Sharp cut-off approximation for neutron emission in halo 11Be fusion with 12C

In 1997 R. Bhattacharya and K. Krishan calculated the r.m.s. radius for the neutron halo as being RH = 3.67 fm. They could reproduce 11Be experimental energy level scheme and spectroscopic factors obtained in (d,p) reaction by using a coupling particle-vibration model. Their calculated value is slightly higher than the experimental value of 3.38 ± 0.06 fm reported by E. Liatard. We relied on this value for the neutron r.m.s. of 3.38 ± 0.06 fm when we applied the sharp cut-off approach of neutron emission for the fusion of 11Be halo nucleus with 12C target. For 11.25 A MeV beam energy, lgrazing = 26 ℎ and l critical = 8 ℎ. The probability Pm(l) for neutron emission have been determined for each l between 0 and lcritical by means of a graphical method. We calculated the emission probability for the halo neutron for two more neutron r.m.s. radius: 3.2 fm and 3.3 fm. The nucleus radii are calculated as R = r0 · A1/3, where r0 has three values. The halo neutron emission probabilities (P.P.) for three radii for 11Be + 12C at 11.25 AMeV beam energy are presented: P.P.(1) represents the halo neutron emission probability for r0=1.26 fm for both the target and the projectile; P.P.(2) represents the halo neutron emission probability for r0=1.36 fm for the target and r0=1.26 for the projectile; P.P.(3) represents the halo neutron emission probability for r0=1.36 for both the target and the projectile. If r0 increases the emission probability decreases if RH constant. The halo neutron emission probability dependence on the angular momentum l, in the case of 11Be+12C, is presented for RH=3.20 fm, RH=3.30 fm and RH=3.38 fm. Fusion studies involving halo nuclei and light targets could be an alternative way for the halo neutron r.m.s. radius determination. (authors)