Sciencemadness Discussion Board

Higgs Boson Seen?

DerAlte - 3-7-2012 at 06:03

Physicists find new particle, but is it the Higgs?

http://www.nature.com/news/physicists-find-new-particle-but-...

The famous ‘god particle’: let there be mass, and there was mass.

Der Alte


[Edited on 3-7-2012 by DerAlte]

hissingnoise - 3-7-2012 at 06:46

It's just another goddam particle . . .

nezza - 4-7-2012 at 01:56

I can'r remember where I read this but I found it pretty funny :-


The Hunting Of The Quark


"Just the place for a quark," the Gell-Mann cried,
As he landed his crewmen at Cern,
"An underground tunnel with protons inside, Let's crash them and see what we learn.

"Just the place for a Quark! I have said
it twice:
Come on, there is plenty to do.
Just the place for a Quark! I have said
it thrice:
Let's see if Higgs boson is true."

The crew was complete: it included a chap
Who'd met a Higgs boson in Spain,
Or he may have just dreamt it while having
a nap,
But he'd know if he saw one again.

The Gell-Mann addressed them when all
were aboard:
"I'm going to turn on the switch,
So keep your eyes peeled, lads, we need
to record,
Events that could make us all rich.

"Remember that what we're hunting is
a quark
That's known as the boson of Higgs,
It makes a dull noise like a sea lion's bark, Its tail is quite bent like a pig's."

But one young crew member looked
quite unconvinced.
And asked, "Are you really quite sure, That if it goes wrong we won't find
ourselves minced,
And spat out in bits on the floor?"

"Is that," said the Gell-Mann, contempt in
his voice,
"What lecturers teach you in college? Forget health and safety, take risks
and rejoice,
At pushing the boundaries of knowledge!"

They set off to find the one missing quark,
That might prove their theories correct.
That boson elusive that hid in the dark,
To gain everybody's respect.

They sought it with thimbles, they sought it
with care;
They pursued it by day and by night; "We'll ne'er catch the blighter," they said
with despair;
It almost moves faster than light."

But just as the project was nearing its goal, And the mood was pure rapturous glee,
The universe fell down a gaping black hole, For the quark was a boson, you see.

hissingnoise - 4-7-2012 at 03:33

Well, they're saying they've found it?

watson.fawkes - 4-7-2012 at 07:57

Quote: Originally posted by hissingnoise  
Well, they're saying they've found it?
Well they're saying that they've found something. Here's the CERN press release. They've got a boson and its mass is about 125 - 126 GeV. That's all that's in the press release. More detail, but not more particle properties, in the releases from ATLAS and CMS.

In particular, they don't yet know its charge or spin. It's certainly possible that they've found something new, not the Higgs, that has as-yet no theory for it. Time, meaning more data, will tell.

ScienceSquirrel - 4-7-2012 at 08:02

They have not really found it.
They look at the bits of crap left after it has exploded and think they might have had it.

DerAlte - 4-7-2012 at 09:10

Essentially, CERN found evidence of what used to be called a ‘resonance’ at c. 125Gev. A resonance is an indication of a particle of high energy and extremely short lifetime. It seems to fit the profile established for the Higg’s, but time will tell. If confirmed, it will provide experimental backing for the Standard Model, which has been tentatively endorsed by most physicists for several decades.

As Watson.Fawkes points out, only the mass is confirmed. The Higgs is expected to interact with all those particles having mass, i.e. all except photons and gluons (even the e-neutrino). Further properties must be shown experimentally before full confidence that this is Higgs can be entertained. Notice particularly that the Standard Model does not fix the mass.

If confirmed, the next step to Supersymmetry requires energy of such a magnitude that CERN and other machines are many orders too low; the final horizon is beyond man’s energy ability, except for theory.

