Talk:Particle physics

From Wikipedia, the free encyclopedia

WikiProject Physics This article is within the scope of WikiProject Physics, which collaborates on articles related to physics.
B This article has been rated as B-Class on the assessment scale.
Top This article is on a subject of top importance within physics.

Help with this template This article has been rated but has no comments. If appropriate, please review the article and leave comments here to identify the strengths and weaknesses of the article and what work it will need.
Other languages WikiProject Echo has identified Particle physics as a foreign language featured article. You may be able to improve this article with information from the Slovenian language Wikipedia.
This article has been reviewed by the Version 1.0 Editorial Team.

Old talk (prior to April 2004) archived in Talk:Particle physics/archive 1.

Contents

[edit] Chart

Does wiki already have a chart like this [1]? I think it would make a nice addition to this (and other) articles.--Deglr6328 07:38, 18 Mar 2005 (UTC)

[edit] "Particle physics" or "Particle Physics"

Should this article be redirected from "Particle physics" to "Particle Physics"? Irpen 23:05, May 23, 2005 (UTC)

Please don't redirect. "Particle physics" is in line with Wikipedia's policies on capitalization of article names. -- CYD
I sure won't if you say so. I just asked. Irpen

[edit] Reductionism

Hi. I imagine there may have been some discussion of the "Particle physics and reductionism" section already, but I have to ask: what is it doing here? It's somebody's POV, and it's written using the "some people say..." type argumentation. The criticism it mentions is not really relevant to an article on particle physics (which after all has as its goal to reveal the fundamental laws of nature...). --RE 07:17, 25 September 2005 (UTC)

I'd never noticed it before, but it is a little but POV-y, and not very clear on what it's trying to say. If you rewrite/delete it, I certainly won't object. -- SCZenz 14:24, 25 September 2005 (UTC)
If you're looking for a reference on this subject, check out [2] and Anderson's "More is Different" article: Science, 177, 393-396. -- CYD
That is a good reference. The valid objection of RE to the section is that it is of the form "some people say" without saying who "some people" are, so-called weasel words, so if you want to keep the section's contents, perhaps you could edit it using those references to make it more concrete who says these things. --DannyWilde 03:42, 26 September 2005 (UTC)
OK, I'll edit it a bit with references. I'll also add something about defense of reductionism, e.g. by Steven Weinberg. --RE 04:03, 26 September 2005 (UTC)

==Is a proton a physics particle?== Scott 00:18, 30 September 2005 (UTC)

A proton is definitely a particle in physics. Do you mean something else by the question? --physicsdavid 00:22, 30 September 2005 (UTC)

Well yes Doctor Dave, Please see [3] Thank-You Scott 00:30, 30 September 2005 (UTC) I thought it was a good reference. Just my opinion, as it is a proton beam they have. Does that relate to particle physics? It's not like its a nuclear reactor Thanks, Scott 00:30, 30 September 2005 (UTC)

Ahhh... This is about the deletion of the Spallation Neutron Source..? That's a bit more complicated. An experiment done with particles need not be particle physics, and the line between nuclear physics and particle physics is notoriously hard to draw. (Even for funding agencies! The United States Department of Energy inexplicably counts neutrino experiments as nuclear, and requires them to be funded from a different source!) I think the SNS is probably more nuclear than particle, because it has no applications to investigating fundamental physics. -- SCZenz 00:36, 30 September 2005 (UTC)
By the way, the United States Department of Energy does fund neutrino physics, including at Fermilab --physicsdavid 01:33, 30 September 2005 (UTC)
Yes, yes. But it comes from their nuclear division, rather than their particle division, or something like that. Ask the people I work for, not me..!  :P -- SCZenz 01:40, 30 September 2005 (UTC)
Neutrino physics is funded through the DOE Office of Science in both their High Energy Physics (HEP) program and their Nuclear Physics (NP) program. (I work in the HEP part.) I think this just reinforces your earlier point that the line between nuclear and particle physics is "notoriously hard to draw." -- physicsdavid 17:21, 30 September 2005 (UTC)

Your word is good enough for me! You know that. I think you know who, is sleeping now. Really pisses me off, It's called staulking. Just so you know I'm out in the open, and referenced #40 Not that it will do any good..... Takes up too much unconstructive time from me. Anyway, getting late here. Isn't this the truth: [4] Catch up with you tomorrow! Caio Scott 00:47, 30 September 2005 (UTC)

