Find here the mathematica file
FormFactors.m containing the functions

P2[\Delta,{a1,a2},{\th1,\th2}]
Q3[\Delta,{a1,a2,a3},{\th1,\th2,\th3}]
Q4[\Delta,{a1,a2,a3,a4},{\th1,\th2,\th3,\th4}]

appearing (with an obvious change of notations) in Eqs. (21), (33) of the paper hep-th/0507133 . Here \Delta equals 1/2 for the energy operator \varepsilon and 1/16 for the spin operator \sigma.
The file contains the functions corresponding to the following choices of the indeces {a1,.....,an}:

2 particles: 11,12,13,14,15,16,17,18,22,23,24,25,26,27,33,34,35,36,44,45
3 particles: 111,112,113,114,115,123,125
4 particles: 1111