====== TTP02-39 The analytic value of a 3-loop sunrise graph in a particular kinematical configuration ====== We consider the scalar integral associated to the 3-loop sunrise graph with a massless line, two massive lines of equal mass $M$, a fourth line of mass equal to $Mx$, and the external invariant timelike and equal to the square of the fourth mass. We write the differential equation in $x$ satisfied by the integral, expand it in the continuous dimension $d$ around $d=4$ and solve the system of the resulting chained differential equations in closed analytic form, expressing the solutions in terms of Harmonic Polylogarithms. As a byproduct, we give the limiting values of the coefficients of the $(d-4)$ expansion at $x=1$ and $x=0$. |**P. Mastrolia, E. Remiddi** | |** Nucl.Phys.B 657 397-406 2003 ** | | {{preprints:2002:ttp02-39.pdf|PDF}} {{preprints:2002:ttp02-39.ps|PostScript}} [[http://arxiv.org/abs/hep-ph/0211451|arXiv]] | | |