Created page with "Quarks: Spin of 1/2, Charge of +-1/3, +-2/3. Quarks experience all four fundamental interactions. By virtue of the strong interaction mediated by gluons (QCD), quarks are hadr..."
New page
Quarks: Spin of 1/2, Charge of +-1/3, +-2/3. Quarks experience all four fundamental interactions. By virtue of the strong interaction mediated by gluons (QCD), quarks are hadronized -- confined to hadrons. Within hadrons, they enjoy asymptotic freedom.
===Top quark===
* 175GeV, +2/3. EXCEPT the top quark, whose lifetime is too short to be mediated by gluons, and is thus always observed bare
===Strong nuclear force===
* Repulsive at small distances (~.7fm), attractive at larger distances (through 2.5fm), falls off to 0
** This repulsion gives nucleons their "size"
* Mediated by gluons between quarks.
* Holds quarks together in hadrons, nucleons together in nucleus.
** Other quarks are only oberved confined
** Their presence is indicated by deep inelastic scattering experiments
*** Color is white, charge is not
==Fermions==
* Half-integer spin, Fermi-Dirac statistics (Pauli Exclusion Principle)
* All leptons
* 3-quark hadrons (baryons)
===Leptons===
Fundamental (not made of quarks, pointlike) fermions.
====Charged (Electron-like)====
Massive.
* Electron / positron
* Muon / antimuon
* Tau / antitau
====Neutral (Neutrinos)====
At least two of these are massive.
* Neutrino / antineutrino
* Tau n/an
* Muon n/an
==Bosons==
* Integer spin, Bose-Einstein statistics (no Pauli Exclusion Principle)
* 2-quark hadrons (mesons)
===Photon===
===W/Z Bosons===
* Mediators of the weak nuclear force
===Gluons===
===Higgs Boson===
===Graviton (predicted)===
==Hadrons==
* Color confinement: hadrons must be "white"
** Quark of a color with anti-quark of the other color
** Three quarks (or antiquarks) of different colors
* Made of quarks, held together by strong force mediated by gluons
** Mesons: Bosons (one quark + one antiquark -> integer spin)
** Baryons: Fermions (three quarks -> half-integer spin)