Resonant breakup ofC19on a proton target

Abstract

The resonant breakup of 19 C on a proton target at 70 MeV/nucleon is analyzed using Faddeev-Alt, Grassberger, Sandhas (Faddeev-AGS) and continuum-discretized coupled-channels (CDCC) reaction frameworks, where in both cases a three-body model ( 18 C + n + p) for the reaction is considered. Taking a 18 C + p potential from a global nucleon-nucleus parametrization and a L-independent Gaussian proton-neutron potential, both methods provide very similar results for the calculated observables. However, when this simplified proton-neutron potential is replaced by the more realistic CD-Bonn potential, the breakup cross section, calculated with the Faddeev AGS formalism, decreases by almost one order of magnitude, largely underestimating the experimental data. From this calculation, we conclude that, within a core + valence neutron model, the single-particle mechanism gives a negligible contribution to the calculated resonant breakup and therefore core-excitation mechanisms should be taken into account.

Erratum: Investigation of the3/22−state ofLi9with microscopic structure and

“…In the most recent report [38], the electric quadrupole transition strength is observed as B(E2; 1/2 4 . In this work, the transition strength is obtained as B(E2) = 8.778 e 2 fm 4 .…”

“…In addition, Moro and his collaborators have shown such important role of the core excitation effect of the 11 Be nucleus in the inelastic and breakup cross sections [4][5][6]. Both of the 8 B and 11 Be nuclei have "a valence nucleon + core nucleus" structure (p + 7 Be and n + 10 Be structure for 8 B and 11 Be, respectively).…”

Three-body model for the analysis of quasifree scattering reactions in inverse kinematics

“…with μ i (μ j ) the reduced mass of the initial (final) mass partition and T 3b i,f (α) the transition amplitude obtained by replacing the CDCC expansion (12) in the transition amplitude (9). The sum in σ includes the spin projections of the outgoing pN pair and of the residual nucleus C. The angle specified by c is the scattering angle of the core in the c.m.…”

“…Although both kinds of experiments are meant to provide similar information, there are important differences between them. In knockout reactions, a nucleon is suddenly removed from the fast-moving projectile after colliding with a light target nucleus, like 9 Be. Owing to the strongly absorptive nature of the core-target interaction at these energies, the process is highly peripheral and hence mainly dependent on the tail of the wave function of the removed nucleon or, more correctly, on the overlap function between the projectile and residual core wave functions.…”

“…If reliable structure information is to be extracted from these experiments, these approximations need to be revisited and tested. Consequently, the validity of the DWIA formalism should be investigated comparing with more elaborate reaction theories [8][9][10].…”