[Tex/LaTex] How to select the style of a lowercase gamma

Question

It is traditional in Physics to use a lowercase gamma that looks like a Y. Without going into the question of whether that tradition is wrong, how do I differentiate in math mode Latex markup between a Gamma that looks like a Y and a Gamma with a loop?

No, I do not mean either capital or upright.

I'd prefer avoiding Unicode unless ArXiV now supports xetex.

I don't know how to insert the PDF as an image, but http://mason.gmu.edu/~smetz3/humor/dirac.pdf is generated from

\documentclass{article}
\usepackage{bm}
\usepackage[paperheight=10in,paperwidth=10in,top=0.75in, bottom=0in,   left=0in, right=0in]{geometry}
\usepackage{graphicx}
\begin{document}
\pagestyle{empty}

\vspace{.5in}

\begin{center}
{\Huge \bfseries Which part of}
\end{center}

\vspace{1.75in}

{\Huge
  \[
    \bm{(\gamma^{\mu } (i\hbar \partial _{\mu } - {\frac {e}{c}}A_{\mu })-mc) \psi =0}
  \]
}

\vspace{1.75in}

\begin{center}
{\Huge \bfseries don't you understand?}
\end{center}
\end{document}

Answer 1

Please choose one of these.

\documentclass[a4paper]{article}
\usepackage{tipa}
\usepackage{upgreek}
\begin{document}

\begin{tabular}{rl}
tipa:    & \textbabygamma\\
upgreek: & $\upgamma$\\
tipa:    & \textgamma\\
tipa:    & \textramshorns\\
default: & $\gamma$\\
\end{tabular}

\end{document}