Unified ab initio approaches to nuclear structure and reactions

Abstract

The description of nuclei starting from the constituent nucleons and the realistic interactions among them has been a long-standing goal in nuclear physics. In addition to the complex nature of the nuclear forces, with two-, three-and possibly higher many-nucleon components, one faces the quantum-mechanical many-nucleon problem governed by an interplay between bound and continuum states. In recent years, significant progress has been made in ab initio nuclear structure and reaction calculations based on input from QCD-employing Hamiltonians constructed within chiral effective field theory. After a brief overview of the field, we focus on ab initio many-body approaches -built upon the No-Core Shell Model -that are capable of simultaneously describing both bound and scattering nuclear states, and present results for resonances in light nuclei, reactions important for astrophysics and fusion research. In particular, we review recent calculations of resonances in the 6 He halo nucleus, of five-and six-nucleon scattering, and an investigation of the role of chiral threenucleon interactions in the structure of 9 Be. Further, we discuss applications to the 7 Be(p, γ) 8 B radiative capture. Finally, we highlight our efforts to describe transfer reactions including the 3 H(d, n) 4 He fusion.

Microscopic optical potentials for calcium isotopes

“…On the other hand, the ab-initio nuclear reaction community is behind in reached mass number, precision, and accuracy. There has been a lot of effort in developing microscopic reaction theories for light nuclei starting from realistic N N and 3NFs [20][21][22][23][24][25][26][27][28][29][30], while less so for medium-mass and heavy nuclei [31][32][33][34][35]. With upcoming experiments on rare isotopes in the mediumand heavy-mass region of the nuclear chart, it is important to develop ab-initio reaction theory that can make accurate predictions in these mass regions.…”

Microscopic optical potential for exotic isotopes from chiral effective field theory

“…Microscopic many-body methods [9][10][11] with chiral two-and three-body forces have been successful in describing the bound-state properties of neutron-rich matter. Complementary and consistent nuclear reaction models are under development [12][13][14], and of these, global optical potentials aim to address the broadest theory needs for interpreting RIB scattering experiments and simulating r-process nucleosynthesis. In fact, current modeling of the strong r-process favors a cold scenario in binary neutron star mergers [6][7][8][15][16][17], where mass transfer to highly neutron-rich isotopes occurs and freeze-out is achieved more rapidly, which enhances the importance of radiative neutron capture processes in determining the final abundance pattern of rprocess elements [18].…”