EPTParticle Physics: Higgs Hunt etc. - Page 3
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rubio91
Italy111 Posts
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BGrael
Germany229 Posts
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arbitrageur
Australia1202 Posts
Q: Why is LHC taking so long. What's the constraint(s) that stop(s) it from figuring out if it exists in a shorter time scale? | ||
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Notfragile
Greece713 Posts
The OP tries to cross the line where a scientific explanation is accessible for the "masses" and goes into a more "you have to have some solid physics/chemistry understanding, in order to read that" approach. Criticism + Show Spoiler + Keeping that in mind, I have to also agree with precious posters (and Toaster) who said that the analogies and the jokes were... kinda out of place. Theese jokes will not make someone who does not have any interest in particle physics read an article on that subject. (BTW i liked the irony of the TL;DR) Praise + Show Spoiler + Now, for a person who has studied science this article can be VERY insightful. It bridges the gap between a hard scientific paper (whoose target audience is scientists of the same field) and of standard popularised articles (whoose target audience is someone without any knowledge of the field at all). For me (undergrad in chemistry, have studied quite a bit of quantum mechanics) it just hit the sweeeeeeeeet spot. It really provided information about the situation (with some explanation behind it), while not demanding extreme knowledge about the subject. The OP put a great effort in writing this thing, that only a few of TLers will care to read. Yet, those of us who DO care, owe a huge thanks to Cascade for it. Perhaps some awesome TLers with a degree in a science can do the same thing. Create a post about a subject of their field and try to explain it to fellow scientists of other fields (or other people who really want to learn something) in a non oversimplified fashion. It would be nice if we managed to create a movement of knowledge spreading. (So we would love to see more of some Cascade posting) | ||
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Cascade
Australia5405 Posts
On October 13 2011 20:12 arbitrageur wrote: Fantasmic article Q: Why is LHC taking so long. What's the constraint(s) that stop(s) it from figuring out if it exists in a shorter time scale? A: It is because of the protons the collide being a mess to disentangle. Actually you can get a hint if you read the part about the strong force in the .pdf i edited in just now. Briefly, it is due to the proton-proton collisions creating A LOT of events that look very much like an event with a higgs. So there is a huge background to the signal in most cases. They record billions and billions of events, and only a few of them actually contains Higgs (if it exists). It is crazy hard to determine, among the billions of events, if some of them actully are Higgs events or not. An analogy would be looking for a nail in a haystack, where some of the straws look damn similar to nails. | ||
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Bill Murray
United States9292 Posts
what would you pick, personally? edit: where would you invest time into next in an area that still looks optimistic? | ||
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leo23
United States3075 Posts
the higgs particle allows the gauge symmetry to exist? if the higgs particle doesn't exist does that mean that the crazy high accuracy for the experiments mentioned are not really accurate? im also curious about your educational background! | ||
Plexa
Aotearoa39261 Posts
On October 13 2011 14:37 Skarjak wrote: Don't worry, he didn't actually explain anything, so it's perfectly normal that you didn't learn anything. The reason the Higgs is necessary is that the particles we observe have different masses. Other than the Higgs, there is nothing that would explain why particles containing the same number of quarks would have different masses, or why they even have mass at all. The Higgs give them their masses, and it is the last particle predicted by the standard model of particle physics to have not been detected yet, mainly because it requires very energetic collisions to produce these. That's why the LHC was necessary. The standard model is what we use in microscopic physics. It allows for the existence of many particles and has been, generally, a huge success. If somehow, the Higgs does not exist, then there is something fundamentally wrong with the standard model. That would be a major revelation for all physicists and would likely lead us to make huge progress. In fact, finding the Higgs might almost be a bad thing, since it might very well confirm the standard model without teaching us anything. I am personally hoping we don't find it. This is exactly what several physics profs have told me as well. They all hope that we dont find it so partical physics profs still have a research job lol | ||
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evaunit01
United States512 Posts
One principle to rule them both, one principle to find them. One principle to write them both, and in the Lagrangian bind them This made me lol! | ||
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rubio91
Italy111 Posts
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HallBregg
134 Posts
a)You need to specify the particle conted on the theory as well as the gauge symmetries to define the theory!! b)There are plenty of higgless electroweak symmetry breaking sector theories which left the rest of the standard model unchanged, for example Technicolor theories have become quite popular lately. c)The plot you show assumes a model for the higgs sector, which is used to determine the the product particles you look for as a higgs products, however its entirely possible a theory with a light higgs which would led to different decay products to the ones that are being looked for. | ||
