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Rumor Sweeping World's Science Community that CERN's LHC has Detected the Higgs Boson -The "God Particle"
April 24, 2011 10:21 PM Subscribe

Rumor Sweeping World's Science Community that CERN's LHC has Detected the Higgs Boson -The "God Particle" The controversial rumor is based on what appears to be a leaked internal note from physicists at CERN's Large Hadron Collider (LHC), a 17-mile-long particle accelerator near Geneva, Switzerland. It's not certain at this point if the memo is authentic, or what the data it refers to might mean — but the note has sent the physics community into full buzz mode.
posted by Leisure_Muffin (102 comments total) 27 users marked this as a favorite

Where's your God-particle now?!

Right here. BOOM!
posted by XhaustedProphet at 10:32 PM on April 24, 2011

(please let this be real)
posted by XhaustedProphet at 10:33 PM on April 24, 2011

Hmm, I think this post is out of date. They anounced a couple days ago that they didn't find the Higgs boson but rather seem to have found some other (unexpected) particle.

Also the end of this article was kind of WTF:

According to current physics these nano black holes could not be created at the energy levels the LHC is capable of producing. They could only be created if a parallel universe actually exists, providing the extra gravitation needed to generate the nano black holes.

uhh....
posted by delmoi at 10:33 PM on April 24, 2011 [17 favorites]

The Tevatron at Fermilab is something different, delmoi.
posted by naju at 10:36 PM on April 24, 2011 [3 favorites]

They could only be created if a parallel universe actually exists, providing the extra gravitation needed to generate the nano black holes.

So this is just some sort of viral thing for Fringe?
posted by birdherder at 10:37 PM on April 24, 2011 [1 favorite]

The nerve of that Higgs guy, naming God's particle after himself.
posted by bwg at 10:38 PM on April 24, 2011 [2 favorites]

Higgs is risen! Alleluia, alleluia!
posted by orthogonality at 10:39 PM on April 24, 2011 [5 favorites]

Some one page Higgs boson explanations.
posted by StickyCarpet at 10:41 PM on April 24, 2011 [27 favorites]

Fermilab != CERN. At all.
posted by kmz at 10:42 PM on April 24, 2011

Incredibly exciting and I hope it's true. If not, I give it credit for being convincing, at least.

And I love that the Compact Muon Solenoid supposedly detected it, because that's the project I worked on as a fairly clueless summer intern at Fermilab. (The LHC was an international effort, and my department at Fermilab worked exclusively on the LHC. But otherwise, totally different.)
posted by naju at 10:46 PM on April 24, 2011 [1 favorite]

I'm glad to see the one page explanations are all written in standard sized fonts; seems like if there was ever a group who'd be able to write tiny, it'd be particle physicists.
posted by MCMikeNamara at 10:52 PM on April 24, 2011 [4 favorites]

I'm glad to see the one page explanations are all written in standard sized fonts

Furthermore, there is a powerful lack of wildly different colours, all-caps, blinking text, and previous-millenium geocities-style page design, that all combines to lend this possible physics breakthrough the stern appearance of perhaps being the work of persons who are not insane.
posted by -harlequin- at 11:05 PM on April 24, 2011 [16 favorites]

...a 17-mile-long particle accelerator near Geneva...

I thought the CERN accelerator was a circle.
posted by Chocolate Pickle at 11:07 PM on April 24, 2011

It's a circle with a 17-mile circumference.
posted by kmz at 11:11 PM on April 24, 2011 [1 favorite]

(Obligatory reposting of awesome:

LHCb sees where the anitmatter's gone
ALICE looks at collisions of lead ions
CMS and ATLAS are two of kind:
They're looking for whatever new particles they can find)
posted by -harlequin- at 11:13 PM on April 24, 2011 [3 favorites]

I think the article posted has a big error? The actual (alleged) internal memo is posted, and then there's an old article about detecting quark-gluon plasma after that.
posted by naju at 11:17 PM on April 24, 2011

So the upshot is that the Higgs Boson is now traveling back in time to forge memos and fake evidence to throw us off the trail instead of just trying to destroy the LHC.

Will the Boson stop at nothing to prevent us from finding it? We have to destroy is before it destroys us.
posted by Ad hominem at 11:25 PM on April 24, 2011 [12 favorites]

So this is just some sort of viral thing for Fringe?

HL Ep3 ARG.
posted by Artw at 11:40 PM on April 24, 2011 [9 favorites]

I thought that other guy just solved gravity.
posted by klangklangston at 11:41 PM on April 24, 2011

The Higgs boson doesn't really have anything to do with gravity.
posted by teraflop at 11:44 PM on April 24, 2011

As for it being the Higgs, here's a pretty thorough beatdown of that idea.

Pity. I'd love for us to have something definitive either way.
posted by Ryvar at 11:45 PM on April 24, 2011

HL Ep3 ARG.
posted by Artw at 11:40 PM on April 24 [+] [!]

Gesundheit!
posted by gc at 11:46 PM on April 24, 2011 [1 favorite]

Nothing to do with gravity, eh? I don't think we know quite enough about gravity to say that quite yet.

We think mass is a side-effect of particles interacting with Higgs field, and energy (photons) is a side-effect of particles interacting with electromagnetic field. Relating them we have gravity, which seems to be a side-effect of mass in the presence of space: Any presence of mass (particles interacting with Higgs field) changes the geometry of space itself. The idea of quantum entanglement of photons over any arbitrary distance sounds a lot like the idea of gravitation over any arbitrary distance (remember, as I wag my finger I move you, the moon, the sun and everything else in the universe a little tiny bit). Accelerating any mass to the speed of a photon (through space) seems to require a nearly-infinite amount of energy. The relationships are interesting, though the formal (mathematical) analysis gets awfully ugly.

