Direct radiative capture of neutron in drip-line nuclei

The analytic expressions of radial matrix elements <l(c) = 0\r\l(h) = 1>, <l(c) = 1\r\l(h) = 0> and <l(c) = 1\r\l(h) = 2> in a finite square-well potential are derived. Based on these analytic expressions of radial matrix elements, the neutron direct radiative capture (DRC) processes leading to bound p-orbit from incident s-wave, and leading to s- and d-orbits from incident p-wave are discussed. For the DRC processes leading to loosely bound orbits, the dominant contributions to the radial matrix elements come from the outer region of nuclear potential radius R.