Three loop form factors of a massive spin-2 particle with nonuniversal coupling

Nine-Propagator Master Integrals for Massless Three-Loop Form Factors

We complete the calculation of master integrals for massless three-loop form factors by computing the previously-unknown three diagrams with nine propagators in dimensional regularisation. Each of the integrals yields a six-fold Mellin-Barnes representation which we use to compute the coefficients of the Laurent expansion in ǫ. Using Riemann ζ functions of up to weight six, we give fully analyt...

Master Integrals for Massless Three-Loop Form Factors: One-Loop and Two-Loop Insertions

The three-loop form factors in massless QCD can be expressed as a linear combination of master integrals. Besides a number of master integrals which factorise into products of one-loop and two-loop integrals, one finds 16 genuine three-loop integrals. Of these, six have the form of a bubble insertion inside a one-loop or two-loop vertex integral. We compute all master integrals with these inser...

Metric modifications for a massive spin 1 particle

Massive Spin 3 / 2 Electrodynamics

We study the general non-minimally coupled charged massive spin 3/2 model both for its low energy phenomenological properties and for its unitarity, causality and degrees of freedom behaviour. When the model is viewed as an effective theory, its parameters (after ensuring the correct excitation count) are related to physical characteristics, such as the magnetic moment g factor, by means of low...

Two - loop sunset diagrams with three massive lines

In this paper, we consider the two-loop sunset diagram with two different masses, m and M , at spacelike virtuality q2 = −m2. We find explicit representations for the master integrals and an analytic result through O(ε) in d = 4 − 2ε space-time dimensions for the case of equal masses, m = M . PACS: 11.15.-q, 12.38.Bx