t b e - d -1/3 4/18/2016 Particle Classification 3 Generations of Leptons and Quarks Standard Model

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1 PHYS 342 Moern Physics Elementary Particles an Stanar Moel II Toay's Contents: a) Particle Collier b) Stanar Moel of Elementary Particles c) Fiel Bosons: qantization of for basic forces ) Higgs Boson: origin of mass e) Leptons an Qarks: fnamental material particles f) Mesons an Baryons: composite material particles g) Conservation Laws in particle physics h) Energy an Momentm in particle collision i) Particle Physics beyon Stanar Moel Particle Classification Harons are NOT elementary particles, an they are composite particles mae p by qarks. mesons are bosons an harons. baryons are fermions an harons. Stanar Moel 3 Generations of Leptons an Qarks the fnamental biling blocks of matter 1 st generation 2 n generation 3 r generation e e - +2/3 - +2/3 +2/3 c s -1-1/3-1/ Orinary matter Cosmic rays Accelerators t b -1/3 Leptons an Qarks have three generations: from low energy to high energy 1

2 Leptons an Qarks: spin-1/2 Fermions Qark Mass 3 generations are similar in everything bt the mass Mass 1 (GeV) E= mc 2 1 proton mass ~ 1GeV (1-27 Kg) Qarks Up Down Strange Charm Bottom Top GeV The mass grows larger in each sccessive family Top (iscovere 1995) Antiparticles for Leptons an Qarks Orinary Matter For every fnamental particle of matter, there is an anti-particle with same mass an properties bt opposite charge Matter e e /3-1/3 Anti-Matter e +1 e + positron -2/3 +1/3 Bar on top to inicate anti-particle Corresponent anti-particles exist for all three generations All anti-particles have been proce sing accelerators Leptons: netrino e = electron charge e e /3-1/3 Qarks: = p = own All stable(natral) matter aron s can be escribe sing first generation: electrons, netrinos, an qarks 2

3 Orinary Matter: Netrino Is the orinary niverse mae only of qarks an electrons? Electron, proton an netrons are rarities! For each of them in the Universe there is 1 billion netrinos Netrinos are the most abnant matter-particles in the Universe! Within each cm 3 of space: ~3 netrinos from Big Bang 1 cm 1 cm Netrinos are everywhere! in the oter space, on Earth, in or boies.. Orinary Matter: Netrino ner the Sn Every cm 2 of Earth srface is crosse every secon by more than 1 billion (1 1 ) netrinos proce in the Sn 14 netrinos per secon from Sn are zipping throgh yo No worries! Netrinos o not harm s. Or boies are transparent to netrinos Within yor boy at any instant: roghly 3 million netrinos from the Big Bang Orinary Matter: proton an netron Qarks have fractional electric charge! electric charge + 2/3 electric charge 1/3 proton (charge +1) netron (charge ) Qark Colors All qark flavors come in 3 versions, calle colors p own +2/3-1/3 Qarks combine together to form colorless particles -Baryons (three qarks: re+ green + ble = white) proton p Strong forces gle qarks together in bon states p n Mesons (qark-antiqark pair) sch as re + anti-re -bar state pion 3

4 Qarks have more qantm nmbers Qarks bil colorless Meson or Baryons Charge, Spin, Color Also: Baryon, Charm, Strangeness, Topness, Bottomness (like spin an charge, they are intrinsic properties!) c c J/ b b Y B mesons (bq) b b B - B + b b B B Many more mesons an baryons More Mesons More Baryons 4

5 "Yong man, if I col remember the names of these particles, I wol have been a botanist! E.Fermi to his stent L. Leerman (both Nobel lareates) The Particle Physicist s Bible: Particle Data Book Most particles are not stable an can ecay to lighter particles.. Conservation Laws in Particle Physics 1) Conservation of Energy 2) Conservation of Linear Momentm 3) Conservation of Anglar Momentm 4) Conservation of Electric Charge 5) Conservation of Ncleon Nmber 5) Conservation of Lepton Nmber 6) Conservation of Baryon Nmber 7) Conservation of Flavor Nmber (Flavoers incling Charm, Strangeness, Topness, Bottomness) 8) Conservation of some symmetries (charge-time-parity.) Nclear Reaction Energy an Momentm in particle collision 1) release energy is efine as the ifference of the rest mass between the initial particles an the particles proce after collision. ) 2) The release energy is share as kinetic energy of the particles proce after collision. Beyon the Stanar Moel 3) Relativistic Treatment is Manatory in particle physics 5

6 One Theory for the whole Universe GRAVITY UNIFIED FORCE? ELECTRO- MAGNETIC STRONG WEAK Looking for a simple elegant nifie theory ICP 42 the last one ICP 42: What is the maximm kinetic energy of the positron emitte in the ecay of a rest antimon? Step : Accoring to what yo have learne, what is the rest energy of netrino approximately? An what is the relation between netrino energy an its momentm. Step1: What is the release energy Q of the ecay? Step2: What oes this release energy convert to? Step3: To make the positron have the maximm kinetic energy, how o the netrinos move an how mch energy o the netrinos carry? (Can netrino takes zero energy? Why?) Step4: Accoring step 3, yo have two eqations. What are the two eqations? Step5: From the two eqations, get the maximm kinetic energy of the positron. Bt enless physics avances 36 people,13 teams, loss one! Monay: 1. Ulazimir Kasacheski, Jonathan Brown, an Vishal Patel, interview researchers at IUPUI 2. Lif Wang, Weiyan Deng, an Yfeng Zhang, Moern Experiments to Test Special Relativity 3. Stevie Bastin, Stjepan Kraljic, Zack Rowe, Gravitational wave/gravitons 4. Hongkn Zh, Giming Chen, an Jiawen Wang, First gravitational wave observation 5. Chanyi Chen, Zihao F, an Lingbin Meng, Introction to General Relativity 6. Chase Howar an Alex Canner, Gravitational lensing Wenesay: 7. Zongying X, Zheng Hang, an Jiani Xie, Blackboy Raiation 8. Dalton Eaton, Robert McKay, an Gy Wiss, Monte Carlo Simlation of Schroinger eqation 9. Aaron Boehm, Joseph Sorco, an Will Simms, Atomic physics explanation of helim laser 1. Josiah Alstott, Thomas Freestone, an Ross Wallgren, Atomic clock 11. Kailiang Chen, Zhong Jin, Peiming Zh, Qantm Information 12. Tianyang W, Haizhen Xie, an Bingcheng Zho, Netrino physics 13. Ryan, Particle Accelerator LHC 6