Consider the neutrinos produced by two decay channels: $$ \pi^+ \rightarrow \mu^+ +\nu_\mu\,, \qquad\qquad K^+ \rightarrow \mu^+ +\nu_\mu\,. $$ with $\pi$ decay being 10 times more likely than $K$ decay.
In a real experiment(e.g. MiniBooNE), the decay from both contributions are measured. How can one differentiate between the neutrinos and the K neutrinos?
It seems really hard to find a starting point to tackle this problem, is it achieved by assuming that the theory behind such decays is able predict the relative peak position of each distribution?
Note: I have virtually zero background knowledge in particle physics, this question is part of my research project.
Edit: This plot is from my own simulation so there is no source for it. However, my lecturer says that the project is based on a paper predicting MiniBOONE's neutrino fluxes, with the following instructions: