Universal trimers with p-wave interactions and the faux-Efimov effect

An unusual class of p-wave universal trimers with symmetry LΠ=1± is identified, for both a two-component fermionic trimer with s- and p-wave scattering length close to unitarity and for a one-component fermionic trimer at p-wave unitarity. Moreover, fermionic trimers made of atoms with two internal spin components are found for LΠ=1±, when the p-wave interaction between spin-up and spin-down fermions is close to unitarity and/or when the interaction between two spin-up fermions is close to the p-wave unitary limit. The universality of these p-wave universal trimers is tested here by considering van der Waals interactions in a Lennard-Jones potential with different numbers of two-body bound states; our calculations also determine the value of the scattering volume or length where the trimer state hits zero energy and can be observed as a recombination resonance. The faux-Efimov effect appears with trimer symmetry LΠ=1⁻ when the two fermion interactions are close to p-wave unitarity and the lowest 1/R² coefficient gets modified, thereby altering the usual Wigner threshold law for inelastic processes involving 3-body continuum channels.