Added/improved some of the examples.

Examples/BChPT/OneLoop/N-N.m

@@ -0,0 +1,74 @@
+(* ::Package:: *)
+
+(* :Title: N-N															*)
+
+(*
+	This software is covered by the GNU General Public License 3.
+	Copyright (C) 2014-2020 Vladyslav Shtabovenko
+*)
+
+(* :Summary:  N -> N, BChPT, master integrals, 1-loop					*)
+
+(* ------------------------------------------------------------------------ *)
+
+
+
+(* ::Title:: *)
+(*One loop correction to the nucleon mass*)
+
+
+(* ::Section:: *)
+(*Load FeynCalc and the necessary add-ons or other packages*)
+
+
+description="N -> N, BChPT, master integrals, 1-loop";
+If[ $FrontEnd === Null,
+	$FeynCalcStartupMessages = False;
+	Print[description];
+];
+If[ $Notebooks === False,
+	$FeynCalcStartupMessages = False
+];
+<<FeynCalc`
+
+FCCheckVersion[9,3,0];
+
+
+(* ::Section:: *)
+(*Enter the amplitude*)
+
+
+(* ::Text:: *)
+(*The 1/(2Pi)^D prefactor is implicit. We enter Eq. 5.182 from hep-ph/0210398*)
+
+
+amp[0] = (-(-1/2 GA[5].(GAD[\[Mu]].GSD[v]-FVD[v,\[Mu]]).CSI[i]FVD[k,\[Mu]])).
+(-1/2 GA[5].(GAD[\[Nu]].GSD[v]-FVD[v,\[Nu]]).CSI[i])FVD[k,\[Nu]]*
+SFAD[{{0,v.(r-k)}},{k,M^2}]
+
+
+(* ::Section:: *)
+(*Calculate the amplitude*)
+
+
+(* ::Text:: *)
+(*Simplify the Pauli algebra and carry out tensor reduction*)
+
+
+amp[1] = amp[0]//PauliSimplify//FCMultiLoopTID[#,{k}]&
+
+
+(* ::Section:: *)
+(*Check the final results*)
+
+
+knownResult = 3/4 SFAD[{{k,0},{M^2,1},1}]*
+SPD[r,v]-3/4 SFAD[{{k,0},{M^2,1},1},{{0,(-k+r).v},{0,1},1}]*
+ (SPD[r,v]^2-M^2 SPD[v,v]);
+FCCompareResults[amp[1],knownResult,
+Text->{"\tCompare to hep-ph/0210398, Eq 5.183:",
+"CORRECT.","WRONG!"}, Interrupt->{Hold[Quit[1]],Automatic}];
+Print["\tCPU Time used: ", Round[N[TimeUsed[],4],0.001], " s."];
+
+
+