Higgs field, electromagnetic field, and gravitational field.

Finding the Higgs boson would be fun. Unifying the fields would be, literally, awesome.
posted by anarch at 11:58 PM on April 24, 2011 [6 favorites]

Someone with the username of 'Higgs Boson' needs to log in and post a comment asking: "hey guys, what's going on?"
posted by TwelveTwo at 12:18 AM on April 25, 2011 [2 favorites]

I think the article posted has a big error? The actual (alleged) internal memo is posted, and then there's an old article about detecting quark-gluon plasma after that.

this blog post explains it a little better, and this one (linked from the other) goes into more detail.
posted by delmoi at 12:19 AM on April 25, 2011

Free keywords Diphoton ; Resonance ; EWEAK ; HIGGS ; SUSY ; EXOTICS ; EGAMMA

Those all sound like they could be usernames of MeFites
posted by MattMangels at 12:29 AM on April 25, 2011

Hmm, I was reading through the "One page explanation of the Higgs Boson" and this one made the most sense to me, it was also totally different since it talked about having a lattice of Higgs Bosons in empty space
posted by delmoi at 12:41 AM on April 25, 2011

If the LHC physicists emerge from the Alps with a set of stone tablets inscribed with "I am the Higgs Boson, your God Particle. You shall have no other particles before me..." we'll know the rumors are true.
posted by amyms at 1:49 AM on April 25, 2011 [1 favorite]

If the Higgs Boson is omnipotent, why would it care about other particles? Why would an omnipotent particle even care if people worship it? It's so petty. That's why I'm aparticalist.
posted by maxwelton at 3:14 AM on April 25, 2011 [3 favorites]

Yeah, these LHC webcams show some unusual activity around the site.
posted by memebake at 3:21 AM on April 25, 2011 [13 favorites]

From someone that works at CERN:

Hi there, Sorry I didn't drop in earlier, but I'm on holiday for easter.

This "potential discovery of the Higgs" is anything but I'm afraid. I've had a read of the paper, and there are a few things that are important to note here.

1: It's an ATLAS COM note, which is meant to be internal to the ATLAS experiment and has absolutely _no_ peer review. Anyone in ATLAS can write a note like this, and it could be total bullshit. The next stage in the process is to write an internal note, which is put under somewhat more scrutiny by the collaboration prior to turning it into a publication if it's considered good enough to do so

2: The person heading up this note, Ms. Wu, is famous both inside and outside ATLAS for spamming vast amounts of notes out in the hope that one of them will be of some merit. She's hell-bent on finding the Higgs in the way that Rubbia was in finding the W boson back in the day. Sometimes people sacrifice good physics for the desire to get the prize. She "found" the Higgs at the LEP experiment at 115GeV in the gamma gamma channel as well, but this discovery was ruled out then too.

3: The analysis is flaky to say the least- they don't model the background at all, and merely fit to the distribution shape. In QCD backgrounds are very important. That bump could come from anywhere, either a detector, trigger or physical effect arising from a background distribution they don't understand

4: If the bump genuinely is a particle, it is _NOT_ a standard model Higgs. They find about 30 events in the peak, which with the data we have now is much too many to be a Higgs- it would mean the number of Higgs produced is about a factor of 10 or more larger than the Standard Model allows for. We'd have seen it in the US Tevatron experiments, and maybe even at LEP if it was produced as copiously as this. What it _could_ be is something new and non-standard model. If it is that's amazing, but again it's hard to imagine something that only appears at LHC energies and not at those of the tevatron in such copious amounts

5: This has caused a massive shitstorm in ATLAS because internally everyone knows it's shit, but it leaked within about 10 minutes of being circulated internally and the press/bloggers have jumped on it like it's evidence that god exists, elvis has returned from his trip to mars, and flying pigs use antigravity to get around.

The party line from the experiment is "This is not an official ATLAS publication". The general feeling is that the backgrounds need to be understood, the analysis needs monte-carlo simulation to back it up, and that the group who produced these results should have put a lot more effort into the publication before spamming it and claiming "first post".

I should put a huge disclaimer here: I'm not a member of the ALTAS collaboration, though I do work at CERN. My speciality is not Higgs physics, so my understanding of this only comes from a general particle physics background. Any opinion I express here is my own and not for republication.
posted by ymgve at 5:23 AM on April 25, 2011 [33 favorites]

I wonder why CERN doesn't give out real time data on what they've found (or do they?) It would make things interesting
posted by delmoi at 5:33 AM on April 25, 2011

Is it possible, just possible, that one day they will discover the Higgs Boson, and that, having done so, absolutely nothing will change, and that for the rest of us, the only discernable difference is that a website will tell us that somebody has discovered a funny-named thing while the rest of us still have to get up, brush our teeth and feed the cat without so much as a mid-sized black hole in Switzerland border to explain why we're late for work?
posted by bicyclefish at 5:37 AM on April 25, 2011 [1 favorite]

2: The person heading up this note, Ms. Wu, is famous both inside and outside ATLAS for spamming vast amounts of notes out in the hope that one of them will be of some merit. She's hell-bent on finding the Higgs in the way that Rubbia was in finding the W boson back in the day. Sometimes people sacrifice good physics for the desire to get the prize. She "found" the Higgs at the LEP experiment at 115GeV in the gamma gamma channel as well, but this discovery was ruled out then too.

