Quasi-elastic barrier distribution for the 7Li+144Sm weakly bound system

D.R. OTOMAR; P.R.S. GOMES; J. LUBIAN; D.S. MONTEIRO; O.A. CAPURRO; G.V. MARTÍ; A.J. PACHECO; J.O. FERNÁNDEZ NIELLO; A. ARAZI; A. NEGRI; J.M. FIGUEIRA

São Sebastião, Brasil

Workshop; XXXI Reunião de Trabalho sobre Física Nuclear no Brasil; 2008

sociedade Brasileira de Física

We have measured the excitation functions of quasielastic and elastic scattering, at backward angles for a range of energies from well below to above the barrier, for the 7Li + 144Sm system. Moreover, barrier distributions were extracted from these measured excitation functions by a numerical method, using the ¯rst derivative of the excitation function. The analysis of the data was performed by using the code FRESCO, and the S~ao Paulo potential as a parameter free bare potential. From the analysis one concluded that the quadrupole and octupole excitations of 144Sm and the one-neutron transfer channel are important reaction processes. As we did not change any parameter of the bare potential, no attempt was made to ¯t the data, but rather to compare the experimental excitation function and the corresponding barrier distribution with theoretical predictions, using a coupling scheme that takes into account the above mentioned inelastic and transfer channels. This comparison for the excitation function gives reasonable good agreement, except at the highest energies, whereas for the barrier distribution one can notice more clearly that even at the barrier energy there is some disagreement between theoretical predictions and experimental results. This disagreement is not unexpected, since as the 7Li is a weakly bound projectile, the breakup channel should also be included in the coupling scheme. In order to verify the in°uence of the break up channel in the quasi-elastic process, at the present we are performing calculations using the CDCC method, since the break up process feeds states in the continuum. In our calculations we assume that 7Li breaks up in two fragments: tritium and alpha particles. We plan to have the results of the CDCC calculations when this contribution is presented. of energies from well below to above the barrier, for the 7Li + 144Sm system. Moreover, barrier distributions were extracted from these measured excitation functions by a numerical method, using the ¯rst derivative of the excitation function. The analysis of the data was performed by using the code FRESCO, and the S~ao Paulo potential as a parameter free bare potential. From the analysis one concluded that the quadrupole and octupole excitations of 144Sm and the one-neutron transfer channel are important reaction processes. As we did not change any parameter of the bare potential, no attempt was made to ¯t the data, but rather to compare the experimental excitation function and the corresponding barrier distribution with theoretical predictions, using a coupling scheme that takes into account the above mentioned inelastic and transfer channels. This comparison for the excitation function gives reasonable good agreement, except at the highest energies, whereas for the barrier distribution one can notice more clearly that even at the barrier energy there is some disagreement between theoretical predictions and experimental results. This disagreement is not unexpected, since as the 7Li is a weakly bound projectile, the breakup channel should also be included in the coupling scheme. In order to verify the in°uence of the break up channel in the quasi-elastic process, at the present we are performing calculations using the CDCC method, since the break up process feeds states in the continuum. In our calculations we assume that 7Li breaks up in two fragments: tritium and alpha particles. We plan to have the results of the CDCC calculations when this contribution is presented. of energies from well below to above the barrier, for the 7Li + 144Sm system. Moreover, barrier distributions were extracted from these measured excitation functions by a numerical method, using the ¯rst derivative of the excitation function. The analysis of the data was performed by using the code FRESCO, and the S~ao Paulo potential as a parameter free bare potential. From the analysis one concluded that the quadrupole and octupole excitations of 144Sm and the one-neutron transfer channel are important reaction processes. As we did not change any parameter of the bare potential, no attempt was made to ¯t the data, but rather to compare the experimental excitation function and the corresponding barrier distribution with theoretical predictions, using a coupling scheme that takes into account the above mentioned inelastic and transfer channels. This comparison for the excitation function gives reasonable good agreement, except at the highest energies, whereas for the barrier distribution one can notice more clearly that even at the barrier energy there is some disagreement between theoretical predictions and experimental results. This disagreement is not unexpected, since as the 7Li is a weakly bound projectile, the breakup channel should also be included in the coupling scheme. In order to verify the in°uence of the break up channel in the quasi-elastic process, at the present we are performing calculations using the CDCC method, since the break up process feeds states in the continuum. In our calculations we assume that 7Li breaks up in two fragments: tritium and alpha particles. We plan to have the results of the CDCC calculations when this contribution is presented. of energies from well below to above the barrier, for the 7Li + 144Sm