Inverse seesaw in supersymmetry

Abstract We study a mechanism where tiny neutrino masses arise only from radiative contribution in a supersymmetric model. Without tuning the Higgs vev or Yukawa coupling, the tree-level light neutrino mass is rotated away by introducing a new singlet neutrino s L that forms a Dirac mass term with the right-handed neutrino n R in each generation. Even with the U ( 1 ) Lep lepton number violation term as non-zero right-handed Majorana neutrino mass M R n R c ¯ n R , the lightest neutrino remains massless at tree level due to an approximate symmetry. Consequently, tiny neutrino masses then only arise from radiative contributions and the right-handed neutrino Majorana mass M R can be at O ( keV ) to give rise to the correct light neutrino mass at O ( eV ) . Supersymmetry ensures that the Majorana neutrino masses M R n R c ¯ n R and M R ⁎ s L c ¯ s L are not generated simultaneously.