How can I make the height of summation and fraction the same?

Question

I was wondering if I could get some help with this. I want to align the heights of fraction and the summation. The summation is positioned too low compared to the fraction. How can I acheive this?

\documentclass[12pt,a4paper]{article}
\begin{document}
\[\Lambda_{entry} =\frac{\psi/(1-\delta)}{\psi/(1-\delta) + m_{I}} + \frac{m_{I}(1-\Phi)}{\psi/(1-\delta) + m_{I}} \sum^{}_{(\tilde{g},\tilde{b}) \in \{(g,b)\}}\hspace{0.1em}f_{\tilde{g},\tilde{b}-1}\]
\end{document}

Answer 1

I hope something like the highest point of the summation [symbol] is aligned with the highest point of the fraction.

Be careful what you ask for...

\documentclass{article}
\usepackage{mathtools} % for '\mathclap' directive
\usepackage{graphicx}  % for '\scalebox' directive
\newcommand{\bigsum}{%
  \mathop{\vcenter{\hbox{\scalebox{1.5}{$\displaystyle\sum$}}}}}
  
\begin{document}

\[
\Lambda_{\mathrm{entry}} =
  \frac{\psi/(1-\delta)}{\psi/(1-\delta) + m_{I}}
+ \frac{m_{I}(1-\Phi  )}{\psi/(1-\delta) + m_{I}} \times
  \bigsum_{\mathclap{(\tilde{g},\tilde{b})\in\{(g,b)\}}}
  f^{}_{\tilde{g},\tilde{b}-1}
\]

\end{document}

Answer 2

\documentclass[12pt,a4paper]{article}
% https://tex.stackexchange.com/a/546690
\newcommand\vc[1]{\vcenter{\hbox{#1}}}
\begin{document}
\[\Lambda_{entry} =
  \frac{\psi/(1-\delta)}{\psi/(1-\delta) + m_{I}} +
  \frac{m_{I}(1-\Phi)}{\psi/(1-\delta) + m_{I}}
  \hspace{0.3em}
  \vc{$\displaystyle\sum_{(\tilde{g},\tilde{b}) \in \{(g,b)\}}
    \hspace{-1em}
    f_{\tilde{g},\tilde{b}-1}$}
\]
\end{document}