Five-body calculation of s-wave n-4He scattering at next-to-leading order pionless effective field theory

Abstract

We present the first five-body calculations of s-wave n-4He scattering within leading order and next-to-leading order (NLO) pionless effective field theory (π̸EFT). Using an harmonic oscillator trap technique and π̸EFT fitted to just six well-established experimental parameters, we predict the s-wave n-4He phase shifts, scattering length an4He1/2(NLO)=2.47(4num.)(17theor.)fm, and effective range rn4He1/2(NLO)=1.384(3num.)(211theor.)fm in agreement with experiment. The apparent cutoff independence of our results is used to estimate the theoretical errors coming as an integral part of our final results.