Exercises for section 4.1.1

% Exercise 1: Delbruck Scattering:

\hskip 0.75in                    % Move the whole picture to the right.
\begin{picture}(10000,10000)(0,0)
\drawline\photon[\SE\FLIPPED](0,5000)[6]   % Start from the upper left.
\double\photonlengthx  \multroothalf\photonlengthx  % mults by root 2.
\drawline\fermion[\E\REG](\photonbackx,\photonbacky)[\photonlengthx]
\drawline\photon[\NE\REG](\pbackx,\pbacky)[6]
\drawline\fermion[\S\REG](\photonfrontx,\photonfronty)[\fermionlength]
\drawline\photon[\SE\FLIPPED](\pbackx,\pbacky)[6]
\drawline\fermion[\W\REG](\photonfrontx,\photonfronty)[\fermionlength]
\drawline\photon[\SW\REG](\pbackx,\pbacky)[6]
\drawline\fermion[\N\REG](\photonfrontx,\photonfronty)[\fermionlength]
\end{picture}


% Exercise 2:  Drell-Yan

\documentstyle [12pt]{report}
\begin{document}
\input FEYNMAN
\begin{center}    %  Everything to be centred.
Drell-Yan W-Production

\begin{picture}(10000,10000)    % Note that the 10000 x 10000 box is centred.
\bigphotons   % needed in 12-pt.
\THICKLINES
\drawline\photon[\E\REG](5000,5000)[11]
\drawarrow[\E\ATBASE](\pmidx,4820)
\put(\pmidx,5800){$W^+$}
\drawline\fermion[\NW\REG](\photonfrontx,\photonfronty)[5500]
\drawarrow[\SE\ATBASE](\pmidx,\pmidy)
\put(3500,7100){q}
\drawline\fermion[\SW\REG](\photonfrontx,\photonfronty)[5500]
\drawarrow[\SW\ATBASE](\pmidx,\pmidy)
\put(3500,2300){$\overline{q}'$}
\drawline\fermion[\NE\REG](\photonbackx,\photonbacky)[5500]
\drawarrow[\SW\ATBASE](\pmidx,\pmidy)
\global\advance \pmidx by -1400
\put(\pmidx,7100){$e^+$}
\drawline\fermion[\SE\REG](\photonbackx,\photonbacky)[5500]
\drawarrow[\SE\ATBASE](\pmidx,\pmidy)
\global\advance \pmidx by -1200
\put(\pmidx,2300){$\nu$}
\end{picture}
\end{center}
\end{document}