33-2 - Q Where do neutrinos come from Radioactive decays...

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

View Full Document Right Arrow Icon
Q: Where do neutrinos come from? Radioactive decays = 'weak nuclear force' in action – Example: beta decay of neutron 'beta ray' = old term for electron another example: muon decay neutron (lepton number = 0) proton (lepton number = 0) electron (lepton number = +1) Anti- ν (lepton number = -1) (must be anti to conserve lepton #) μ - (lepton number = +1) ν (lepton number = +1) electron (lepton number = +1) Anti- ν (lepton number = -1) lepton number = conserved physical property (new kind of 'charge') that only leptons have
Image of page 1

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

View Full Document Right Arrow Icon
Q: Who said we need them? Wolfgang Pauli, 1930~33 – If β -decay of nuclei produces only 2 particles (electron and daughter nucleus), it does not seem to conserve momentum! Emitted electrons can have any energy up to maximum allowed by conservation of energy (E MAX = [parent mass - daughter mass]*c 2 ) Pauli: There must be a neutral, ~ massless 3rd particle emitted
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern