find exactly what we'd expect if we were right. The chances of us being wrong but something SO SIMILAR happening in the exact right place is immensely tiny and - statistically, predictable enough that you can try to eliminate it as much as possible. This is all that "99.9999%" certainty junk that you see. For things to decay in that way, we're 99.9999% certain that it is because of the original assumption and not anything else along the way (including random chance).
When you come at it, arse-backwards like that, the chances of you being wrong are small. Unless, of course, some other animal that's equally as unknown happens to completely coincidentally make the exact same footprints. In which case, that's STILL a win for maths/science. We found something out by poking around in the right places that we never knew before and - given the similarity - our maths can't have been far wrong in the first place. And we can spot the error, correct for it, and try to understand it.
Nobody is seriously saying "this is EXACTLY what we thought". They are saying, when we test under the assumptions made, the evidence of reality appears to fit this best, subject to a certain accuracy. Other hypotheses that predict similar results in the same area either don't exist (which is suggestive that you're right but still has to be proven) or have to be proved wrong in order to get close to making such statements.
The Higgs field imparts mass on particles by exchanging virtual Higgs particles with them. A real Higgs particle surfaces when the field becomes excited, but you need a lot of energy for that.
Summary and title is a bit misleading. I was eager to see what they would say about how this 'higgs boson' infers mass to other particles, but they never say anything about that, they just talk about how they found this data and how they produced the results. Maybe I missed something?
Indeed. Only a small fraction of the collision events are kept, otherwise the amount of data would be overwhelming.
From http://www.lhc-closer.es/1/3/13/0:
In particle physics, a trigger is a system that uses simple criteria to rapidly decide which events in a particle detector to keep when only a small fraction of the total can be recorded. Trigger systems are necessary due to real-world limitations in data storage capacity and rates. Since experiments are typically searching for "interesting" events (such as decays of rare particles) that occur at a relatively low rate, trigger systems are used to identify the events that should be recorded for later analysis. Current accelerators have event rates greater than 1 MHz and trigger rates that can be below 10 Hz.