Nucleon–nucleon resonances at intermediate energies using a complex energy formalism

Abstract

We apply our method of complex scaling, valid for a general class of potentials, in a search for nucleonnucleon S-matrix poles up to 2 GeV laboratory kinetic energy. We find that the realistic potentials JISP16, constructed from inverse scattering, and chiral field theory potentials N 3 LO and N 2 LO opt support resonances in energy regions well above their fit regions. In some cases these resonances have widths that are small when compared with the real part of the S-matrix pole.

Calculation of Expectation Values of Operators in the Complex Scaling Method

“…This behavior of the complex scaled HO basis functions was the reason in [58] the authors worked in momentum space and adopted the contour deformation method for solving a complex momentum T-matrix equation. We also note that in a recent work of the CSM with realistic potentials [37,38] the backrotation of HO basis functions did not cause any problem since, due to the short range nature of the nucleon-nucleon force, the complex scaled matrix elements were all converged.…”

“…The work was originated by Nuttall and Cohen [30], as a way of solving the purely scattering many-body problem for energies above the break-up threshold to obtain scattering amplitudes without imposing many-body scattering boundary conditions. It was shown to be successful for both short range and long range potentials [31][32][33], for mean field calculations [34], for scattering calculations above the four body break-up threshold [35] and recently also facilitated modern nuclear forces [36][37][38]. This complex energy formalism appears with different names and flavors in bibliography such as complex-coordinate method [30,39] or complex scaled Lippmann-Schwinger (CSLS) method [32,33].…”

Evidence for excitation of two resonance states in the isovector two-baryon system with a mass of 2.2 GeV/c2

“…The 3 P 0 s(0 − ) resonance has not been observed earlier: the relevant transition is forbidden in reaction (1) and the pp → pp database is most likely not sensitive enough to this resonance because of its small branching ratio into the elastic channel. However, a recent analysis [44] of several realistic NN interactions has indicated possible existence of the 3 P 0 resonance alongside with the known 1 D 2 , 3 F 3 , and 3 P 2 resonances.…”

Nonempirical Interactions for the Nuclear Shell Model: An Update

“…Of course, this will be especially relevant as we seek to understand the structure for increasingly neutron-rich nuclei. While a variety of approaches for coupling the shell model and other many-body methods to the continuum exist (see, e.g., (275)(276)(277), as well as the reviews (278,279)), methods based on the Berggren basis (280) appear to be most suitable in the context of VS-IMSRG and SMCC.…”