•πPS

llt = UNMSplit[Lagrangian[ChPT2[4]] /. CouplingConstant[ChPT2[4], 1 | 2 | 3 | 9 | 10 | 11 | 12, ___][___] :> 0, x, DropOrder -> 1, DiagonalToU -> True] ;

llt // Length

5

lltt = (WriteString["stdout", "."] ; ArgumentsSupply[#, x, RenormalizationState[0], ExpansionOrder -> 1, DropOrder -> 1, DiagonalToU -> True]) & /@ llt ;

.....

ArgumentsSupply :: argxpr : Warning : The argument x is already in the expression

ArgumentsSupply :: argxpr : Warning : The argument x is already in the expression

ArgumentsSupply :: argxpr : Warning : The argument x is already in the expression

General :: stop : Further output of ArgumentsSupply :: \" argxpr \" will be suppressed during this calculation.

lll = (WriteString["stdout", "."] ; DiscardTerms[#, Retain -> {Particle[PseudoScalar[0], RenormalizationState[0]] -> 1, Particle[Pion , RenormalizationState[0]] -> 1, Particle[Scalar[2], RenormalizationState[0]] -> 1}, Method -> Expand]) & /@ lltt ;

.....

llle = ExpandU[lll, CommutatorReduce -> True] // Simplify ;

$IsoIndicesCounter = 0 ;

llll = llle // IsoIndicesSupply // SUNReduce // IndicesCleanup // CommutatorReduce // Simplify

1/f _ π^(ó  ) (8 (!, _ 0^( ))^2 (16 L _ 6^( ) p^( )^k1 π^( )^k1 s^( )^0 + 16 L _ 7^( ) p^( )^0 π^( )^k1 s^( )^k1 + i L _ 8^( ) (-8 i p^( )^0 π^( )^k1 s^( )^k1 + f _ (k1 k2 k3)^(2) (p^( )^k3 (2 π^( )^k2 s^( )^k1 + π^( )^k1 s^( )^k2) + p^( )^k2 (π^( )^k3 s^( )^k1 + π^( )^k1 s^( )^k3)) + p^( )^k1 (f _ (k1 k2 k3)^(2) (π^( )^k3 s^( )^k2 + 2 π^( )^k2 s^( )^k3) - 8 i π^( )^k1 s^( )^0))))

fields = {QuantumField[Particle[PseudoScalar[0], RenormalizationState[0]], SUNIndex[I1]][p1], QuantumField[Particle[Pion, RenormalizationState[0]], SUNIndex[I2]][p2], QuantumField[Particle[Scalar[2], RenormalizationState[0]], SUNIndex[I3]][p3]}

{p^( )^I _ 1, π^( )^I _ 2, s^( )^I _ 3}

melsimplified = FeynRule[llll, fields] // Simplify // SUNReduce // IndicesCleanup // CommutatorReduce // Simplify

(64 i (!, _ 0^( ))^2 (2 L _ 6^( ) δ _ (0 I _ 3)^(2) δ _ (I _ 1 I _ 2)^(2) + 2 L _ 7^( ) δ _ (0 I _ 1)^(2) δ _ (I _ 2 I _ 3)^(2) + L _ 8^( ) (δ _ (0 I _ 3)^(2) δ _ (I _ 1 I _ 2)^(2) + δ _ (0 I _ 1)^(2) δ _ (I _ 2 I _ 3)^(2))))/f _ π^(ó  )

Converted by Mathematica  (July 10, 2003)