In one system, these particles occur as poles of a Green’s function that is proportional to a weight symbolized Z-sub-k. Massless examples of these particles occur as excitations in a class of semimetals exemplified by tantalum arsenide. Interacting examples of these particles form quasiparticles in a model whose 1D case breaks down and is named for Luttinger. The expected occupancy of these particles is given by the function, “one over one plus (15[1])an exponential,” which is bounded between zero and (*) one. Slater determinants are used to encode the anti-symmetry (10[1])property of wavefunctions of these particles. Only one of these particles can occupy a given quantum state at a time due to the Pauli exclusion principle. For 10 points, name these particles with half-integer spins, which are contrasted with bosons. ■END■