These are the properties of the conjectured Higgs Boson, excerpted from Wiki’s article on Higg’s Boson; (it may either help or confuse!):

The Standard Model completely fixes the properties of the Higgs boson, except for its mass. It is expected to have no spin and no electric or color charge, and it interacts with other particles through the weak interaction and Yukawa-type interactions between the various fermions and the Higgs field…

Mathematical consistency of the Standard Model requires that any mechanism capable of generating the masses of elementary particles become visible at energies above 1.4 TeV;[4] therefore, the LHC (designed to collide two 7 to 8 TeV proton beams) was built to answer the question of whether or not the Higgs boson actually exists.[5]…

In the Standard Model, the Higgs field consists of two neutral and two charged component fields. Both of the charged components and one of the neutral fields are Goldstone bosons, which act as the longitudinal third-polarization components of the massive W+, W–, and Z bosons.[citation needed] The quantum of the remaining neutral component corresponds to (and is theoretically realized as) the massive Higgs boson. Since the Higgs field is a scalar field, the Higgs boson has no spin. The Higgs boson is also its own antiparticle and is CP-even, and has zero electric and color charge.[citation needed]…

The Standard Model does not predict the mass of the Higgs boson.[citation needed] If that mass is between 115 and 180 GeV/c2, then the Standard Model can be valid at energy scales all the way up to the Planck scale (1016 TeV).[citation needed] Many theorists expect new physics beyond the Standard Model to emerge at the TeV-scale, based on unsatisfactory properties of the Standard Model.[citation needed] The highest possible mass scale allowed for the Higgs boson (or some other electroweak symmetry breaking mechanism) is 1.4 TeV; beyond this point, the Standard Model becomes inconsistent without such a mechanism, because unitarity is violated in certain scattering processes.[citation needed]…

As of July 2011, the precision electroweak measurements tell us that the mass of the Higgs boson is lower than about 161 GeV/c2 at 95% confidence level (CL). This upper bound increases to 185 GeV/c2 when including the LEP-2 direct search lower bound of 114.4 GeV/c2.[31] These indirect constraints rely on the assumption that the Standard Model is correct. It may still be possible to discover a Higgs boson above 185 GeV/c2 if it is accompanied by other particles beyond those predicted by the Standard Model.[citation needed]…

On 2 July 2012, the ATLAS collaboration published additional analyses of their 2011 data, excluding boson mass ranges of 111.4 GeV to 116.6 GeV, 119.4 GeV to 122.1 GeV, and 129.2 GeV to 541 GeV. They observed an excess of events corresponding to the Higgs boson mass hypotheses around 126 GeV with a local significance of 2.9 sigma.[59] On the same date, the DØ and CDF Collaborations announced further analysis that increased their confidence. The significance of the excesses at energies between 115-140 GeV is now quantified as 2.9 standard deviations, corresponding to a 1 in 550 probability of being due to a statistical fluctuation. However, this still fell short of the 5 sigma confidence, therefore the results of the LHC experiments are necessary to establish a discovery. They exclude Higgs mass ranges at 100–103 and 147–180 GeV.[60][61]

Der Alte

Endimion17 - 4-7-2012 at 09:44

^^not only the mass, but the lifetime and decay products (two photons).

It's probably Higgs boson.

Few months ago Tevatron's data indicated there is such particle. Tevatron is offline, but the data is still being analyzed.

watson.fawkes - 4-7-2012 at 11:14

Quote: Originally posted by Endimion17  
^^not only the mass, but the lifetime and decay products (two photons).

It's probably Higgs boson.

Few months ago Tevatron's data indicated there is such particle. Tevatron is offline, but the data is still being analyzed.
Saying that it's probably the Higgs boson really means "the only thing we have even a partial understanding of that fits the observation is the Higgs boson". I don't mean to be pedantic about this. If you read the reports from the detector groups, they are far more careful about their claims. It boils down to "it's the Higgs or something brand new". There are reasons to believe it's the Higgs, but they aren't definitive. It's basically impossible to quantify the difference in belief / probability between the partially-known and the completely unknown. So I'd make such a statement this way: "If it's something we already have theory for, it's almost certainly the Higgs." That, however, is a big caveat there.

The CMS link I posted has some decent reading about decays. They looked at five decay channels. Only one of them was the γγ (gamma-gamma) channel; that's two high-energy photons. The other channel they got good resolution from was the ZZ one. That's two Z0 neutral weak-force gauge bosons. Since those immediately decay, the signature looks like a quartet of four electrons or a pair each of electrons and muons.

