To study the coupling effect of the positive Q-value two-neutron stripping channel in the sub-barrier of^(18)O+^(50)Cr,the fusion excitation functions were measured for the^(16,18)O+^(50)Cr systems at energies near an...To study the coupling effect of the positive Q-value two-neutron stripping channel in the sub-barrier of^(18)O+^(50)Cr,the fusion excitation functions were measured for the^(16,18)O+^(50)Cr systems at energies near and below the Coulomb barriers by using the electrostatic deflector setup.16O+^(50)Cr was selected as a reference system.The coupling effect of the low-lying collective excitation states in sub-barrier fusion was considered based on coupledchannels calculations.For^(18)O+^(50)Cr,the calculated fusion cross-sections of coupled channels,including the lowest 2^(+)vibrational states of the target nucleus and projectile,give subtle under-estimation for the experimental ones at energies below the Coulomb barrier.This means that there is limited room for the transfer effect in^(18)O+^(50)Cr,compared to the widely accepted argument of positive Q-value 2n-transfer remarkably enhancing the sub-barrier fusion cross-sections.Analogous systems of neutron-rich^(18)O-induced fusion in existing literature show the same peculiarity that the positive Q-value two-neutron stripping channel has no remarkable influence on enhancing sub-barrier fusion cross-sections.展开更多
基金Supported by the National Key R&D Program of China(2023YFA1606402,2022YFA1602302)the National Natural Science Foundation of China(U2167204,12175314,12275360,12235020)the Continuous-Support Basic Scientific Research Project。
文摘To study the coupling effect of the positive Q-value two-neutron stripping channel in the sub-barrier of^(18)O+^(50)Cr,the fusion excitation functions were measured for the^(16,18)O+^(50)Cr systems at energies near and below the Coulomb barriers by using the electrostatic deflector setup.16O+^(50)Cr was selected as a reference system.The coupling effect of the low-lying collective excitation states in sub-barrier fusion was considered based on coupledchannels calculations.For^(18)O+^(50)Cr,the calculated fusion cross-sections of coupled channels,including the lowest 2^(+)vibrational states of the target nucleus and projectile,give subtle under-estimation for the experimental ones at energies below the Coulomb barrier.This means that there is limited room for the transfer effect in^(18)O+^(50)Cr,compared to the widely accepted argument of positive Q-value 2n-transfer remarkably enhancing the sub-barrier fusion cross-sections.Analogous systems of neutron-rich^(18)O-induced fusion in existing literature show the same peculiarity that the positive Q-value two-neutron stripping channel has no remarkable influence on enhancing sub-barrier fusion cross-sections.
