Introduction to the Standard Model of Particle Physics

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Part I 1. Introduction: A Universe of Fermionic Matter bound by Bosonic Fields 1 Part I Phenomenology of Elementary Particles 1 Introduction: A Universe of Fermionic Matter bound by Bosonic Fields A long series of experiments and theoretical studies and advances has established the so-called Standard Model of elementary particle physics. This theory encompasses the electromagnetic theory (unified by Maxwell), the weak interaction (responsible for radioactive decays of for instance the neu- tron and the muon, and for the burning of hydrogen into helium and heavier elements in the Sun), and the strong interaction (which binds protons and neutrons inside the nucleus). We know that the Standard Model in incomplete, in that it does not describe the, much weaker, gravitational interaction in the same quantum mechanical framework, because a number of features are not understood in the model, and, finally, because calculations break down at energies of a few TeV, energies which will become accessible by 2005 at the Large Hadron Collider being built at CERN near Geneva. However, all present data are in excellent agreement with predictions made within the frame- work of the Standard Model, and it is the best theory we have at present. Many famous and less famous physicists, both experimenters and theorists, have contributed to the present picture of the elementary particles, which developed from the early 1900s till now. The Standard Model is thus the result of a long and arduous search for the correct description of nature at its most elemental level. In that search, experimental study and theoretical insight always go hand-in- hand: theory tends to diverge if not checked by experimental feedback, and experimentation becomes meaningless without theoretical analysis of its findings. We expect that the next generation of experi- ments, at the Fermilab Tevatron and at the CERN LHC will result in exploration of the physics beyond the Standard Model. The Standard Model divides the world of elementary particles in fermionic matter, leptons (6 electron-like particles, and 6 anti-leptons) and quarks (6 quarks of different flavors, and 6 anti-quarks), see Table 1. The fermions are the sources of a variety of fields: interactions between the leptons and quarks are mediated by Intermediate Vector Bosons , listed in Table 2. Table 1. Elementary matter Fermions Spin ½ Matter Fermions (Mass [MeV]) Baryon / Lepton number B L Electric- Charge Q [e] Weak Isospin I 3 Weak Hyper- charge Y 2(Q I 3 ) ν (eutrino) e (< 1eV) ν (eutrino) µ (< 1eV) ν (eutrino) τ (< 1eV) 0 1 0 + 1 / 2 e (lectron) (0.511) µ (uon) (105) τ (au) (1680) 0 1 1 1 / 2 1 u (p) ( 3) c (harm) ( 1.5 × 10 3 ) t (op) ( 174 × 10 3 ) 1 / 3 0 + 2 / 3 + 1 / 2 d (own) ( 3) s (trange) ( 0.3 × 10 3 ) b (ottom) ( 5 × 10 3 ) 1 / 3 0 1 / 3 1 / 2 + 1 / 3
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Part I 1. Introduction: A Universe of Fermionic Matter bound by Bosonic Fields 2 Leptons have no strong interaction. The neutral
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/05/2008 for the course PHY 557 taught by Professor Rijssenbeek during the Fall '00 term at SUNY Stony Brook.

Page1 / 4

Lecture 01 - Part I 1. Introduction: A Universe of...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online