Really? She's not even "Dr." Wu?
posted by fourcheesemac at 5:42 AM on April 25, 2011 [3 favorites]

She's just an ordinary guy?
posted by jokeefe at 5:44 AM on April 25, 2011 [11 favorites]

Is it possible, just possible, that one day they will discover the Higgs Boson, and that, having done so, absolutely nothing will change, and that for the rest of us, the only discernable difference is that a website will tell us that somebody has discovered a funny-named thing while the rest of us still have to get up, brush our teeth and feed the cat without so much as a mid-sized black hole in Switzerland border to explain why we're late for work?

The likelihood of this is 100%.

There's no immediate practical benefit to finding the higgs boson, just as there was no immediate benefit to discovering gluons and quarks.
posted by empath at 5:48 AM on April 25, 2011

I wonder why CERN doesn't give out real time data on what they've found (or do they?) It would make things interesting

They produce more data than it would be possible to distribute. They have to do some analysis first.
posted by empath at 5:49 AM on April 25, 2011 [1 favorite]

And it's not really clear what it means to discover a higgs boson. We can't detect it directly, and it's hard to say it really exists at all, except as an abstract mathematical concept.
posted by empath at 5:50 AM on April 25, 2011

Really? She's not even "Dr." Wu?

Seems to be Sau Lan Wu, she's a professor. Here's her CV
posted by delmoi at 5:51 AM on April 25, 2011

Woo hoo! Physics posts!

I work at Fermilab, which has its own 3+sigma deviation from the SM to freak out over, and I get the impression from most people that we're suffering from exciting-rumor fatigue. Its also probable not a great thing that this internal note got leaked. I'm a theorist, and attempting to get experimentalists drunk to find out the latest rumor is one thing, but as ymgve posted above, this hasn't been cross-checked by the collaboration and could just be someone making a mistake - it happens. We physicists will just look foolish in that case (not to mention, the naive interpretation seems to be in some conflict with previous results). Regardless, if it's true, awesome, but I'm not a fan of how this is playing out.

delmoi, the reason none of the big collider experiments make their raw data public is two-fold. First, there isn't a big enough data-center on Earth to hold it (well, Google could I'm sure, but a huge part of the ATLAS and CMS planning has been building the infrastructure). Second, you (and I, and I work on this full time), couldn't make heads or tails of it. ATLAS and CMS are arguably the most complex things ever built, and it takes a huge amount of understanding of the machine in order not to make a mistake. For comparison, NASA experiments are required by law to release all their raw data after some waiting period (maybe 6 months or so). I've used it for projects, and even with much simpler experiments, screwing up systematics is a real problem.

Oh, and to anarch, one thing to remember is that the Higgs boson isn't the source of all the mass in the Universe. It isn't even the source of 0.1% of the mass in your body. Most of the mass of protons and neutrons comes from the strong interaction. Gravitational effects are important to consider, since the Higgs boson mass appears to get corrections from physics up to the Planck scale. This is one of the reasons we suspect that there must be other new physics nearby (and discoverable by the LHC); something must be preventing the Higgs from running from ~100 GeV up to 10^18 GeV.
posted by physicsmatt at 6:06 AM on April 25, 2011 [13 favorites]

I wonder why CERN doesn't give out real time data on what they've found (or do they?) It would make things interesting

I don't think things are 'found' in the sense of "Ooh look at that!" There's a huge amount of data cleaning, analysis, interpreting, parsing, etc., by teams of researchers from multiple disciplines. It takes a while. Findings tend to emerge over longer periods of time. At some point they are deemed worthy to be released. Obviously some researchers set a lower bar for this than others.
posted by carter at 6:07 AM on April 25, 2011

According to current physics these nano black holes could not be created at the energy levels the LHC is capable of producing. They could only be created if a parallel universe actually exists, providing the extra gravitation needed to generate the nano black holes.

I don't understand this claim. I would (at some level) understand "they could only be created if some unmeasured force is involved". I do not understand "they could only be created if a parallel universe actually exists".
posted by Flunkie at 6:16 AM on April 25, 2011

And to continue what carter said (and to explain the whole 3sigma, 4sigma thing), these days, new physics is discovered due to statistical fluctuations from an expected background. It used to be, you could find one event that was so clearly unusual you could say "ah, this is a new particle decaying." The LHC just has so many events, some of which are going to be normal physics that looks just like new physics.

What you do is collect as many events that may look like the type new thing you're looking for, and try to predict the background (this last part is HARD). If you have enough events, then statistical deviations should be approximately Gaussian (this is a first order approximation, but usually pretty good). So if you have N events, you expect fluctuations to be on the order of \sqrt{N}. So if you predict 100 events, then 68% percent of the time, you'll be between 90-110 (1 sigma), 95% of the time between 80 and 120 (2 sigma), and about 99.8% of the time between 70-130 (3 sigma). By convention, particle physicists say that the Standard Model is confirmed if the data supports it to 3 sigma confidence. We say we've found new physics if we have a 5 sigma deviation. The middle ground between 3-5 sigma is where we get all sorts of madness: is it new physics, is it us being unlucky, etc. The only resolution is more data, and we'll either see the deviation rise to 5 sigma, or relax back below 3.

Also, this is pure statistics. Systematic errors are another concern, unfortunately, it's hard for outsiders to know what the systematics could be, though there is a lot of cross-talk between the experimental groups and the theorists doing QCD modeling.
posted by physicsmatt at 6:19 AM on April 25, 2011 [2 favorites]

Yes, almost certainty not true -- and done in the most embarrassing way possible.

A little background. This goes back to the LEP collider work. LEP was the Large Electron-Positron collider. There was a little "something" -- probably noise, showing up in the data, at 115GeV, 1.7σ. Now, you need more on the order of 5σ to get a discovery.