system. Moreover, barrier distributions were extracted from these measured excitation functions by a numerical method, using the ¯rst derivative of the excitation function. The analysis of the data was performed by using the code FRESCO, and the S~ao Paulo potential as a parameter free bare potential. From the analysis one concluded that the quadrupole and octupole excitations of 144Sm and the one-neutron transfer channel are important reaction processes. As we did not change any parameter of the bare potential, no attempt was made to ¯t the data, but rather to compare the experimental excitation function and the corresponding barrier distribution with theoretical predictions, using a coupling scheme that takes into account the above mentioned inelastic and transfer channels. This comparison for the excitation function gives reasonable good agreement, except at the highest energies, whereas for the barrier distribution one can notice more clearly that even at the barrier energy there is some disagreement between theoretical predictions and experimental results. This disagreement is not unexpected, since as the 7Li is a weakly bound projectile, the breakup channel should also be included in the coupling scheme. In order to verify the in°uence of the break up channel in the quasi-elastic process, at the present we are performing calculations using the CDCC method, since the break up process feeds states in the continuum. In our calculations we assume that 7Li breaks up in two fragments: tritium and alpha particles. We plan to have the results of the CDCC calculations when this contribution is presented. of energies from well below to above the barrier, for the 7Li + 144Sm system. Moreover, barrier distributions were extracted from these measured excitation functions by a numerical method, using the ¯rst derivative of the excitation function. The analysis of the data was performed by using the code FRESCO, and the S~ao Paulo potential as a parameter free bare potential. From the analysis one concluded that the quadrupole and octupole excitations of 144Sm and the one-neutron transfer channel are important reaction processes. As we did not change any parameter of the bare potential, no attempt was made to ¯t the data, but rather to compare the experimental excitation function and the corresponding barrier distribution with theoretical predictions, using a coupling scheme that takes into account the above mentioned inelastic and transfer channels. This comparison for the excitation function gives reasonable good agreement, except at the highest energies, whereas for the barrier distribution one can notice more clearly that even at the barrier energy there is some disagreement between theoretical predictions and experimental results. This disagreement is not unexpected, since as the 7Li is a weakly bound projectile, the breakup channel should also be included in the coupling scheme. In order to verify the in°uence of the break up channel in the quasi-elastic process, at the present we are performing calculations using the CDCC method, since the break up process feeds states in the continuum. In our calculations we assume that 7Li breaks up in two fragments: tritium and alpha particles. We plan to have the results of the CDCC calculations when this contribution is presented. of energies from well below to above the barrier, for the 7Li + 144Sm system. Moreover, barrier distributions were extracted from these measured excitation functions by a numerical method, using the ¯rst derivative of the excitation function. The analysis of the data was performed by using the code FRESCO, and the S~ao Paulo potential as a parameter free bare potential. From the analysis one concluded that the quadrupole and octupole excitations of 144Sm and the one-neutron transfer channel are important reaction processes. As we did not change any parameter of the bare potential, no attempt was made to ¯t the data, but rather to compare the experimental excitation function and the corresponding barrier distribution with theoretical predictions, using a coupling scheme that takes into account the above mentioned inelastic and transfer channels. This comparison for the excitation function gives reasonable good agreement, except at the highest energies, whereas for the barrier distribution one can notice more clearly that even at the barrier energy there is some disagreement between theoretical predictions and experimental results. This disagreement is not unexpected, since as the 7Li is a weakly bound projectile, the breakup channel should also be included in the coupling scheme. In order to verify the in°uence of the break up channel in the quasi-elastic process, at the present we are performing calculations using the CDCC method, since the break up process feeds states in the continuum. In our calculations we assume that 7Li breaks up in two fragments: tritium and alpha particles. We plan to have the results of the CDCC calculations when this contribution is presented. of energies from well below to above the barrier, for the 7Li + 144Sm system. Moreover, barrier distributions were extracted from these measured excitation functions by a numerical method, using the ¯rst derivative of the excitation function. The analysis of the data was performed by using the code FRESCO, and the S~ao Paulo potential as a parameter free bare potential. From the analysis one concluded that the quadrupole and octupole excitations of 144Sm and the one-neutron transfer channel are important reaction processes. As we did not change any parameter of the bare potential, no attempt was made to ¯t