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CloudCat
Singapore158 Posts
 Much better than confusing lecturers. Though I feel that a more "known" topic like an introduction to quantum physics would have been a better start than this one. Or E=mc^2, seeing that everyone knew the equation way before they knew what it was for, if they ever found out. | ||
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Cascade
Australia5405 Posts
On October 13 2011 20:56 leo23 wrote: the higgs particle allows the gauge symmetry to exist? if the higgs particle doesn't exist does that mean that the crazy high accuracy for the experiments mentioned are not really accurate? yes on the first. the Higgs stops the symmetry from being broken. for the accurate descriptions: the equations doing the calculations will hopefully be the same. However, we may have to rethink where the equations come from. On October 13 2011 21:17 rubio91 wrote: I don't see all this need of the Higgs Boson not existing (and i actually think it exists). Even if we find it there are still so many things to explain/discover etc... just look at the whole Neutrino thing, and it is not the only discovery in recent physics. Finding the Higgs just mean that the SM (standard model) works good, but does not mean it will end our Physics research Well, most scientist (at least in my community) believe that the neutrino OPERA measurement is some experimental error. While there are some subtle flaws in the mathematics of the standard model, it would not be easy to use them to motivate another even more expensive accelerator from politicians. So if we find a standard model Higgs and nothing else, itll be tougher to get funding. On October 13 2011 21:34 HallBregg wrote: Nice article, nonetheless let me point out: a)You need to specify the particle conted on the theory as well as the gauge symmetries to define the theory!! b)There are plenty of higgless electroweak symmetry breaking sector theories which left the rest of the standard model unchanged, for example Technicolor theories have become quite popular lately. c)The plot you show assumes a model for the higgs sector, which is used to determine the the product particles you look for as a higgs products, however its entirely possible a theory with a light higgs which would led to different decay products to the ones that are being looked for. a) what i tried to say is with the matter particles decided (given fermionic sector) and fixed gauge groups, the force carriers (bosonic sector) comes out from gauge symmetry. except the W and Z mass. Ill have a look at what i wrote and see if i need to clarify. b) Yes, there are plenty of BSM models that can take care of that. Plenty of BSM that can take care of any scenario i feel? Probably is a set of SUSY parameters that would explain elefants suddenly jumping out of the collisions. My point is: if we dont see any higgs, and nothing else either at LHC, it is hard to tell which one of the BSMs to go for. Im not a BSM expert though, so feel free to tell us a bit more.c) yes, im talking about the SM higgs, ill add that to the OP, thanks. Im trying to cover the BSM possibilities in the "no higgs" section. Anyways, i feel that this last discussion is a bit over the heads of most in this forum, i'd like to keep it understandable without a master in particle physics. | ||
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Cascade
Australia5405 Posts
On October 13 2011 21:46 CloudCat wrote: Really enjoyed reading this. Much better than confusing lecturers. Though I feel that a more "known" topic like an introduction to quantum physics would have been a better start than this one. Or E=mc^2, seeing that everyone knew the equation way before they knew what it was for, if they ever found out. have a look at the .pdf at the top of the OP. it goes through the history of quantum mechanics to some extent. | ||
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Cruncharoo
United States136 Posts
On October 13 2011 10:21 JeeJee wrote: All I got from this is that we're looking for the higgs boson because we're expecting it in our magical equation for the world, and we expect to have the results within a year. Can that get any more vague? I'm not a physicist by any means, actually a math major, but here's what I think he was saying. Physics has a model ("magical equation") that can predict with a very high accuracy experimental results. However, for this model to work the equations must account for there being a HB which up until this point we have not been able to observe. Because of how accurate the model predicts results we trust the model and are now looking for the HB. As far as I know this happens a lot in Physics (and probably other fields as well), a lot of Einsteins equations pertaining to relativity were able to accurately predict things that were not yet observable with scientific tools of the time. | ||
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Tuczniak
1561 Posts
I didn't get starcraft jokes, but dawg was great. | ||
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TheToaster
United States280 Posts
