How to avoid Wigner bound in a non-perturbative pionless EFT


  Saar Beck  ,  Barnea Nir  
The Racah institute of physics, The Hebrew university of Jerusalem

In pionless EFT the interaction Lagrangian is written as a power expansion of the momentum. As in any quantum field theory, a regularization scheme and a cutoff have to be picked. In pionless EFT there is an inherent problem to combine the two. The effective range of the potential, turn to be nonphysical due to Wigner bound, unless evaluated using perturbation theory. In this talk, we suggest a new philosophy in which pionless EFT can be solved precisely and nonperturbatively. We show that in each increasing order of the pionless EFT the cutoff can grow larger without affecting the effective range and thus we can describe the desired potential more accurately with higher cutoffs. Furthermore, we see that the 3 body force contribution, to prevent Thomas collapse, is suppressed.