the data, but rather to compare the experimental excitation function and the corresponding barrier distribution with theoretical predictions, using a coupling scheme that takes into account the above mentioned inelastic and transfer channels. This comparison for the excitation function gives reasonable good agreement, except at the highest energies, whereas for the barrier distribution one can notice more clearly that even at the barrier energy there is some disagreement between theoretical predictions and experimental results. This disagreement is not unexpected, since as the 7Li is a weakly bound projectile, the breakup channel should also be included in the coupling scheme. In order to verify the in°uence of the break up channel in the quasi-elastic process, at the present we are performing calculations using the CDCC method, since the break up process feeds states in the continuum. In our calculations we assume that 7Li breaks up in two fragments: tritium and alpha particles. We plan to have the results of the CDCC calculations when this contribution is presented. of energies from well below to above the barrier, for the 7Li + 144Sm system. Moreover, barrier distributions were extracted from these measured excitation functions by a numerical method, using the ¯rst derivative of the excitation function. The analysis of the data was performed by using the code FRESCO, and the S~ao Paulo potential as a parameter free bare potential. From the analysis one concluded that the quadrupole and octupole excitations of 144Sm and the one-neutron transfer channel are important reaction processes. As we did not change any parameter of the bare potential, no attempt was made to ¯t the data, but rather to compare the experimental excitation function and the corresponding barrier distribution with theoretical predictions, using a coupling scheme that takes into account the above mentioned inelastic and transfer channels. This comparison for the excitation function gives reasonable good agreement, except at the highest energies, whereas for the barrier distribution one can notice more clearly that even at the barrier energy there is some disagreement between theoretical predictions and experimental results. This disagreement is not unexpected, since as the 7Li is a weakly bound projectile, the breakup channel should also be included in the coupling scheme. In order to verify the in°uence of the break up channel in the quasi-elastic process, at the present we are performing calculations using the CDCC method, since the break up process feeds states in the continuum. In our calculations we assume that 7Li breaks up in two fragments: tritium and alpha particles. We plan to have the results of the CDCC calculations when this contribution is presented. of energies from well below to above the barrier, for the 7Li + 144Sm system. Moreover, barrier distributions were extracted from these measured excitation functions by a numerical method, using the ¯rst derivative of the excitation function. The analysis of the data was performed by using the code FRESCO, and the S~ao Paulo potential as a parameter free bare potential. From the analysis one concluded that the quadrupole and octupole excitations of 144Sm and the one-neutron transfer channel are important reaction processes. As we did not change any parameter of the bare potential, no attempt was made to ¯t the data, but rather to compare the experimental excitation function and the corresponding barrier distribution with theoretical predictions, using a coupling scheme that takes into account the above mentioned inelastic and transfer channels. This comparison for the excitation function gives reasonable good agreement, except at the highest energies, whereas for the barrier distribution one can notice more clearly that even at the barrier energy there is some disagreement between theoretical predictions and experimental results. This disagreement is not unexpected, since as the 7Li is a weakly bound projectile, the breakup channel should also be included in the coupling scheme. In order to verify the in°uence of the break up channel in the quasi-elastic process, at the present we are performing calculations using the CDCC method, since the break up process feeds states in the continuum. In our calculations we assume that 7Li breaks up in two fragments: tritium and alpha particles. We plan to have the results of the CDCC calculations when this contribution is presented. of energies from well below to above the barrier, for the 7Li + 144Sm system. Moreover, barrier distributions were extracted from these measured excitation functions by a numerical method, using the ¯rst derivative of the excitation function. The analysis of the data was performed by using the code FRESCO, and the S~ao Paulo potential as a parameter free bare potential. From the analysis one concluded that the quadrupole and octupole excitations of 144Sm and the one-neutron transfer channel are important reaction processes. As we did not change any parameter of the bare potential, no attempt was made to ¯t the data, but rather to compare the experimental excitation function and the corresponding barrier distribution with theoretical predictions, using a coupling scheme that takes into account the above mentioned inelastic and transfer channels. This comparison for the excitation function gives reasonable good agreement, except at the highest energies, whereas for the barrier distribution one can notice more clearly that even at the barrier energy there is some disagreement between theoretical predictions and experimental results. This