Bend the line to make it more beautiful?

how to bend the line like the first picture and more beautiful. Thanks
I want to combine the letter "l" and "d" together.

documentclass[tikz,border=1pt]{standalone}
usetikzlibrary{arrows,scopes}
begin{document}
begin{tikzpicture}
fill[green, even odd rule] (0,0) circle[radius=6] (0,0) circle[radius=4];
draw [line width=2cm, green,line cap=round] (5,12) --  (5,0);
draw [line width=2cm, green,line cap=round] (-5,12) --  (-5,0);
end{tikzpicture}
end{document}

documentclass[tikz,border=1pt]{standalone}
begin{document}
begin{tikzpicture}
fill[green, even odd rule] (0,0) circle[radius=6] (0,0) circle[radius=4];
draw [line width=2cm, green,line cap=round] (5,0) -- (5,4) to[out=90, in=0] (1.5,10);
draw [line width=2cm, green,line cap=round] (-5,0) -- (-5,4) to[out=90, in=180] (-1.5,10);
end{tikzpicture}
end{document}