L=200;Ω=0.1;σ=0.4;λ=0.01;t[τ_]:=1/aSinh[aτ];x[τ_]:=1/a(Cosh[aτ]-1);Iplus[a_,m_]:=Integrate[Exp[-τ^2/(2σ^2)]Exp[IΩτ+(2IPi)/L(Abs[m]t[τ]-mx[τ])]1/Sqrt[4PiAbs[m]],{τ,-Infinity,Infinity}];Imins[a_,m_]:=Integrate[Exp[-τ^2/(2σ^2)]Exp[-IΩτ+(2IPi)/L(Abs[m]t[τ]-mx[τ])]1/Sqrt[4PiAbs[m]],{τ,-Infinity,Infinity}];η0[a_]:=λSum[Iplus[a,m],{m,-Infinity,-1}]+λSum[Iplus[a,m],{m,1,Infinity}];η1[a_]:=λSum[Imins[a,m],{m,-Infinity,-1}]+λSum[Imins[a,m],{m,1,Infinity}];F[a_]:=-(η0[a]^2/(1+η0[a]^2))+1/(1+η1[a]^2);ListLinePlot[Table[F[a],{a,0.01,1,0.01}],RotateLabelFalse,FrameTrue,FrameStyleDirective[Black,12,Bold],FrameLabel{Style["a",13,Bold,Black],Style["C",13,Bold,Black]},PlotStyle{Block,Thickness[0.015],Blue},DataRange{0,1},PlotRangePadding0,ImageSizeMedium]