Momentum Dependence of the Pion Cloud for Rho Mesons in Nuclear Matter
  We extend hadronic models for rho-meson propagation in cold nuclear matter via coupling to in-medium pions to include finite three-momentum. Special care is taken to preserve gauge invariance. Consequences for photoabsorption on the proton and on nuclei as well as for the dilepton production in relativistic heavy-ion collisions are discussed. 
M. Urban, M. Buballa, R. Rapp and J. Wambach