High frequency study of the orbital ordering resonance in the strongly   correlated heavy fermion metal CeB6
  We report results of the study of the recently discovered magnetic resonance in the orbitally ordered phase of CeB6 (the orbital ordering resonance) in a wide frequency range 44-360 GHz. It is found that the g-factor for this resonance increases with frequency from g(44 GHz)~1.55 to g(>250 GHz)~1.7. In addition to the orbital ordering resonance for the frequencies exceeding 200 GHz a new magnetic resonance with the g-factor 1.2-1.3 is detected. 
S.V. Demishev, A.V. Semeno, H. Ohta, S. Okubo, Yu.B. Paderno, N.Yu.   Shitsevalova, N.E. Sluchanko