1. Particle Zoo & Classification Schemes

2. Conservation Rules 1. Charge 2. Baryon Number 3. Lepton Number (by flavor) 4. Strangeness 5. Angular Momentum 6. Energy

3. ConcepTest #92 The diagram shows Strangeness vs. Charge for a group of spin 3/2 baryons, similar to a plot that Gell-Mann made. What are the properties of the missing particle for this pattern?      **  *  ** ** **     S Q   ~1385 ~1530 ~1240 Mass (MeV/c 2 ) 1. Q = 0, S = –3 2. Q = +1, S = –3 3. Q = –1, S = –3 4. Q = –2, S = 0 5. Q = –1, S = –2 6. Q = +2, S = –1 What is the mass of this particle? What is the identity of this particle?

4. ConcepTest #93 The table summarizes the properties of the up, down, and strange quarks. A hadron has the following quark content: (uud). Which of the following could this hadron be? Hold up as many cards as necessary. Quark Content for: Negative Pion (   )? Delta-plus-plus (  ++)?