They extended the run a few months, but the standard deviation didn't change with more data, and they shut LEP down -- they wanted the tunnel for the LHC, the Large Hadron Collider.

Now, time passes. LHC starts, blows up, is fixed, restarts (at half energy), accelerating beams to 3.5TeV (3.5 times the Tevatron), and (just now*) higher luminosities. However, they haven't been running very long, and the detectors at Fermilab have anywhere from 50 to 120x the integrated luminosity to look at, and now we have this memo.

At 115GeV? If the Higgs was at 115GeV, CDF and D0 would have had it bagged long ago. They're seeing signals (at least, CDF is) at 144GeV -- that *are not* the Higgs, but they can't explain what they are, so they published to get other people looking at it -- read, D0, CMS and ATLAS.

The problem -- this is the ATLAS *collaboration*. The way you spot a high energy physics paper is the first two pages are nothing but names of those on the experiment. These are huge experiments, they have a huge number of people involved, and *all* of them are putting their career behind the paper when they sign a paper from the collaboration. So the rules on what's published by the collaboration are very strict.

Someone decided to end run that, and put ATLAS in the media as discovering something that simply isn't there -- the TeV would have seen this and LEP probably would have seen it -- the event count is really very high.

Compare this to the recent 144GeV signal at CDF -- they kept it quiet, did a bunch of work to try to figure it out, and couldn't find any reason why that signal wasn't real, but also couldn't figure out what it could be -- it was *not* the Higgs, but it really did appear to be there. So, after lots of verification, the collaboration, as a whole, publishes the signal. You did not get an email from someone who knew someone who worked with someone who's daughter went to school with someone at CDF.

This is almost certainly not real, and I suspect that if they find out who leaked it, that person is going to be told to leave in no uncertain terms.

* They beat the TeV's best initial luminosity (at the CDF collision point) on April 22nd. The usual response to a record luminosity is, of course, a quench and loss of store, but I don't know if LHC "celebrated" in the usual fashion.
posted by eriko at 6:24 AM on April 25, 2011 [7 favorites]

Small black holes could only be created at the LHC if the Planck scale was a TeV (1000 GeV) rather than what it appears to be: 2 10^18 GeV. One way to do this is to have a warped extra dimension in which some particles can propagate. Particles would then be standing waves in this extra dimension. Think of waves on a wire, but the 'warp factor' (yes, thats the real term, and amazingly enough, Lisa Randall didn't get it from Star Trek) on the extra dimension causes the waves to propagate in unusual ways. To extend the analogy, if you have a guitar string that changes its density as you move along it, you have a warp factor. We see the effective Planck scale here as exponentially larger compared to what it "really is" on the other end of the extra dimension, the other "brane." I've never heard this called a parallel universe, because there's not physicsmatt living there sporting an awesome goatee, but maybe that's what the article was blathering on about (and again, science reporters, get your act together).

Anyway, Lisa Randall has a popular book on the subject "Warped Passages." Check it out if you're interested.

Also, allow me to say how much I hate the term "God Particle."
posted by physicsmatt at 6:34 AM on April 25, 2011 [3 favorites]

I don't see any reason to keep these things quiet. Just put it out there appropriately caveated and let the physics community figure it out.
posted by empath at 6:34 AM on April 25, 2011

I've never heard this called a parallel universe, because there's not physicsmatt living there sporting an awesome goatee, but maybe that's what the article was blathering on about

People get really twisted up about 'extra dimensions', but when you're actually looking at the math, it's a lot simpler than it appears. When you specify an event in space time, you need 4 numbers, the coordinates X, Y and Z space axes and the T (time) axis. Instead of X, Y and Z, call them X₁ X₂ and X₃. Then you can just keep adding more: X₄, X₅, X₆, X₇, etc.

The math isn't significantly more complicated with 10+1 dimensions than 3+1 dimensions. You barely have to change most of the formulas. It's just extra numbers you need to specify a location in space. It's not 'other universes' or anything like that, it's just extra numbers in the formula. As to what it means in the real world, though, I don't know. I have a hard time visualizing it.
posted by empath at 6:42 AM on April 25, 2011

empath, I am told by experimentalists that 3 and 4 sigma deviations occur all the time in the early stages of an analysis, before systematic effects are tracked down. Leaking these spurious signals just causes unnecessary pressure on the experimental group to release before they are ready (and believe me, I am the first person to be pushing for more data, faster). We get to see the final analysis and then get to ask questions and push for more transparency on the interesting channels. The ATLAS collaboration wants to find new physics, but they also want to be taken seriously when they do. They built the detector, they have the right to decide how they release results in order to maintain the community's confidence in their analysis chain.
posted by physicsmatt at 6:43 AM on April 25, 2011

Also, according to an AC on Slashdot, the note leaked because "someone left a copy of the note on the printer in my office building". Presumably accidentally, of course.
posted by carter at 6:43 AM on April 25, 2011

Also, allow me to say how much I hate the term "God Particle.

How do you feel about the "Oh my god" particle, then? :-)
posted by eriko at 6:47 AM on April 25, 2011

Blah blah blah. Where's my goddamn flying car?
posted by Pastabagel at 7:10 AM on April 25, 2011 [3 favorites]

I have no idea what you are all talking about, but is it ever interesting! I wish I'd had better math and science teachers in school, damn it. I swear, I learn more about math and science reading Metafilter than I ever did in 18+ years of traditional education.
posted by bitter-girl.com at 7:18 AM on April 25, 2011 [1 favorite]

bicyclefish: "Is it possible, just possible, that one day they will discover the Higgs Boson, and that, having done so, absolutely nothing will change, and that for the rest of us, the only discernable difference is that a website will tell us that somebody has discovered a funny-named thing while the rest of us still have to get up, brush our teeth and feed the cat without so much as a mid-sized black hole in Switzerland border to explain why we're late for work?"

