1. Particle Physics Probes Messengers of the Universe J. Brunner

2.  Feel only weak interactions  Give access to about half of the free parameters of the standard model  Only neutral elementary fermions

4. Family Strong Electromagnetic Weak 1ude e 2csµ µ 3tb 

5. Family Strong Electromagnetic Weak 1ude e 2csµ µ 3tb  Color charged Q = +2/3

6. Family Strong Electromagnetic Weak 1ude e 2csµ µ 3tb  Color charged Q = -1/3

7. Family Strong Electromagnetic Weak 1ude e 2csµ µ 3tb  Color neutral Q = -1

8. Family Strong Electromagnetic Weak 1ude e 2csµ µ 3tb  Color neutral Q = 0

9. Family Strong Electromagnetic Weak 1ude e 2csµ µ 3tb  m u < m c < m t

10. Family Strong Electromagnetic Weak 1ude e 2csµ µ 3tb  m( e ) < m( µ ) < m(  )

11. Family Strong Electromagnetic Weak 1ude e 2csµ µ 3tb  m( e ) < m( µ ) < m(  ) ? ?

12. Family Strong Electromagnetic Weak 1ude 1 2csµ 2 3tb 3 m( 1 ) < m( 2 ) < m( 3 ) “Normal”

13. Family Strong Electromagnetic Weak 1ude 3 2csµ 1 3tb 2 m( 3 ) < m( 1 ) < m( 2 ) “Inverted”