Um, I didn't understand that last entry... Anyway. I removed the SNS link because it's more like nuclear physics what they're going to do there. It has more to do with the energies than with the type of particles, and there are nuclear physics experiments that have electron beams for example. At higher energy one looks at smaller things. SNS has lower energy and is designed to look at the nuclear forces (between nuclei/nucleons). But maybe there should be something about this in the article... --RE 01:01, 30 September 2005 (UTC)
The difference between particle and nuclear would probably be a good thing to add, yes. -- SCZenz 01:07, 30 September 2005 (UTC)

[edit] Removal of links to new physics theory

Sorry, in my comment for that removal I should have written see Wikipedia:Reliable sources. You might also look at Wikipedia:No original research. -- SCZenz 22:42, 23 December 2005 (UTC)

[edit] Links to website wrong?

when someone clicks on the "particle adventure" link it takes one to the credits page (????!!!!!!!) Hopefully someone could fix that 69.22.224.249 23:55, 28 December 2005 (UTC)

Done. Thanks for pointing it out. - mako 00:06, 29 December 2005 (UTC)

[edit] Alphabetical list of collaborations?

Should the list of collaborations be alphabetical? If so, Fermilab should be somewhere in the middle. Masud 20:16, 12 March 2006 (UTC)

On a related note--shouldn't the list of "collaborations" really use the word "laboratories" instead of "collaborations". e.g. CERN is a lab, LEP is a facility, and L3 is a collaboration/experiment. Josh Thompson 01:12, 19 November 2006 (UTC)

[edit] Do we have to use a STAR event display as first picture?

Heavy ion physics is not really particle physics proper i would say. Also, i am not really aware of any ground breaking scientific results from STAR, or even RHIC in particle physics. i propose to replace the image with a more famous event display, such as a classic bubble chamber picture like the discovery of Omega++ or neutral currents. A W from UA1 is also possible, or some LEP image. gbrandt 11:00, 3 April 2006 (UTC)

I think that a lot of this kind of discussion comes from the fact that people use "high-energy physics" and "particle physics" interchangeably. "High-energy physics" redirects to "Particle physics" on Wikipedia, for example. To use the example from this discussion, RHIC is undoubtedly a "high energy" machine even if it's arguable that it's a "particle physics" machine. It might not be LHC-scale, but it can collide (fully polarized) protons at a collision energy of half a TeV. Even Au ions, limited by their charge-to-mass ratios, can still be collided at 200GeV center-of-mass. To use another example: when running the heavy-ion program during pauses from the proton program, the LHC will introduce heavy-ion collisions at center-of-mass energies of several TeV.
I would go further, though, and support the idea that this kind of nuclear-collision physics can be considered as part of the diverse 'umbrella' of particle physics. Although it is funded by the (DoE) Office of Nuclear Physics, RHIC is definitely a lot more like conventional particle physics experiments than it is like conventional nuclear physics experiments. Sure, the collisions are a little messier than e+e- collisions - but so are hadron collisions (particularly in the future, at LHC energies), as we shouldn't forget that protons are themselves composite objects. Additionally, the aim of the field is not to investigate any property of actual nuclei; the nuclei involved are just tools employed in order to discover (done!) and determine the behavior (ongoing...) of the primordial matter and energy that pre-dated the existence of protons, let alone actual nuclei, in the Universe.
Finally, as regards the image itself, it is an excellent depiction of particle tracks in a solenoidal detector, albeit with rather more tracks than one would expect from an e+e- or pp collision (at current energies!) Please note, by the way, that I don't work on the STAR experiment. :)

C60 08:37, 16 May 2007 (UTC)

No, we don't have to. Feel free to change it if you can find another good picture. -- SCZenz 20:50, 3 April 2006 (UTC)
I found something but i have trouble with licensing. Does anyone have an idea of how to proceed correctly when putting research results (in this case event displays, but i can think of using illustrative plots) from DESY, CERN or other labs not in the U.S. into Wikipedia? With the US all research results seem to be PD, but what about Europe? gbrandt 10:46, 20 April 2006 (UTC)

[edit] 45 fermions?

Can someone explain how there are 45 fermions? I count 6 quarks, 3 leptons, 3 neutrinos. Plus antiparticles making at most 24.Jameskeates 09:47, 17 August 2006 (UTC)

Hmm - looks like 24 to me as well. See here:[5] --MichaelMaggs 10:19, 17 August 2006 (UTC)

Yeah I edited it. I thought I'd see if anyone objected but to be honest if they object they are wrongJameskeates 11:38, 17 August 2006 (UTC)