I've got the whole not working thing down, but I wish someone had told me I needed to feed the cat. Maybe that explains why the smelly little thing just lays around all the time....
posted by Samizdata at 7:27 AM on April 25, 2011

Pastabagel: Give us a minute. We're not just banging rocks together here.
posted by The Bellman at 7:30 AM on April 25, 2011 [2 favorites]

I wonder why CERN doesn't give out real time data on what they've found (or do they?) It would make things interesting

Possibly to reduce the number of ill-informed comments posted on the web. What data would you have them give out, the terabytes of particle position information? They're in the business of physics, not generating ass-reams of data most people couldn't do anything with.
posted by yerfatma at 7:35 AM on April 25, 2011

There is an entire class of people who are, on the whole, entitled to the title "Dr." and who typically don't use it unless they're professors: lawyers. (The J.D. degree is a doctoral-level degree.)

Pardon the derail, but as a lawyer I've got to say that a JD is not a doctoral-level degree, the presence of the word 'doctor' in the word notwithstanding. First, no way in heck a JD program represents anything like the time and effort required to get an MD or a typical Ph.D. Second, in most other countries a law degree is an undergraduate degree, and the JD requires comparable effort to those undergraduate degrees. Third, there are two other law degrees in the US system: the LL.M and the SJD. The LL.M is a Master of Laws, and the SJD is a Doctor of Juridical Science. The SJD is the true terminal, doctoral degree for legal studies, although it is not very common in the US (and in fact most people in US SJD programs are from other countries).
posted by jedicus at 7:37 AM on April 25, 2011 [3 favorites]

_{Physicsmatt is my new favorite mefite.}
posted by schmod at 7:41 AM on April 25, 2011 [2 favorites]

Oh, and to anarch, one thing to remember is that the Higgs boson isn't the source of all the mass in the Universe. It isn't even the source of 0.1% of the mass in your body. Most of the mass of protons and neutrons comes from the strong interaction.

How does this work?
posted by delmoi at 7:46 AM on April 25, 2011

"Ms." and "Mr." are still perfectly valid forms of address for people who hold doctoral degrees. The insistence upon the use of "Dr." is generally a symptom of insecurity. There is an entire class of people who are, on the whole, entitled to the title "Dr." and who typically don't use it unless they're professors: lawyers. (The J.D. degree is a doctoral-level degree.)

Oh please not this again. As someone who holds a doctorate, I know this already. I was trying to be funny with the "dr. wu" comment. Sheesh.

Also, it is not always a sign of insecurity. "Dr." is often the situationally appropriate title to use in formal circumstances; it is also used widely by PhDs in various fields of clinical science.

In this case, however, the appropriate title for a reference to professional correspondence is "Professor Wu," at least in the American academy.

But really, I was joking.
posted by fourcheesemac at 7:46 AM on April 25, 2011

"When you're lost in the rain in Juarez and its Easter time too
When gravity fails and negativity don't pull you through..."
posted by storybored at 7:54 AM on April 25, 2011

How does this work?

Explanation here.

Basically, any time you have energy confined to a space, it's going to have inertia and mass. The interactions between quarks and gluons inside the proton and neutron is enough confined energy to account for most of the mass.
posted by empath at 7:56 AM on April 25, 2011

I have no idea what you are all talking about, but is it ever interesting! I wish I'd had better math and science teachers in school, damn it. I swear, I learn more about math and science reading Metafilter than I ever did in 18+ years of traditional education.

I took lots of math and science in high-school and no one taught me any particle physics (except for stuff about electrons/protons/neutrons and how they work in chemistry)

Let me see if I can summarize this based on my understanding:

The GeV/TeV numbers are a measure of energy called the Electron Volt which is the amount of energy a single electron has when it's in a 1 volt electric field. So a GeV is a billion times more energy then that. So the discussion with these numbers is whether or not the accelerators can produce particles with enough energy to separate the Higgs Bosons from other more mundane particles like protons and neutrons (I think).

Once these things smash they send out a lot of particles, so (I think) what they're trying to look at all the data that gets generated and look for 'signals' produced by the collisions.

There's a "Standard Model" for quantum physics that predicts what should happen based on what we currently know. Any deviations would be the result of stuff we haven't seen yet.

But there's background noise and stuff like that so they need to run the experiments multiple times to see what the results are. Just like doing a phone poll for a presidential election. They can't just call 10 people, you call 1000, 2000, whatever. That gives you a confidence interval about precise your measurement is.

The 3 sigma, 4 sigma stuff, I think, refers to the Standard Deviation of a statistical distribution. When you have 3 sigma you can say with 99.7% probability that something is there, with 5 sigma you can say with 99.999942% probability that something is the case. 1.645σ is 90%

I think that's what's going on anyway.

The new LHC is able to pump more particles up to higher energy then previous colliders, and that allows for people to get a sharper "image" of the collision results (again I may be wrong here)
posted by delmoi at 8:03 AM on April 25, 2011

Wait, so flying pigs don't use antigravity?
posted by vibrotronica at 8:03 AM on April 25, 2011 [1 favorite]

I wonder why CERN doesn't give out real time data on what they've found (or do they?) It would make things interesting

If you've got a few spare petabytes per year of disk space and bandwidth, they might be able to accommodate you.
posted by kmz at 8:04 AM on April 25, 2011

Any opinion I express here is my own and not for republication.

Too late.

"Ms." and "Mr." are still perfectly valid forms of address for people who hold doctoral degrees.