disagreement is not unexpected, since as the 7Li is a weakly bound projectile, the breakup channel should also be included in the coupling scheme. In order to verify the in°uence of the break up channel in the quasi-elastic process, at the present we are performing calculations using the CDCC method, since the break up process feeds states in the continuum. In our calculations we assume that 7Li breaks up in two fragments: tritium and alpha particles. We plan to have the results of the CDCC calculations when this contribution is presented. of energies from well below to above the barrier, for the 7Li + 144Sm system. Moreover, barrier distributions were extracted from these measured excitation functions by a numerical method, using the ¯rst derivative of the excitation function. The analysis of the data was performed by using the code FRESCO, and the S~ao Paulo potential as a parameter free bare potential. From the analysis one concluded that the quadrupole and octupole excitations of 144Sm and the one-neutron transfer channel are important reaction processes. As we did not change any parameter of the bare potential, no attempt was made to ¯t the data, but rather to compare the experimental excitation function and the corresponding barrier distribution with theoretical predictions, using a coupling scheme that takes into account the above mentioned inelastic and transfer channels. This comparison for the excitation function gives reasonable good agreement, except at the highest energies, whereas for the barrier distribution one can notice more clearly that even at the barrier energy there is some disagreement between theoretical predictions and experimental results. This disagreement is not unexpected, since as the 7Li is a weakly bound projectile, the breakup channel should also be included in the coupling scheme. In order to verify the in°uence of the break up channel in the quasi-elastic process, at the present we are performing calculations using the CDCC method, since the break up process feeds states in the continuum. In our calculations we assume that 7Li breaks up in two fragments: tritium and alpha particles. We plan to have the results of the CDCC calculations when this contribution is presented. of energies from well below to above the barrier, for the 7Li + 144Sm system. Moreover, barrier distributions were extracted from these measured excitation functions by a numerical method, using the ¯rst derivative of the excitation function. The analysis of the data was performed by using the code FRESCO, and the S~ao Paulo potential as a parameter free bare potential. From the analysis one concluded that the quadrupole and octupole excitations of 144Sm and the one-neutron transfer channel are important reaction processes. As we did not change any parameter of the bare potential, no attempt was made to ¯t the data, but rather to compare the experimental excitation function and the corresponding barrier distribution with theoretical predictions, using a coupling scheme that takes into account the above mentioned inelastic and transfer channels. This comparison for the excitation function gives reasonable good agreement, except at the highest energies, whereas for the barrier distribution one can notice more clearly that even at the barrier energy there is some disagreement between theoretical predictions and experimental results. This disagreement is not unexpected, since as the 7Li is a weakly bound projectile, the breakup channel should also be included in the coupling scheme. In order to verify the in°uence of the break up channel in the quasi-elastic process, at the present we are performing calculations using the CDCC method, since the break up process feeds states in the continuum. In our calculations we assume that 7Li breaks up in two fragments: tritium and alpha particles. We plan to have the results of the CDCC calculations when this contribution is presented. of energies from well below to above the barrier, for the 7Li + 144Sm system. Moreover, barrier distributions were extracted from these measured excitation functions by a numerical method, using the ¯rst derivative of the excitation function. The analysis of the data was performed by using the code FRESCO, and the S~ao Paulo potential as a parameter free bare potential. From the analysis one concluded that the quadrupole and octupole excitations of 144Sm and the one-neutron transfer channel are important reaction processes. As we did not change any parameter of the bare potential, no attempt was made to ¯t the data, but rather to compare the experimental excitation function and the corresponding barrier distribution with theoretical predictions, using a coupling scheme that takes into account the above mentioned inelastic and transfer channels. This comparison for the excitation function gives reasonable good agreement, except at the highest energies, whereas for the barrier distribution one can notice more clearly that even at the barrier energy there is some disagreement between theoretical predictions and experimental results. This disagreement is not unexpected, since as the 7Li is a weakly bound projectile, the breakup channel should also be included in the coupling scheme. In order to verify the in°uence of the break up channel in the quasi-elastic process, at the present we are performing calculations using the CDCC method, since the break up process feeds states in the continuum. In our calculations we assume that 7Li breaks up in two fragments: tritium and alpha particles. We plan to have the results of the CDCC calculations when this contribution is presented.