Effective range corrections from effective field theory with di-baryon fields and perturbative pions

الأصل · EN

Contributions of perturbative pions around a non-trivial fixed point are studied by utilizing di-baryon fields. We calculate ¹S₀ and ³S₁ phase shifts for the np scattering at low energies up to one-pion-exchange contributions. We also calculate effective range parameters, v₂, v₃ and v₄ in the higher order of the effective range expansion, and obtain corrections of the effective range to the expressions previously reported by Cohen and Hansen. After the scattering length and the effective range are renormalized, we study the role of renormailzation scale parameter μ and discuss the range of validity of the theory.