Especially if you want to emphasize that the person you are discrediting is a woman.
posted by Horace Rumpole at 8:06 AM on April 25, 2011 [6 favorites]

The GeV/TeV numbers are a measure of energy called the Electron Volt which is the amount of energy a single electron has when it's in a 1 volt electric field. So a GeV is a billion times more energy then that. So the discussion with these numbers is whether or not the accelerators can produce particles with enough energy to separate the Higgs Bosons from other more mundane particles like protons and neutrons (I think).

It's worth noting that what they're doing here is basically the opposite of what happens in an atomic bomb. In a nuclear blast, the goal is to convert matter into energy. What they do in particle accelerators is convert energy into matter.

You take a particle like a proton or an electron and accelerate it to near the speed of light, and then collide it with another particle going the opposite direction -- so what you have is a huge amount of energy that needs to go somewhere -- and what happens is that it creates new particles of matter (and energy) flying off in all directions. At these energies, most of the new matter created is very unstable, so it immediately 'decays' into a more stable form, and sometimes decays again, and again. By the time it gets to the detectors, normally they see fairly normal kinds of particles like photons and electrons, but based on the energy and what kinds of particles and where they came from, they can work backwards to the collision to see what kind of particles they originally came from and what energy they must have had -- and since energy = mass, what the particle's mass was.

The point of building really big accelerators is that certain particles are very massive, and so need a huge amount of energy to create. There's no reason, though, that the collisions at a certain energy level will produce exactly the particle that happens to be that mass. It just, more or less, randomly creates particles that add up to the total energy of the collision, kind of like when you get change from a store. (They might give you 3 quarters, or they might give you 75 pennies, or 7 dimes and a nickle.).

So you have to look at a huge number of collisions and add up all of the detections and when you look at the graphs, you'll see bumps in the data centered around particular energies (masses), which should correspond to particular particles. What they're looking for, as they go to higher and higher energies, is a new bump that doesn't correspond to anything they've detected before -- and ideally ones that match predictions that people have made based on various theories.
posted by empath at 8:18 AM on April 25, 2011 [3 favorites]

found it
posted by MrFTBN at 8:26 AM on April 25, 2011 [1 favorite]

Interestingly the Phonon is also a 'boson'. What's a phonon? It's a sound particle to go along with a sound wave given particle/wave duality.
posted by delmoi at 8:47 AM on April 25, 2011

There are also magnons and excitons, etc. The definition of a particle is very fuzzy.
posted by empath at 8:54 AM on April 25, 2011

I don't believe it
posted by clavdivs at 9:02 AM on April 25, 2011

At the point we're describing sounds as particles, the word particle means nothing at all.
posted by effugas at 9:06 AM on April 25, 2011

Well, phonons are often called quasi-particles, and they're only in solids. Sound in air isn't comprised of phonons.

Phonons are considered particles because sound waves in solids are quantized, just like light waves are quantized.
posted by empath at 9:10 AM on April 25, 2011

"Professor" is not interchangeable with "Dr." One means you're tenure track, the other doesn't (I realize you know that, fourcheesemac, but in physics there are a lot of PhDs that aren't tenured, especially at ATLAS. I don't know if that's standard across academia). I don't know whether Dr. Wu is a Professor. Most people don't care. For example, I get emails to Prof. physicsmatt all the time, even though I'm not; it's the default guess so that you don't offend anyone by guessing low on their position. Either way, it's very rare to bother with honorifics (in the American physics community, it's different in Japan for example). However, that doesn't mean that referring to "Ms." Wu isn't passive-aggressive bullshit that matters more because she's a woman. I'm male, so I don't really care if you call me Mr. physicsmatt, Dr. physicsmatt or "you idiot" as long as you cite my papers correctly, I have that privilege. But physics does have a real problem with how we treat women, and this sort of thing isn't helping.

delmoi, first, I got the numbers a bit wrong. The up and down quarks weigh ~2 and ~4 MeV, respectively, and the electrons weigh 0.511 MeV - all those masses are due to the Higgs field. Strangely enough, the measurement of the lightest quark masses are very uncertain, because strong interactions are a pain in the ass to untangle. The proton weighs ~980 MeV, so if you naively say 1 proton = 2 up + 1 down, you get the Higgs contributing 0.8% of the mass of a proton. The rest is due to the sea of non-perturbative gluons and quark/antiquark pairs that glom onto the 2 up/1 down quarks (the 'valence' quarks).

As to why we say the Higgs creates mass.... ok, let's get into that. There will be a quiz later.

If you check the last thread I commented on, I said that mass is a field interacting with itself, telling you how much energy you need to spend to drag an excitation out of the background field. The amazing thing is that, of all the Standard Model matter fields (the quarks and the leptons), none of them can have a mass term. The problem is that the Standard Model fields are "chiral:" they have a handedness, and the right-handed up quark (for example) is a DIFFERENT field from the left-handed up quark - one has hypercharge +2/3 and the other +1/6, for example. A mass term would have to tie the left- and right-handed pieces together, and they can't, since the quantum numbers of these fields aren't compatible. To see why this matters, remember that a massive particle travels slower than light. If you have something spinning clockwise (call that right-handed), and you run past it and look back, it's now spinning anti-clockwise (call that left-handed, or widdershins if you're feeling old school). So mass terms for spinning particles must allow a left-handed thing to become right handed (my theory must allow me to work in any frame of reference), and for some reason the Standard Model prevents this.

