Have they ...?

New users should check this forum first. Say hi.
Post Reply
CuriousAmerican
Posts: 1
Joined: Thu Apr 26, 2012 5:29 am

Have they ...?

Post by CuriousAmerican » Thu Apr 26, 2012 5:33 am

(3) questions:

A) Have they discovered a real monopole in spin ice, or just some phenomenon that simulates a monopole?

B) Did they discover the Higgs Boson yet?

C) What other particles are left to discover?

User avatar
DCWhitworth
LHCPortal Guru
Posts: 585
Joined: Mon Nov 30, 2009 8:13 am
Location: Norwich, UK

Re: Have they ...?

Post by DCWhitworth » Thu Apr 26, 2012 12:45 pm

CuriousAmerican wrote:(3) questions:

A) Have they discovered a real monopole in spin ice, or just some phenomenon that simulates a monopole?

B) Did they discover the Higgs Boson yet?

C) What other particles are left to discover?
A. Not that I know of.

B. If they had you'd know all about it.

C. Who knows ? The Higgs is the only fundamental particle from the Standard Model that hasn't been discovered (assuming it exists), but the SM isn't guaranteed to be right or completely inclusive. There are probably hundreds of theories about other particles that might be out there, but they are just that - theories. That's one reason why they're running the LHC, to find out what's out there.

Although it may not have discovered a heck of a lot of stuff it has definitely progressed physics by ruling out a heck of a lot of the theoretical models that have been postulated.
DC

The LHC - One ring to rule them all !

User avatar
CharmQuark
Site Admin
Posts: 1486
Joined: Fri Dec 04, 2009 2:22 am
Location: Berwick-Upon-Tweed (UK)

Re: Have they ...?

Post by CharmQuark » Thu Apr 26, 2012 6:05 pm

CuriousAmerican wrote:(3) questions:

A) Have they discovered a real monopole in spin ice, or just some phenomenon that simulates a monopole?

B) Did they discover the Higgs Boson yet?

C) What other particles are left to discover?


A) Would be awesome if they had ;)

B) I am hoping they don't, it will make it more interesting :thumbup:

C) Loads :D
Anyone who doesn't take truth seriously in small matters cannot be trusted with large ones either by Albert Einstein.

User avatar
chriwi
LHCPortal Guru
Posts: 403
Joined: Fri Nov 20, 2009 1:19 pm
Location: Stuttgart Germany
Contact:

Re: Have they ...?

Post by chriwi » Fri Apr 27, 2012 5:40 am

B:

They found some events that could indicate that a higgs was created, but up to now they are only to 99% sure that any of this events show a real Higgsboson and there is still the chance that what they saw was only a part of the background noise.

the whole proof of the Higgs will be a statistical thing anyways:
1. the will find a certain number of events that could show the decay of a Higgboson (nothing else can be seen anyways, eespecially not the Higgsboson itselfe)
2. they consider in what whays such promissing events can be created in backgroundnois without involving the Higgs. They know the probabbility of such background nois-events pretty well and so they can calculate how many of such events should occur in a certain number of collissions.
3. If the number of promissing events exeeds the calculated number significantly then there must be a new effect not considered above responsible for this increased number of events. They will say a Higgsdecay or anything else they not yet know must be responsibele for this increased number of events.
4. Sionce they have no other idea they will say they found the Higgsboson

Up to now the probability that it is not an accidental accumulation of events in backgroud noiss (like a doubble win on a lotterey(not impossible but highly improbable)) is around 99% but this is not considered to be significant enough to be sure, to say that they are sure they found the Higgs they net a probability with 4 or 5 more 9s after the decimalpoint (99.9999% or 99.99999%) and they hope to get this with this years run.

Afterall they can never be 100.000000000% sure that they ever really found it, but that is normal for particlephysics and doesnt disturb anyone.

Pleas tell me in case I am wrong.
bye

chriwi

Harbles
LHCPortal Guru
Posts: 314
Joined: Sat Nov 28, 2009 10:22 pm
Location: Mississauga, Ontario. Canada

Re: Have they ...?

Post by Harbles » Fri Apr 27, 2012 3:17 pm

Re: C)

The number of unknown particles is by definition unknown. However whatever that number is you can scratch one off the list;
http://www.sciencedaily.com/releases/20 ... 095621.htm

" In the course of proton collisions in the LHC at CERN, physicists Claude Amsler, Vincenzo Chiochia and Ernest Aguiló from the University of Zurich's Physics Institute managed to detect a baryon with one light and two heavy quarks. The particle Xi_b^* comprises one "up," one "strange" and one "bottom" quark (usb), is electrically neutral and has a spin of 3/2 (1.5). Its mass is comparable to that of a lithium atom. The new discovery means that two of the three baryons predicted in the usb composition by theory have now been observed. "

User avatar
PhilG
Posts: 135
Joined: Sun Dec 06, 2009 9:58 pm
Contact:

Re: Have they ...?

Post by PhilG » Fri Apr 27, 2012 6:18 pm

A) These are emergent particles, collective behaviour in condensed matter systems. They can't exist in this form outside if spin ice. Real fundamental magnetic monopoles may well exist according to some GUT theories. They are expected to be too heavy to produce at the LHC but the experiments still search for them just in case.

B) Not yet. If you combine the significance of ATLAS, CMS and CDF and D0 you get a local 4-sigma significance at 125 GeV. This means that the probability of getting such a strong signal if there were no Higgs boson at that mass would be one in 3000. 5-sigma is officially required for discovery and they may only be happy once ATLAS and CMS have that seperately.

C) The only way we can know what is left to discover is by discovering it and then it is no longer left to discover.

Post Reply