  The case of a Feshbach shape resonance in the pairing mechanism for high T c
superconductivity in a crystalline lattice of doped metallic nanotubes is
described. The superlattice of doped metallic nanotubes provides a
superconductor with a strongly asymmetric gap. The disparity and different
spatial locations of the wave functions of electrons in different subbands at
the Fermi level should suppress the single electron impurity interband
scattering giving multiband superconductivity in the clean limit. The Feshbach
resonances will arise from the component single-particle wave functions out of
which the electron pair wave function is constructed: pairs of wave functions
which are time inverse of each other. The Feshbach shape resonance increases
the critical temperature by tuning the chemical potential at the Lifshitz
electronic topological transition (ETT) where the Fermi surface of one of the
bands changes from the one dimensional (1D) to the two dimensional (2D)
topology (1D/2D ETT).
