How to change the following tex code in order that the "(" and ")"
of the matrix are of same size as the "(" and ")" of the \nu vectors ?

So far, I do :

```
\begin{equation}
\left(
\begin{array}{c}
\nu_e\\
\nu_{\mu}\\
\nu_{\tau}
\end{array}
\right)
=
\left(
\begin{array}{ccc}
\\
\multicolumn{3}{c}{\vspace{0.33cm}PMNS}\\
\multicolumn{3}{c}{\vspace{0.33cm}matrix}\\
\end{array}
\right)
\left(
\begin{array}{c}
\nu_1\\
\nu_2\\
\nu_3
\end{array}
\right)
\end{equation}

```

but this is not satisfactory since the parentheses of the matrix extend too much on the top and the bottom.

[![enter image description here](https://i.stack.imgur.com/UOyiG.png)](https://i.stack.imgur.com/UOyiG.png)

My goal is to have this style (grabed on the web):
[![enter image description here](https://i.stack.imgur.com/A0oAU.png)](https://i.stack.imgur.com/A0oAU.png)