It's important to understand just how these groups analyze the data. The data sets they deal with are so large that it's no longer feasible to fully analyze each event to completeness. Instead, what they do is to filter their events by decay signatures, and there's only a handful of signatures they look for. If they find a likely signature, they examine it more closely. In other words, there's an observational bias based on the theoretical construct they're searching for. This doesn't invalidate the mass resonance they've found, mind you. What it does say is that it provides no evidence for the absence of other decay channels. That will take a lot more data analysis. In particular, the current analysis for channels would not distinguish a Higgs and a particle that used all the decay channels of the Higgs and then some.

I didn't see any results about decay lifetime. I wouldn't expect it yet, either. Neither does the CMS group: "more data are required to measure its properties such as decay rates in the various channels (γγ, ZZ, WW, bb and ττ) and ultimately its spin and parity"

The Tevatron group released their preliminary analysis a couple of days ago.
Quote: Originally posted by DerAlte  
Essentially, CERN found evidence of what used to be called a ‘resonance’ at c. 125Gev.
Resonance is still the term of art. It just doesn't tend to be found in popular media coverage.

Rogeryermaw - 4-7-2012 at 12:00

what i took away from the article is that an interminable mountain of data would have to be analyzed before any conclusion could be drawn meaning: "we have no idea what we have made. we made something. it's cool. no idea what it is. were looking into it. news at 11."

Paddywhacker - 5-7-2012 at 17:18

Its been found?

Not interested. I didn't lose it, so it must be somebody else's. Maybe somebody is Switzerland lost it while they were blowing a flugelhorn.

Endimion17 - 6-7-2012 at 03:15

I know the basics of their work, such as sifting through the data with some theoretical bias. They have to start from something, and the computers are simply not fast enough to do all that in a reasonable amount of time.

I doubt there'd be such commotion and cavorting and press release if they thought the discovery is not important. CERN is a serious institution. The thing they've found is a boson, and so far it seems to be a Higgs boson, according to the currently crunched data. It's not like they did the experiment few days ago. This is a result of months and months of work. Yes, the data still needs to be checked and rechecked, but it's not like they pulled this thing out of their asses.
Higgs must've known about it; the reason he got emotional at the press release was because it's a huge thing being presented to the public. Who wouldn't be? The guy is still alive and if this really turns out to be his boson, I hope he'll receive a Nobel prize.

Question - has anyone of you contributed to CERN by giving its free CPU time via BOINC? I did for a short time, but after I've bought the laptop, I decided to retreat from the project because I didn't want another thin plastic furnace in my room. The desktop computer at home is too weak to support XP, today's media requirements and Internet browsers together with such endeavours.

phlogiston - 6-7-2012 at 04:37

Me too, for a short while, but I also didn't want to fry my laptop.

I greatly enjoyed a visit to CERN about a year ago while i was at a nearby conference. If you ever happen to be nearby, I can greatly recommend it especially if can get a tour where they get an engineer to show you around in the magnet production facility etc. An unbelievable project and fascinating science.

watson.fawkes - 6-7-2012 at 05:51

Quote: Originally posted by Endimion17  
I doubt there'd be such commotion and cavorting and press release if they thought the discovery is not important.
[...]
It's not like they did the experiment few days ago. This is a result of months and months of work.
It's an important result whether the boson is the Higgs or not. Both would be very significant discoveries, but with completely different consequences.

As I understand it, the data that generated this result was all from the 8 TeV run they're calling the 2012 data. The previous run was in 2011 with a 7 TeV beam. So not exactly yesterday, but it's very recent, and only a few months of running the machine. I can hardly be surprised that all they've got so far is the mass. They've got an order of magnitude more data to collect over the next few years. Lots more in there that they'll be able to observe.

franklyn - 7-7-2012 at 21:33

Somebody really saw Higgs Boson ?

Did they get an autograph ?

What was he wearing ?

___________________________


Somebody once said that if you want to know how pocket watches work
the worst method you could employ would be to fire them at each other
to observe the pieces that fly out of the collision. That says something
about their experimental methodology. I don't pretend to understand it
and that's just as well since the proponents of these schemes don't
actually understand the results themselves. That's also saying something
about their experimental methodology. This has to be the next best scam
after global warming data gathering.