Particle counting is, at some level, a silly business. I can think how to get 48 (also count left- and right-handed separately) or 42 (but neglect right-handed neutrinos), but not 45. I can also get more than this by counting the quark colors separately, which gives 3*6 + 3 + 3 = 24. Then if I count handedness, but don't count antiparticles, I get 48... So now if I neglect the right-handed neutrinos, I get 45. Whoever did that count had taken a field theory course too recently, and is thinking in terms of theoretical fields rather than what anyone would actually refer to as distinct particles. Anyway, the right handed neutrinos are rather likely to exist, now that we know neutrinos are massive but very light, so I don't think excluding them is a good idea.
The point is, there isn't really a right way to count particles. Wikipedia should not be in the business of doing it. -- SCZenz 19:15, 17 August 2006 (UTC)


3 colours of 3 left handed up quarks, 3 colours of 3 left handed down quarks, 3 colours of 3 right handed up quarks, 3 colours of 3 right handed down quarks, left handed electron, right handed charged lepton, left handed neutrino = 15. Times 3 generations = 45. jay 21:38, 26 August 2006 (UTC)

As I said above... That's a count of the degrees of freedom in the Standard Model; for most purposes, however, it is not a sensible way to count particles. For example, left-handed and right-handed electrons turn into each other by interacting with the Higgs Field (or whatever spontaneous symmetry breaking mechanism that actually exists) so often, that us poor experimentalists tend to think of the "electron" as a single kind of particle. This counting method, as is clear from the confusion above, will be obscure to anyone with less than a year of graduate-level coursework specializing in particle physics. So I don't think Wikipedia should count particles this way. -- SCZenz 21:07, 7 September 2006 (UTC)
This is slightly more than semantics and actually has physical meaning. For instance if you consider the Universe at a high enough temperature, then the free energy contains a term -N_F \frac{7}{8} \frac{ \pi^2}{90} T^4 (NF is the number of fermions). This has important consequences for early universe cosmology. 15 fermions per generation is also an important number for grand unified theories because each of the 15 fermions are placed on equal footing. jay 17:50, 26 September 2006 (UTC)

[edit] Timeline of particle physics

I proposed to create the article "Timeline of particle physics", as Timeline of cosmology or Timeline of particle physics technology. Lseixas 23:39, 26 December 2006 (UTC)

I created the article and linked this article with "Particle physics". Lseixas 00:06, 31 December 2006 (UTC)

[edit] Template of Particle physics

I proposed to create the "template:particle_physics". See the prototype Template:Particle physics.

[edit] Publications in partcle physics

It might be of interest to put some classics and intro level publications on the subject. --IsleScapeTalk 17:19, 8 February 2007 (UTC)

[edit] Non-accelerator physics?

This article is devoted to collider experiments, but other kinds of experiments are surely part of particle physics, too: double-beta decay, searches for dark matter, neutrino oscillation experiments, etc. Don't we need to add a section on that? SchmittM 02:14, 18 March 2007 (UTC)

[edit] evidence for physics beyond the standard model

The articles lists non-zero neutrino masses as evidence for physics beyond the standard model. How about the existence of dark matter and the baryon asymmetry? Neither of these can be explained in the Standard Model and there is absolutely no doubt about the empirical facts... SchmittM 02:14, 18 March 2007 (UTC)

Both of the issues you mention come from astronomical observations. They are evidence that we should find physics beyond the Standard Model, but particle physics hasn't been able to observe dark matter or the full cause of the baryon asymmetry yet. Josh Thompson 07:36, 21 May 2007 (UTC)

[edit] SPIRES

At the moment there's an external link to SPIRES-HEP. Should we get rid of this and make it a wikilink, since SPIRES has its own wiki article? Josh Thompson 07:45, 21 May 2007 (UTC)

[edit] Rewriting the History section

Inspired by the edit by 128.62.92.218, I starting rewriting the history section. Hopefully people are ok with what I have done. There is a lot of later history that could be added, although the section should be kept from getting too long. Josh Thompson 07:17, 26 May 2007 (UTC)

  • I haven't been paying attention to the Wikipedia for a while, and I just came back to discover this edit, which bothers me greatly. The user changed the History section from what I thought was a good starting point to a bunch of stuff about the Greeks and nuclear physics. The user also removed two References. This article should have more references, not less! Does anyone have any opinions on this? Josh Thompson 17:31, 8 November 2007 (UTC)

[edit] Scale of the 'STAR explosion' image

It would be good to show a scale on the the 'STAR explosion' image. Duncan.france (talk) 07:54, 8 December 2007 (UTC)

[edit] Public policy

Do we really need the public policy section? To my knowledge, particle physics isn't very controversial. If it is a serious issue, the public policy section should be moved to Particle accelerator. I'd vote to just remove it though. --Voidxor (talk) 16:59, 24 March 2008 (UTC)