Excitations in the quantum paramagnetic phase of the quasi-one-dimensional Ising magnet CoNb_2O_6 in a transverse field: Geometric frustration and quantum renormalization effects - Cabrera, I; Thompson, J; Coldea, R; Prabhakaran, D; Bewley, R; Guidi, T; Rodriguez-Rivera, J; Stock, C (Phys. Rev. B, 2014)