.

watson.fawkes - 8-7-2012 at 05:43

Quote: Originally posted by franklyn  
I don't pretend to understand it and that's just as well since the proponents of these schemes don't actually understand the results themselves.
"I don't understand it, therefore they can't possibly understand it." If you insist.

I have an amendment from a previous statement I made, based on some news.
Quote: Originally posted by watson.fawkes  
So I'd make such a statement this way: "If it's something we already have theory for, it's almost certainly the Higgs." That, however, is a big caveat there.
I'm amending the phrase "almost certainly". The news is that the decay channels don't seem to have the expected relative rates that they expected. There's evidently an excess in the γγ channel. On the other hand, there are also alternate Higgs field theories. In particular, there's a supersymmetry version with five Higgs bosons. Supersymmetry, though, still has no experimental evidence, though there is at least a theory for it. So my amendment is to change "almost certainly" to "probably".

DerAlte - 8-7-2012 at 09:06

We note that the omniscient WF informs us that there is a slight problem in Geneva. Reference, WF, or are we to take it on trust from you like AGW?

On a lighter side, http://cosmiclog.msnbc.msn.com/_news/2012/07/05/12585302-lig...

Although WF is almost totally without humor, I have no doubt he is encyclopedic about beers too. Actually I am not a fan of wheat beers, so WH will not doubt state that I am not a believer in beers either, to add to my major fault of not believing in science as not being a religious devotee of AGW.

Der Alte


[Edited on 8-7-2012 by DerAlte]

Poppy - 8-7-2012 at 09:09

I hate how the particle is simply called Higgs as no other particles stands for the name of a certain guy.
Its also ridiculous as it doesn't probably account for dark matter and dark energy problems, its just a quantum theory digging for expected pike results from high energy colliisions data. More of a profane prescription for dummies, yet to be confirmed.
How is it that still undiscovered things are believedly and unnavoidably belonging to god's deep secrets?

Damn

watson.fawkes - 8-7-2012 at 09:16

Quote: Originally posted by DerAlte  
Reference, WH, or are we to take it on trust from you like AGW?
[...]
I have no doubt he is encyclopedic about beers too.
The source is listening to Sean Carroll from CalTech on Science Friday last week, 2012 July 6. Go listen yourself.

I know nothing about beer. I have the good sense to remain silent about things I know nothing about.

Poppy - 8-7-2012 at 12:34

Quote: Originally posted by Poppy  
I hate how the particle is simply called Higgs as no other particles stands for the name of a certain guy.
Its also ridiculous as it doesn't probably account for dark matter and dark energy problems, its just a quantum theory digging for expected pike results from high energy colliisions data. More of a profane prescription for dummies, yet to be confirmed.
How is it that still undiscovered things are believedly and unnavoidably belonging to god's deep secrets?

Damn


anyway, Peter Higgs was so emotivated there. Apparently he was the only one of the six present in there.
Its the tribute of his life coming true in a matter of 2 years from a project that took 20 to be complete.

DerAlte - 8-7-2012 at 14:45

@WF
Thanks for the reference, it made interesting listening. But I did not hear any reference to a part your statement in the audio: "The news is that the decay channels don't seem to have the expected relative rates that they expected. There's evidently an excess in the γγ channel"

I don't know exactly what that would mean. I did get the impression that the decay mode was dual photon. The rest was there.

On the same page the graph under "What Higgs Boson Evidence Looks Like" certainly shows clearly that a particle was indeed detected. It's early days - we will have to see how this one evolves, but assuredly it will not be the fiasco that the recent tachyonic neutrino was!

Der Alte

watson.fawkes - 8-7-2012 at 19:16

Quote: Originally posted by DerAlte  
But I did not hear any reference to a part your statement in the audio: "The news is that the decay channels don't seem to have the expected relative rates that they expected. There's evidently an excess in the γγ channel"
It starts with a question of Ira's at 7:25. In the answer: "[...] there are hints [...] that it is not the simple vanilla standard model Higgs boson, that it is doing something a little bit different." At 8:27 "[...] we got twice as many events of two photons as you would have expected if it were just the vanilla standard model Higgs."