On October 13 2011 18:35 SgtCoDFish wrote: Can you at least verify if the statement that we'll "know in a year" if the Higgs exists or not is true? Are there any sites/articles you can recommend to us to find out more on the topic? Just with all scientific matters it's really not a question of "when" a development will emerge, but "if" they will emerge. Even if the Higgs particle supports and coincides with the entire Standard Model, it still exists only in theory. But purely based on LHCs progress, predictions are still hard to make. The LHC was inaugurated in 2008, but it only recently started to run unreplicated experiments around about a year ago. And advancements already claimed to have been "made" on the Higgs particle are still based on statistical speculation, such as its mass-energy composition. So basically the answer is "Who really knows?" Regarding sites that yield good info on the LHC, I would actually recommend CERNs homepage for the laboratory itself: http://public.web.cern.ch/public/en/lhc/LHC-en.html The site does a good job of explaining the technology equipped at different collider experiments without going into mind-numbing detail. Like the original post said, the events happen so fast that not even thousands upon thousands of individual sensors can capture the entire sequence in its entirety. In addition to that, the amount of digitized information collectible from each event can confuse even the worlds fastest supercomputers (which is why researchers filter out the "unnecessary" data). The sights info serves to shows how fragile and complex testing really becomes when you deal with such massive energy concentrations. Other than that, generally stay away from articles written by mass media such as the New York Times: their focus lies on gaining readers within the general population, which can oversimplify a huge amount of material and turn decades of dedicated research into flashy bullshit similar to what's found in this thread. But I do have to somewhat apologize for the amount of denouncing I did in my last post. You can't expect perfectly formal and proper scientific thought from a site dedicated to gaming. After all, such content has to be placed under a "general" tab due to its irrelevance to pro gaming itself. | ||
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Cascade
Australia5405 Posts
On October 14 2011 09:43 TheToaster wrote: So basically the answer is "Who really knows?" (sorry for pulling a quote out of context.) Ofc, we will never be 100% sure of anything ("I think, therefore I exist. I guess."), but if the LHC continues to take statistics as it is doing currently, it will find the standard model Higgs if there is one, by the end of next year. With at least 5 sigma significance, which is like 99.99% probability or something. I realise that this is amounting to "do not!" "do to!", so here are the slides from the ATLAS presentation on a conference in japan 2 weeks ago that I attended: EDIT (link removed): on second though I want to check with some ATLAS friend before giving you the link, brb soon, sorry. EDIT2 (link repalces): ok got green light. they are public. hf. https://indico.cern.ch/materialDisplay.py?contribId=72&sessionId=14&materialId=slides&confId=149305 (I think the slides are public, dont remember if i needed a password for them... well if they dont open for you, I guess they are confidential until the proceedings are out, and i shouldnt be giving them to you anyways.  Ill find some older talk at that point.)feel free to look through all slides, but specially at page 14 which is the same plot as in the OP, but with the lower imit 146GeV, and page 15, where it says at the bottom that a standard model higgs will be found by the end of 2012. If it is not found by then (all the mass range will be exluded) that is a sign that we need more than just the standard model. "BSM" Beyond Standard Model. Exactly what BSM model, we do not know (unless we see some BSM signal next year), but I'm sure a lot of people will be happy to try to find out. You are absolutelety correct that this a crazy difficult measurement, but they have a lot of people working on it, and this is also the reason there are TWO independent detectors (ATLAS and CMS) both looking for Higgs. The corresponding plot from CMS looks very similar, which is a sign that things are in order. It is tricky, but these guys are really smart and really know what they are doing. It is not like Dustin Browder trying to create a balanced game. Feel free to look through the slides to get a feel for how they approach it, and I'll be happy to answer questions if things are unclear. I'm not an experimentalist, but I think i can explain most of their methods at least at a basic level. | ||
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only.her0
Singapore78 Posts
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radiatoren
Denmark1907 Posts
Tomorrow the European Organization for Nuclear Research, more commonly known as CERN, will reveal something about the Higgs boson. Back-to-back public seminars are scheduled for 2 p.m. Zurich time (8 a.m. Eastern) on Wednesday, Dec. 13, each from one of the main ongoing experiments at the Large Hadron Collider (LHC), CERN’s colossal, headline-grabbing atom smasher. And yes, Big Bang Theory fans, you can watch them live. Also known as the so-called “God particle,” the Higgs boson is one of the most important particles in physics, since it’s responsible for creating mass itself. There’s just one problem: It might not exist. Although science said it should, so far no experiment has shown any sign of the elusive particle. The science world has been buzzing with rumors about the Higgs boson in the past few weeks after details about tomorrow’s agenda leaked out. From what various physics sites have published, the seminars are expected to reveal strong signs of the Higgs boson particle, but not with enough certainty to call it a bona fide discovery. That makes sense, since the LHC wasn’t expected to catch sight of the Higgs since it still hasn’t powered up to its full capacity yet (it’s running at about half energy). CERN Director General Rolf-Dieter Heuer told Canada’s National Post he expected the final word on the existence of the Higgs to come by October 2013. You can watch the lecture live from CERN’s webcast here. Once the announcement is public, you can discuss it with other physics enthusiasts at CERN’s Facebook page. The blog Quantum Diaries is hosting a liveblog of the even. And, of course, you can read the news on Mashable. source it was released yesterday. There is about 1 hour till the public seminar! Watch it live here! | ||
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