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Neutrino Oscillations

Now let's turn to neutrino oscillations. Suppose that the weak eigenstate neutrinos, i.e., the ones that are produced along with a definite lepton in weak transitions, are mixtures of the neutrinos of definite mass,

 

where , , or a sterile neutrinogif . and are mass eigenstates and and are weak eigenstates. In a weak decay one produces a definite weak eigenstate, e.g.,

 

There will then be quantum mechanical oscillations, just as for any two state system. At a later time there will be a probability that the final state

 

is different from the initial one. In particular, there is a survival probability

 

of measuring a ( i.e., a probability 1 - P of disappearance), and a probability

 

of the appearance of the other neutrino flavor. Here is the difference between squared masses, and has been assumed. The last argument can be written as , where is in , L is in m, and E is in MeV.






Mon Nov 27 19:39:39 EST 1995