ODD PARITY AND LINE-NODES IN HEAVY-FERMION SUPERCONDUCTORS

Group theory arguments have demonstrated that a general odd-parity ord er parameter cannot have line nodes in the presence of spin-orbit coup ling. In this paper, it is shown that these arguments do not hold on t he k(z) = pi/c zone face of a hexagonal close-packed lattice. In parti cular, three of the six odd-parity representations vanish identically on this face. This has potential relevance to the heavy fermion superc onductor UPt3.