The Standard Model

BOSON LEPTON MESON BARYON Photon 0 0 Neutrino 0 0 Electron 0 ±1 Muon 0 ±1 Pion 0 ±1/0 Kaon ±1 ±1/0 Proton 0 +1 Neutron 0 0 Lambda -1 0 Sigma -1 ±1/0 Xi -2 -1/0

The Eightfold Way Meson Octet In 1962 – Gell-Mann organizes the “particle zoo” and proposes the underlying quark structure. To account for the patterns seen. Meson Octet

The Eightfold Way Baryon Octet In 1962 – Gell-Mann organizes the “particle zoo” and proposes the underlying quark structure. To account for the patterns seen. Baryon Octet

Particle Men Murray Gell-Mann and George Zweig proposed independently that mesons and baryons are made up of smaller particles… named QUARKS by Gell-Mann. Gell-Mann Zweig

Quark Flavors Quarks are bound together by the strong force. Quarks possess color charge: “red” “green” or “blue” Quarks combine into color neutral groups – “hadrons” Quarks triplets - “baryons” Quarks pairs - “mesons” (always one quark and one antiquark)

Quark Flavors Quarks are bound together by the strong force. Quarks possess color charge: “red” “green” or “blue” Quarks combine into color neutral groups – “hadrons” Quarks triplets - “baryons” Quarks pairs - “mesons” (always one quark and one antiquark)

Quark Flavors Quarks are bound together by the strong force. Quarks possess color charge: “red” “green” or “blue” Quarks combine into color neutral groups – “hadrons” Quarks triplets - “baryons” Quarks pairs - “mesons” (always one quark and one antiquark)

Quark Flavors Quarks are bound together by the strong force. Quarks possess color charge: “red” “green” or “blue” Quarks combine into color neutral groups – “hadrons” Quarks triplets - “baryons” Quarks pairs - “mesons” (always one quark and one antiquark)

Pions Mass Charge UP QUARK : 1.8 - 3.0 MeV + 2/3 Quark pairs (one quark + one anti-quark). The weak force causes decay with a lifetime of 2.6 x10-8 seconds for charged pions. (or 8.4 x10-17 seconds for neutral pions) Mass Charge UP QUARK : 1.8 - 3.0 MeV + 2/3 DOWN QUARK : 4.5 - 5.3 MeV - 1/3

Pions p+ ud po dd po uu p- du Quark pairs (one quark + one anti-quark). The weak force causes decay with a lifetime of 2.6 x10-8 seconds for charged pions. (or 8.4 x10-17 seconds for neutral pions) p+ ud po dd po uu p- du

Baryons p+ uud + 2/3 + 2/3 - 1/3  +1 no udd + 2/3 - 1/3 - 1/3  0 Protons and Neutrons contain three quarks each. The mass and charge of the nucleons come from the quarks. Mass Charge UP QUARK : 1.8 - 3.0 MeV + 2/3 DOWN QUARK : 4.5 - 5.3 MeV - 1/3 p+ uud + 2/3 + 2/3 - 1/3  +1 no udd + 2/3 - 1/3 - 1/3  0

Baryons p+ uud 3 + 3 + 5.3  11.3 MeV no udd 3 + 5.3 + 5.3  13.6 MeV Protons and Neutrons contain three quarks each. The mass and charge of the nucleons come from the quarks. Mass Charge UP QUARK : 1.8 - 3.0 MeV + 2/3 DOWN QUARK : 4.5 - 5.3 MeV - 1/3 p+ uud 3 + 3 + 5.3  11.3 MeV no udd 3 + 5.3 + 5.3  13.6 MeV

Baryons p+ uud 938 MeV >> 11.3 MeV Protons and Neutrons contain three quarks each. The mass and charge of the nucleons come from the quarks. Mass Charge UP QUARK : 1.8 - 3.0 MeV + 2/3 DOWN QUARK : 4.5 - 5.3 MeV - 1/3 p+ uud 938 MeV >> 11.3 MeV no udd 940 MeV >> 13.6 MeV

Baryons Protons and neutrons contain three quarks each. The mass and charge of the nucleons come from the quarks. p+ uud no udd A neutron can turn into a proton during beta decay. This is caused by the weak force.

Baryons p+ uud no udd p- uud Protons and neutrons contain three quarks each. The mass and charge of the nucleons come from the quarks. p+ uud no udd p- uud A neutron can turn into a proton during beta decay. This is caused by the weak force.

