set style data line
set label "polar angle resolution" at 1,0.0075
set label "theta = 90 degrees" at 1,0.00720
set label "pos. res. = 150 microns" at 1,0.00690
set label "length of detector = (0.58600 - 0.16895) m" at 1,0.00660
set label "no. of pos. meas. = 10" at 1,0.00630
set label "no. of r. l. = 0.0317" at 1,0.00600
set label "no. of r. l. in front = 0.0212" at 1,0.00570
set label "stereo angle = 6 degrees" at 1,0.00540
set xrange [0.2:2.0]
set yrange [0.00:0.01]
set grid

plot "cdc_pi_polar.txt" using 2:4 title "pion mass", "cdc_p_polar.txt" using 2:4 title "proton mass"