Header update - two possibilities: analytical and RT solution

include/partons/modules/gpd/pionGPD/algebraicToyModel.h

@@ -73,6 +73,7 @@ protected:
 private:
 
     double c;                                   // t-dependece of the GPD model.
+    double c1;                                  // t-depence x=1 limit ERBL region (Analytical expressions)
     double cM;                                  // Auxilary t-dependece for the computation of the singlet distribution.
     double m2;                                  // Squared pion mass scale.
     double ca;                                  // Auxiliary t-dependence parameter for computing the inverse Radon transform.
@@ -81,6 +82,11 @@ private:
     double alpha;                               // Kinematic variable for D-terms: \alpha = m_x/m_xi
     double dplus;                               // D-term analytical computation
     double dminus;                              // D-term analytical computation
+
+    double alpha1;                              // Kinematic variable for D-terms: \alpha = m_x/m_xi (Analytical expressions)
+    double dplus1;                              // D-term analytical computation (Analytical expressions)
+    double dminus1;                             // D-term analytical computation (Analytical expressions)
+
     double m2D;                                 // D-term t-dependence (mass-scale). Fitting of Phys. Rev. D 97, 014020 (2018) gravitational FFs.
 
     // TODO: Explore the possibility of storing DDs into a map: ( double t-value, std::vector<double> DDt-value ). So at the level of evaluation on just needs to check that map.