Abstract :
The dimensionally regularized massless double box Feynman diagram with powers of propagators equal to one, one leg off the mass shell, i.e. with nonzero q2=p12, and three legs on shell, pi2=0, i=2,3,4, is analytically calculated for general values of q2 and the Mandelstam variables s and t. An explicit result is expressed through (generalized) polylogarithms, up to the fourth order, dependent on rational combinations of q2,s and t, and a one-dimensional integral with a simple integrand consisting of logarithms and dilogarithms.