The Higgs field has exactly the right quantum numbers to "balance" the different quantum numbers for the left-handed and right-handed fermions. If the Higgs field was zero everywhere, this wouldn't matter, but it gets a "vacuum expectation value," meaning that it is non-zero everywhere in the Universe, and so a left-handed quark moves along, bounces off the Higgs field and then becomes left-handed (and vice versa). The "excess" quantum numbers are sucked up by the background field - they are no longer perfectly preserved in the Universe. Think of it like the fermions are moving through mud; it slows them down, and since they're now moving slower than light, we say that they have mass. The mechanism that this all goes by is called "electroweak symmetry breaking," and requires that we can find a Higgs particle (the excitation of the field, or something that looks like it in more complicated theories - say technicolor), along with giving mass to the W and Z gauge bosons, the force carriers of the forces under which the left and right-handed fields are different (technically, it's SU(2)_left x U(1)_hypercharge. The remaining massless boson is the photon, and is a mixture of SU(2)_left and hypercharge, and couples to the remaining preserved quantum number: electric charge).

I'm sure there will be absolutely no questions about any of that.

Sadly, I actually have to do work for the rest of the day (banging rocks together, as it happens). I'll be back this evening, I hope.

And schmod, Thanks!
posted by physicsmatt at 9:22 AM on April 25, 2011 [6 favorites]

So is the Higgs mass just mass caused by the "energy" of the excited Higgs Bosons accelerating/binding to the electrons, or is the mass created by some kind of energy holding the Bosons together, or do they have some intrinsic mass?
posted by delmoi at 9:37 AM on April 25, 2011

(last comment till after work, I swear. For reals)

delmoi, no, the Higgs mass is just due to the properties of the Higgs field. There's nothing to prevent a mass term, and so there is one (in fact it's necessary for the electroweak symmetry breaking to occur). However, because it's just there (and would be if there were no fermions to couple to, in principle), it can be anything at all. We know it has to lie in a certain range of masses, and we've excluded the low end already, but now the Tevatron and LHC are just slogging through the remaining parameter space till we find the damn thing. At ~2 TeV, unitarity breaks down (meaning probabilities in the theory add up to more than 1), so we have to find SOMETHING - though not necessarily the Standard Model Higgs - before then.
posted by physicsmatt at 9:49 AM on April 25, 2011

Ah, Metafilter. I love the way a joking Steely Dan reference turned into a derail on correct use of the term "Doctor". Thank you for today's plate of beans.
posted by Mcable at 10:11 AM on April 25, 2011 [1 favorite]

Also, and I might be way off base here, but what a 'higgs boson' is, is a pertubation in the 'higgs field'. From what I understand, normally this doesn't happen -- the Higgs field is just a field that exists everywhere and drags on certain particles like the W bosons.

They're basically hoping that if they pump enough energy into the collider, it'll plink the higgs field hard enough to start it vibrating. That vibration would be a higgs boson, which would immediately decay into something else, and then something else again.

It's not like there are all these higgs bosons flying around normally that we can't detect. They'd actually have to create one to be able to see it. What they're really trying to prove is the existence of the higgs field itself, not so much that particular particle.

But the implication is that at some point in the history of the universe there was a large amount of energy causing vibrations in the Higgs field which then "decayed" to create particles that have mass: the "Big Bang". Is that correct? If so, where does the Higgs field come from and where does it sit in the creation timescale compared to other fundamental parts of the universe?
posted by Jehan at 10:12 AM on April 25, 2011

Pastabagel: Give us a minute. We're not just banging rocks together here.

Actually, it's pretty close to exactly what we're doing.
posted by jimmythefish at 10:15 AM on April 25, 2011

I like to think they discovered completely and definitively how the universe works via the LHC, but realized that space holds a terrible power and that they should not reveal the terrible secret of space.
posted by mccarty.tim at 10:17 AM on April 25, 2011

But the implication is that at some point in the history of the universe there was a large amount of energy causing vibrations in the Higgs field which then "decayed" to create particles that have mass: the "Big Bang". Is that correct? If so, where does the Higgs field come from and where does it sit in the creation timescale compared to other fundamental parts of the universe?

The point of this whole project is to figure out whether all of these fields are different ways of looking at the same phenomenon -- at the Big Bang, theoretically, there was no higgs field or weak field or electromagnetic field -- it was all the same.
posted by empath at 10:27 AM on April 25, 2011

We're not just banging rocks together here.

Actually, it's pretty close to exactly what we're doing.

The teeny-tiniest rocks we could find, heh?

/also not much of an idea what you peeps are talking about
posted by ZeroAmbition at 10:30 AM on April 25, 2011

Just to add a stoner math conversion — if I've done it right, an eighth of weed should be 1.96298 × 10⁹ GeV.
posted by klangklangston at 10:59 AM on April 25, 2011

Google says different.
posted by empath at 11:09 AM on April 25, 2011

if I've done it right, an eighth of weed should be 1.96298 × 109 GeV

Unless it's Mexican trash-compactor schwag ditchweed. Then it's nothing close to that.
posted by hippybear at 11:16 AM on April 25, 2011

empath,

Is it sufficient to say that, if something is quantized, it's a particle?

I have trouble seeing how a limitation in group behavior spawns a particle. I have no trouble seeing how the math can look particulate, of course.
posted by effugas at 11:20 AM on April 25, 2011

Aww, man, I knew this sack was light.
posted by klangklangston at 11:34 AM on April 25, 2011

Is it sufficient to say that, if something is quantized, it's a particle?