"Two photons" in this context means two gamma rays, because the energies involved are so high. Thus the moniker for the decay channel as γγ. The other major channel they detected the particle on was the ZZ channel (see above). Ira's guest Sean Carroll didn't mention it by name and hardly made reference to it at all.

DerAlte - 8-7-2012 at 20:20

@WF
Thanks for your patience in pointing out the exact locations in the video. And, had I paid more attention to your prior citations from CERN above, I would not have had to ask the question. But alas, we oldsters suffer from attention deficit along with failing memory.
Der Alte

DerAlte - 26-7-2012 at 08:59

So where do we stand with regard to the Higgs Boson, three weeks after CERN’s announcement? I did a Google search yesterday for follow up news, adding the filter ‘not God particle’ to exclude as much media rubbish and Higgsmania as possible. Nothing further from CERN; I would not expect it, the July 4 announcement was the result of several years hard work and for details one must await papers in the reputable Physics journals. Remember that CERN, with true scientific caution, did not announce their discovery until their confidence level reached 5σ. Neither did they claim that this was the Higgs Boson for certain, but a likely candidate: a short-lived particle had been detected as a decay product at 125Gev.

I found little. Higgsmania has subsided. A few naysays have emerged, e.g.

Higgs Boson May Be An Imposter, Say Particle Physicists
http://www.technologyreview.com/view/428428/higgs-boson-may-...
But this only suggests that other Higgs-like particles may be involved.

The only other reference I thought worth adding is the following, by a science writer, but well worth reading if you are interested:

Is it or isn't it? The Higgs boson story
http://www.gizmag.com/higgs-boson-cern-alternative-particle/...

Regards,
Der Alte

DerAlte - 13-8-2012 at 12:43

Hissingnoise's short comment, quote, "It's just another goddam particle . . ." seems to be a common reaction, and who's to say he's wrong? As Shakespear put it in Hamlet,
"There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy."

In this vein, the following is not really about the Higgs much but worth the read, IMO. That is, if you are interested in the general philosopy of science. Do not skip the comments either (it’s long):

http://blogs.scientificamerican.com/the-curious-wavefunction...

More or less, it’s about the dichotomy between the reductionists and those of the ‘emergence’ school.

Der Alte



DerAlte - 19-2-2013 at 10:17

Further Speculations on The Standard Model

http://cosmiclog.nbcnews.com/_news/2013/02/18/17006552-will-...
… Is the Universe in a metastable state?

Also see http://www.nbcnews.com/id/18416910/

Re Dark Matter and the ultimate fate of the universe, some suggesting a final state of matter domination rather then radiation dominated.

Or maybe only 3.7E9 years left until the end of time?
http://www.technologyreview.com/view/420963/time-likely-to-e...

The speculations of today’s physics are reminiscent of the speculations of the Gnostics in religion for the richness of their imagination …

Der Alte

hissingnoise - 19-2-2013 at 10:52

Yup, a whole lott'a guessin' goin' on . . .

DerAlte - 4-4-2013 at 12:11

Dark Matter

Not directly related to the Higg’s Boson, but one of comsmology’s major current concerns: dark matter. Some new results:
http://physics.aps.org/featured-article-pdf/10.1103/PhysRevL...
http://cosmiclog.nbcnews.com/_news/2013/04/03/17585037-space...
http://science.nbcnews.com/_news/2013/04/03/17587525-how-to-...

Der Alte

zed - 9-4-2013 at 17:47

Damned Higgs field. In the old days, you could go as fast as you wanted to, but nowadays we are restricted to the speed of light. Space just isn't the same product that it used to be.

watson.fawkes - 8-10-2013 at 06:12

Here's the press release from the official site for the Nobel Prize in Physics 2013 awarded to François Englert and Peter W. Higgs.

maxpayne - 9-10-2013 at 10:10

Man gets real Nobel prize for "discovering" hypothetical, unseen and unproven "particle", very funny.. Just another patching of endless theories so madness can go on and on..