Low-momentum interactions with smooth cutoffs

S. K. Bogner; R. J. Furnstahl; S. Ramanan; A. Schwenk

doi:10.1016/j.nuclphysa.2006.11.123

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Low-momentum interactions with smooth cutoffs

S. K. Bogner·R. J. Furnstahl·S. Ramanan·A. Schwenk

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Abstract

Nucleon-nucleon potentials evolved to low momentum, which show great promise in few- and many-body calculations, have generally been formulated with a sharp cutoff on relative momenta. However, a sharp cutoff has technical disadvantages and can cause convergence problems at the 10-100 keV level in the deuteron and triton. This motivates using smooth momentum-space regulators as an alternative. We generate low-momentum interactions with smooth cutoffs both through energy-independent renormalization group methods and using a multi-step process based on the Bloch-Horowitz approach. We find greatly improved convergence for calculations of the deuteron and triton binding energies in a harmonic oscillator basis compared to results with a sharp cutoff. Even a slight evolution of chiral effective field theory interactions to lower momenta is beneficial. The renormalization group preserves the long-range part of the interaction, and consequently the renormalization of long-range operators, such as the quadrupole moment, the radius and 1/r, is small. This demonstrates that low-energy observables in the deuteron are reproduced without short-range correlations in the wave function.

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S. K. Bogner, R. J. Furnstahl, S. Ramanan, A. Schwenk. 2006-09-01. Low-momentum interactions with smooth cutoffs. https://doi.org/10.1016/j.nuclphysa.2006.11.123

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