1. NuFact Summer Institute Capri 2005 Eligio Lisi, INFN, Bari, Italy LECTURE I 1+41

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3. The oldest fundamental particle after the electron and the photon (Pauli, 1930) First kinematical properties: spin 1/2, small mass, no charge 2

4. Baptised and quantized within four-fermion effective interaction (Fermi, 1933-34) First dynamical properties: Weak interactions, Fermi constant e np GFGF 3

5. After > 70 years of research we have learned a lot more, e.g., that neutrinos come in three flavors, and that the Fermi interaction is mediated by a charged vector boson W, with a neutral counterpart: the vector boson Z Charged current (  q=1) Neutral current (  q=0) 4

6. Despite great progress, only recently we have got (or can reasonably hope to get “soon”) an answer to some fundamental questions asked in the last century: How small is the neutrino mass ? (Pauli, Fermi, ‘30s) Is the neutrino its own antiparticle? (Majorana, ‘30s) Do s of different flavors trasform (“oscillate”) among them? (Pontecorvo, Maki-Nakagawa-Sakata, ‘60s) In particular, one can give an affirmative -and rather detailed- answer to the last question. Explosion of interest (both expt. and theor.) 5

7. O(10 4 ) neutrino papers in the last decade. Boost after 1998 (evidence for atmospheric oscillations) Number of neutrino papers/year (SLAC-Spires) Many excellent neutrino reviews and books exist. Ask me for refs. or browse the “ unbound ” website: www.nu.to.infn.itwww.nu.to.infn.it Hereafter, I will only touch a few selected topics, and cite literature only occasionally - with apologies to colleagues 6

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9. Fermion currents in the Standard Model SU(2) L x U(1) Y Building blocks: Charges: Gauge bosons (after SSB): 8

10. Fermion currents: Low-energy limit: 9

11. Probing fermion currents with neutrinos 10

12. 1) Probing G F in beta-decay and muon decay 11

13. 2) Probing V-A structure in pion decay 12

14. 3) Probing (T 3 -Qsin 2  W ) NC structure with neutrinos 13

15. Total cross sections: Differential cross sections: “ History ” : 14

16. 4) Probing W-Z interference with neutrinos 15

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18. Fermion masses in the Standard Model 17

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23. Massless and massive (neutral) fermions 22

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32. Majorana neutrinos and neutrinoless 2  decay 31

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35. Neutrino mass terms for ONE FAMILY 34

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40. Neutrino masses for MORE FAMILIES 39

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