Deltas D++ uuu D+ uud Do udd D- ddd Baryons can exist in short-lived excited states called delta-particles. The strong force causes decay with a lifetime of 5.6 x10-24 seconds. D++ uuu D+ uud Do udd D- ddd

Quark Theory - Recap D++ uuu D+ uud Do udd D- ddd p+ ud po dd po uu Quarks – Fundamental particles in existence since the Big Bang. Possess color charge (R G B) Hadrons – Subatomic particles composed of quarks. Are color neutral. Baryons – Quark triplets ( protons and neutrons are most common ). Mesons – Quark-antiquark pairs ( pions are most common ). Deltas – Excited states of hadrons. D++ uuu D+ uud Do udd D- ddd p+ ud po dd po uu p- du p+ uud no udd

Strange Matter Mass Charge Strangeness UP : 3.0 MeV + 2/3 0 K-mesons (or Kaons) were the first “strange” particles discovered. The slow decay was caused by a quantum property called “strangeness”. Strangeness is possessed by a third quark flavor – “s” Mass Charge Strangeness UP : 3.0 MeV + 2/3 0 DOWN : 5.3 MeV - 1/3 0 STRANGE : 95 MeV - 1/3 1

Strange Matter K+ us Probable Decay Routes Ko ds K+  m+ + nmo K-mesons (or Kaons) were the first “strange” particles discovered. The slow decay was caused by a quantum property called “strangeness”. Strangeness is possessed by a third quark flavor – “s” K+ us Probable Decay Routes Ko ds K+  m+ + nmo K+  p+ + po ho ss K+  p+ + p+ + p-

Strange Matter Mesons Baryons K+ us Lo uds Xo uss Ko ds S+ uus X- dss Heavier “strange” baryons (hyperons) were also discovered. Double-strange and triple-strange particles must lose one unit of strangeness in each decay. Mesons Baryons K+ us Lo uds Xo uss Ko ds S+ uus X- dss So uds ho ss S- dds W- sss

The Eightfold Way Baryon Decuplet In 1962 – Gell-Mann organizes the “particle zoo” and proposes the underlying quark structure. To account for the patterns seen. Strangeness (-3) Mass (1672 MeV) Theorized Baryon Decuplet

W- Discovered 1964 Brookhaven, NY

W- Discovered 1964 Brookhaven, NY

BOSON LEPTON MESON BARYON Photon 0 0 Neutrino 0 0 Electron 0 ±1 Muon 0 ±1 Pion 0 ±1/0 Kaon ±1 ±1/0 Proton 0 +1 Neutron 0 0 Lambda -1 0 Sigma -1 ±1/0 Xi -2 -1/0

BOSON LEPTON HADRONS QUARK MESON BARYON Photon Neutrino Electron Muon Up Down Pion 0 ±1/0 Strange Kaon 1 ±1/0 Proton 0 +1 Neutron 0 0 Lambda 1 0 Sigma 1 ±1/0 Xi 2 -1/0 Omega 3 -1

Leptons Mass Charge ELECTRON: 0.511 MeV ± 1 Electrons do not contain any quarks. Electrons are not affected by the strong force. Mass Charge ELECTRON: 0.511 MeV ± 1 NEUTRINO: > 1.2 x10-7 MeV 0 MUON: 106 MeV ± 1

Leptons Mass Charge ELECTRON: 0.511 MeV ± 1 Electrons do not contain any quarks. Electrons are not affected by the strong force. Mass Charge ELECTRON: 0.511 MeV ± 1 NEUTRINO: > 1.2 x10-7 MeV 0 MUON: 106 MeV ± 1 TAU: 1777 MeV ± 1 (Discovered in 1975 by M. Perl - mean lifetime of 3 x10-13 seconds.)

BOSON LEPTON HADRONS QUARK MESON BARYON Photon Neutrino (e, m, t)  exists as three-fold quantum mix Electron Muon Tau Up Pion 0 ±1/0 Down Kaon 1 ±1/0 Strange Proton 0 +1 Neutron 0 0 Lambda 1 0 Sigma 1 ±1/0 Xi 2 -1/0 Omega 3 -1

Pions: Production & Decay. m+ p+

Strange Matter Mass Charge UP : 3.0 MeV + 2/3 DOWN : 5.3 MeV - 1/3 K-mesons (or Kaons) were the first “strange” particles discovered. Mass Charge UP : 3.0 MeV + 2/3 DOWN : 5.3 MeV - 1/3 STRANGE : 95 MeV - 1/3 CHARM : 3,097 MeV 0 BOTTOM: 4,180 MeV - 1/3 TOP: 172,440 MeV + 2/3

Neutral Pion: Production & Decay. g K- po g e- p- e-

The Positron: Antimatter . . e+