hello! could you help me to draw this diagram in latex?

Question

quiver diagram in latex drawing

Answer 1

You can use tikz-cd:

\documentclass{article}
\usepackage{tikz-cd}

\begin{document}

\[
\begin{tikzcd}
&
2 \arrow[dl,swap,"\beta"]
\\
1 \arrow[rr,shift left,"\lambda"]
  \arrow[rr,shift right,swap,"\mu"]
&&
3 \arrow[ul,swap,"\alpha"]
  \arrow[loop,out=30,in=330,looseness=10,"\gamma"]
\end{tikzcd}
\]

\end{document}

Answer 2

The original appears to have been done using xy-pic.

\documentclass[border=5mm]{standalone}
\usepackage[all]{xy}
\begin{document}
\xymatrix@C=1in{
& 
2 
\ar @<-.5ex> [dl]_\beta 
& 
\\
1 
\ar @<+.5ex> [rr]^\lambda 
\ar @<-.5ex> [rr]_\mu 
&& 
3 
\ar @<-.5ex> [lu]_\alpha
\ar @(ur,rd) []^\gamma
\\
}
\end{document}

Try texdoc xypic for more documentation, or follow the link above.