Well, if it's quantized, it's not infinitely divisible, and so it has a particle-like nature. Although instead of existing as an excitation in a field like a fundamental particle, it exists as an excitation in other particles.
posted by empath at 11:39 AM on April 25, 2011

I can't help wondering what Pythagoras would have made of this particle stuff.
posted by stonepharisee at 12:09 PM on April 25, 2011

I'm pretty sure he would have been right at home, because fundamentally the universe seems to be exactly what he thought -- nothing but math and geometry.
posted by empath at 12:13 PM on April 25, 2011

Google says different.

Only off by 13 orders of magnitude.

Pretty close, if you're stoned.
posted by eriko at 1:59 PM on April 25, 2011

I love all of you right now. Even if they didn't find the Higgs Boson yet, this is a truly awesome conversation.
posted by Kevin Street at 2:05 PM on April 25, 2011 [1 favorite]

I have trouble seeing how a limitation in group behavior spawns a particle. I have no trouble seeing how the math can look particulate, of course.

Well, a proton is really no more of a "particle" than a phonon is, if by "particle" we mean something like a billiard ball which is what most people's mental model of a particle is. The universe doesn't contain any particles in the absence of intelligences requiring abstractions.
posted by atrazine at 2:05 PM on April 25, 2011

Only off by 13 orders of magnitude.

Pretty close, if you're stoned.

That's what I told my dealer when I paid him in femto-dollars.
posted by atrazine at 2:07 PM on April 25, 2011 [1 favorite]

I asked a colleague (who happens to be on the ATLAS team) if getting excited about the purported results from this leak was worth my time. His comment: "Not even a little bit. The results out of CERN [of the detection of something weird] are worth thinking about a bit, but the 'detection' reported here is almost certainly nothing."
posted by Betelgeuse at 2:28 PM on April 25, 2011

I don't know what any of this means. I am enjoying it thoroughly.
posted by lazaruslong at 2:32 PM on April 25, 2011 [2 favorites]

I don't know whether Dr. Wu is a Professor

Somewhere upthread someone linked to her CV, and she's a professor. As far as I know, the title "Professor" is preferred in any discipline for someone appointed at any sort of professorial rank, no different in physics. Term professors, adjunct professors, tenured associate and full professors, untenured assistant professors, without respect to the terminal degree -- but I do believe these things work a little differently in Europe.
posted by fourcheesemac at 4:48 PM on April 25, 2011

♫ [D11]Are you [Gmaj7]with me Doctor Wu?
Are you [Bbmaj7]really just a shadow of the man [Ebmaj7]that I once knew?[Gm7]
She is [Cm7]lovely, yes, she's sly, [F11]and you're an [Gmaj7]ordinary guy [Bm7]
Has she fi[Cmaj7]nally got to you? [Gmaj7]Can you [C/F]hear me, Doctor? [D/E]
posted by ovvl at 5:07 PM on April 25, 2011

one thing to remember is that the Higgs boson isn't the source of all the mass in the Universe. It isn't even the source of 0.1% of the mass in your body

I hear it can knock out 52 bulls though.
posted by Smedleyman at 6:02 PM on April 25, 2011

Back. Hmm, looks like one thing that wasn't addressed (other than unit conversions for the world's least efficient drug dealer) is Jehan's question about the Higgs in the early Universe.

So whenever anyone says "there was a lot of energy around," your first question should be "in what form?" Energy, despite what Hollywood tells us, isn't a glowing blue fluid that floats around and gives people superpowers. It has to take the form of mass, kinetic energy, or potential energy (which is to say, stored in some field). The Universe had a very high energy density early on, but it was in the form of thermal energy, so just random kinetic motion of particles. Which particles? Well, every particle that was light enough so that, whenever two other particles came together in a collision, there was enough kinetic energy to convert to the rest energy of some new particle. So, for a temperature T (which we can measure in the units of energy, GeV), every particle with mass less than or approximately equal to T was floating around, smacking into each other.

For very early times, T was high enough that the Higgs was in this mix. But it wasn't the only thing, or even the most important thing around. Top quarks (175 GeV), W bosons (80 GeV), Z bosons (91 GeV), and every other particle we know of were there too, along with some we don't know about yet (dark matter, anyone?). As T dropped, due to the expansion of the Universe, particles that were heavier than T could annihilate into new light states, but couldn't get created in collisions of other particles in the thermal bath. So, gradually, the heavy states froze out, though you can get some relics left over since the last few particles couldn't find antiparticles to annihilate against. This is how we end up with dark matter in many scenarios. The Higgs would just decay away though.

So the point of that is that the Higgs was in the early Universe, but wasn't especially important. Now, the mechanism of electroweak symmetry breaking MAY have something to do with the reason we have matter today, and not equal matter and antimatter (which would be a Bad Thing, since there wouldn't be enough stuff around to build a star out of). When electroweak symmetry breaking happened, it caused a phase transition in the Universe. But it couldn't happen everywhere at once, so you end up with a bubble of the new "broken" symmetry expanding into the Universe where the symmetry was unbroken. Think of it like a bubble of gas nucleating in boiling water. It turns out, that under certain circumstances, this bubble can distinguish between matter and antimatter (technically, it breaks charge-parity - CP - symmetry), which is a necessary but not sufficient step to create matter over antimatter. Currently, it doesn't seem that this what actually happened, but that research might change as we better understand the physics at a few hundred GeV.

Finally, it is postulated that, VERY early in the Universe (basically the -ang part of Big Bang), a field called the inflaton caused the Universe to expand exponentially - the period of inflation. This field would leave the Universe very very very empty and very very very cold. Then the field would dump all it's energy into the vacuum, reheating the Universe in the process, leading to the whole thermal bath thing I described above. This is somewhat speculative though; it explains a lot of observations about the Universe, but it difficult to imagine how to test.
posted by physicsmatt at 6:52 PM on April 25, 2011 [6 favorites]

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