## Elementary Particles Presented

Standard Model : SU(3)xSU(2)xU(1) gauge theory
Gauge bosons : 8 SU(3) color-coupled gluons, 3 SU(2) 2 W\'s and 1 Z-boson, 1 U(1) B the foton

In the unbroken SU(2)xU(1) gauge theory of the electroweak interactions, there are four fields. These fields are usually called W1, W2, W3, (from SU(2)) and B (from U(1))

After spontaneous symmetry breaking due to the Higgs mechanism, you still have four fields, but three of them gain masses. The W1 and W2 mix to form the W+ and W- and the W3 mixes with the B to form the Z0. The rest of the W3-B mix remains massless and is the photon (often called A and belonging to the remnant U(1) symmetry of QED).

Three generations of spinor fermions divided into:
1) colored doublet left-quarks (ups and downs)
2) doublet left-leptons (electrons and neutrinos)
3) colored right-ups
4) colored right-downs
5) right-electrons
with various hypercharges

The singlet states correspond to particles that don't feel the weak force like 3,4 and 5...

Or you can classify like this :

Mass Particles

---A. Six quarks
------1. Up, down, strange, charm, top, bottom
------2. Combine to form Hadrons in two varieties: baryons, mesons

---B. Six leptons
------1. Three with charge (Tau, muon, electron)
------2. Three neutrinos each corresponding to a charged lepton
------3. Decay, don't combine

II. Three types of interactions mediated by force particles

---A. Strong (gluons)
---B. Electroweak
------1. Electromagnetic (photon)
------2. Weak (Z, W+, W- bosons)
---C. Gravity (graviton?)

Can you understand "the why" of this classification ?
marlon

Blog Entries: 6
Recognitions:
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 Quote by marlon ---A. Six quarks ------1. Up, down, strange, charm, top, bottom ------2. Combine to form Hadrons in two varieties: baryons, mesons ---B. Six leptons ------1. Three with charge (Tau, muon, electron) ------2. Three neutrinos each corresponding to a charged lepton ------3. Decay, don't combine Can you understand "the why" of this classification ? marlon
No.

I can not understand why the leptons are classified according electric charge, but the quarks are not.

 Recognitions: Homework Help Science Advisor The quarks are classified like the leptons. The quarks come in 3 doublets. (u,d),(c,s),(t,b). In each doublet the upper quark has a charge +e more than the lower quark. This is just like the leptons. Details are related to the groups involved. The group structure is S(3)XSU(2)XU(1). Why the quarks are +2/3 and -1/3 is involved with hypercharge and group details. If the GUT is SU(5), the breakdown into this structure is unique, but th proton decays.
 Here is a nice introductory story on the Top Quark, presented by Fermilab http://www-ed.fnal.gov/samplers/hsph...ent/index.html Also check out my TOP QUARK entry in my journal : http://www.physicsforums.com/journal...90&action=view regards marlon
 Admin Some useful information regarding particles. Fermions Fermi-Dirac Statistics Pauli Exclusion Principle Bosons Bose-Einstein Statistics Spin Quantum Electrodynamics (QED) Quantum Chromodynamics (QCD) Quantum field theory (QFT)
 Admin This is a cool website if your into Particle Physics - which I am among many other things - but I have to get up to speed on QCD, QFT, GUT and other things. Stanford Linear Accelerator Center Virtual Visitor Center Also - High Energy Cosmic Rays Electron Gamma Shower Have fun! Hey, Marlon - you were looking for physics opportunities in California. Well - here is one, but it is a bit of drive down to Hollywood!
 Admin Some short articles on particle physics from American Institute of Physics - Physics News - http://newton.ex.ac.uk/aip/catagorie...e_physics.html
 Admin I search for this but I didn't find it in this thread. Summary Tables in the 2002 Review of Particle Physics http://pdg.lbl.gov/2002/contents_tables.html
 Admin News from the particle physics world - http://www.interactions.org/cms/
 Check THIS SITE if you wanna find out more on the concept of asymptotic freedom in QCD. You need to click on "Nobel Lectures" to read what the 2004 Nobel Laureates in Physics have to say on it. PS : Did you guys know that the guy in the middle actually played in a movie with Paul Newman ? regards marlon
 If you wanna have a very introductory lesson in renormalization theory of the weak interaction, just read the Nobel Lecture of Gerardus 't Hooft, the 1999 Physics Nobel Prize Laureate. Enjoy regards marlon
 Admin Deutsche Physikalische Gesellschaft e.V. http://www.dpg-physik.de/ http://www.dpg-tagungen.de/index.html - auf Deutsch http://www.dpg-tagungen.de/index_en.html - English ein Beispiel / example - http://www.dpg-tagungen.de/archive/2...koeln_prog.pdf
 Admin WS 05/06 No. 6811 Ian C. Brock http://www-zeus.physik.uni-bonn.de/~...ng/vtp_ws0506/
 Admin This is really cool! http://geant4.cern.ch/G4UsersDocumen...nceManual.html
 Admin Researchers report the first direct observation of the strange b baryon Xi_b^{-} or $$\Xi_b^{-}$$ http://www.arxiv.org/abs/0706.1690 $p\bar{p}$ collisions at $\sqrt{s}$ = 1.96 TeV. For more publications related to the D0 experiment. http://www.arxiv.org/find/hep-ex/1/a.../0/1/0/all/0/1
 Hi everyone, I was earlier today searching for online video material for students who asked me where to find it. I admit that such lectures are much more pleasant to follow than textbooks, although I myself never find the need for video material. The best would be to actually be able to attend the lecture interactively. In any case, it did not occur to me at first, but CERN as an amazing server full of countless presentations on all sorts of topics. Soome of them of incredible value. You will find them by browsing their web server. Enjoy Praising thanks to this wonderful initiative.