Hi Maria, you will need a complicated formula for that. This might do the trick:
Graphics[Inset[
ImageAdjust[
ImageTake[
Import[FromCharacterCode[
104 + (-1 +
x) (12 + (-2 +
x) (-6 + (-3 + x) (4/
3 + (-4 + x) (1/
8 + (-5 +
x) (-(27/
40) + (-6 + x) (83/
180 + (-7 +
x) (-(299/
1680) + (-8 + x) (671/13440 +
1/310224200866619719680000 (-9 +
x) (-250571425403902786799616000 +
225572976474504083347507200 x -
94279130807229941957510400 x^2 +
24264912267624870901473408 x^3 -
4300646142832260649509936 x^4 +
556011342914624801222512 x^5 -
54170851882847695909848 x^6 +
4050136553216657347576 x^7 -
234304774247637519063 x^8 +
10488890502636982381 x^9 -
360402015263722179 x^10 + 9335087013854129 x^11 -
176454786256101 x^12 + 2298083852807 x^13 -
18440663673 x^14 + 68735987 x^15))))))))) /.
x -> Range[25]]], {900, 2300}, {450, 2800}], {0.4, 1.1,
0.9}], {0, -60}, Center, {Automatic, 80}], Frame -> True,
PlotRange -> {{-70, 70}, {-100, -20}},
FrameTicks -> {None, Automatic}, FrameLabel -> {"", "Energy [MeV]"}]