deletions | additions       diff --git a/kinematics.tex b/kinematics.tex  index 43f5cc8..02a17e8 100644  --- a/kinematics.tex  +++ b/kinematics.tex 
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\mathbf{\pi^{+}} = \mathbf{\mu^{+}} + \mathbf{\nu_{\mu}}  \end{equation}  Where $\mathbf{\pi^{+}}$, $\mathbf{\mu^{+}}$, and $\mathbf{\nu_{\mu}}$ are the energy-momentum 4-vectors. It Since the magnitude of a 4-vector  is important to note that a Lorenz invariant,  one canalways  boost to the rest frame of the particle where $\vec{p} = 0$ and a find the value for $\mid \mathbf{p} \mid ^2$, where $\mathbf{p}$ is its energy momentum 4-vector. Since in ^2$. In  natural units units,  \begin{equation}  E^2 = \vec{p}^2 + m^2  
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\end{split}  \end{equation}  Since $\mid \mathbf{p} \mid^2$ is a Lorentz invariant, this is the magnitude of the 4-momentum for all time. Since the The  neutrinos mass is many ordered orders  of magnitude smaller than that of the other particles \cite{Robertson_2008}, so  we can set \begin{equation}  \begin{split}  \mathbf{\nu_{\mu}}^2 &= m_{\nu} \\  &\implies  \mathbf{\nu_{\mu}} = 0 \end{equation}