Lattice calculations for two-component fermion systems with unequal masses: one dimension

Authors : Serdar ELHATISARI

Pages : 631-640

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Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :  We consider systems of two-component fermions with unequal masses and interacting via a short-range attractive potential. We discuss the case where the two-component fermions form a shallow dimer with large scattering length. The three-fermion and four-fermion systems with such properties are universal and characterized by the twofermion scattering length a ff and the ratio of the mass of spin-↑ fermion to the mass of spin-↓ fermion, m ↑ /m ↓ . In this study, using lattice effective field theory, we analyze fermion-dimer and dimer-dimer systems and calculate the universal fermion-dimer and dimer-dimer scattering lengths for various values of the mass ratio m ↑ /m ↓ . We find that these universal scattering lengths increase logarithmically with the mass ratio m ↑ /m ↓ .
Keywords : Lattice effective field theory, scattering phase shifts, universality