Superconductor order parameter symmetry in UPd2Al3

The heavy fermion compound UPd2Al3 has attracted much interest on account of the coexistence of antiferromagnetism and superconductivity at temperatures below 2 K. The antiferromagnetic fluctuations provide, principally via inelastic neutron scattering, a window on the low frequency dynamics in this material. By an analysis of neutron scattering data, and taking into consideration results from other experimental probes, it is suggested which sheet(s) of the f-electron Fermi surface may play an active role in forming the superconducting state in UPd2Al3. The proposed scheme sheds new light on previously reported anomalies in this material.