%% Gives back beta-functions and anomalous dimensions, %% given combinatorial factors S, a1, and a2. function [betags,gamma_phi,gamma_phi2]=betas_gammas(d,gs,S,a1,a2) %% Common factors I2=0; for X1=1:2 for X2=1:2 I2=I2+S(X1,X2)*gs(X1)*gs(X2); end end I4=0; for X1=1:2 for X2=1:2 for X3=1:2 for X4=1:2 for X5=1:2 I4=I4+S(X1,X5)*a1(X5,X2,X3,X4)*gs(X1)*gs(X2)*gs(X3)*gs(X4); end end end end end I3=zeros(2,1); for X=1:2 for X1=1:2 for X2=1:2 for X3=1:2 I3(X)=I3(X)+a1(X,X1,X2,X3)*gs(X1)*gs(X2)*gs(X3); end end end end I5A=zeros(2,1); for X=1:2 for X1=1:2 for X2=1:2 for X3=1:2 for X4=1:2 for X5=1:2 I5A(X)=I5A(X)+a2(X,X1,X2,X3,X4,X5)*gs(X1)*gs(X2)*gs(X3)*gs(X4)*gs(X5); end end end end end end I5B=zeros(2,1); for X=1:2 for X1=1:2 for X2=1:2 for X3=1:2 I5B(X)=I5B(X)+a1(X,X1,X2,X3)*gs(X1)*gs(X2)*I3(X3); end end end end %% Anomalous dimensions and beta functions % gamma_phi gamma_phi=(1/6)*I2-(11/216)*(I2^2)+(1/9)*I4; % gamma_phi2 gamma_phi2=I2-(1/24)*(I2^2)+I4; % Beta functions eta=gamma_phi; betags=-I3+(7/24)*I2*I3-(1/2)*I5A-(3/4)*I5B; betags=betags+((-6+d+3*eta)/2)*gs; end