  The differential cross sections of the $^{12}$C($^3$He,t)$^{12}$N reaction
leading to formation of the 1$^+$ (ground state), 2$^+$(0.96 MeV), 2$^{-}$(1.19
MeV), and 1$^{-}$(1.80 MeV) states of $^{12}$N are measured at $E$($^3$He)=40
MeV. The analysis of the data is carried out within the modified diffraction
model (MDM) and distorted wave Born approximation (DWBA). Enhanced $rms$ radii
were obtained for the ground, 2$^{-}$(1.19 MeV), and 1$^{-}$(1.80 MeV) states.
We revealed that $^{12}$B, $^{12}$N, and $^{12}$C in the IAS with T=1, and
spin-parities 2$^{-}$ and 1$^{-}$ have increased radii and exhibit properties
of neutron and proton halo states.
