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Precise quasielastic experimental excitation function for the 18O+65Cu system has been measured and its barrier distribution has been derived. Several reaction channels have been observed on the experimental spectra, revealing the presence of two-neutron and α-stripping processes, as well as the proton pickup transfer, for which excitation functions were also measured. Extensive coupled channel and coupled reaction channel calculations have been performed to describe the experimental data. The inelastic couplings of target and projectile, and the ground state reorientation of the target, were important to the proper description of data. The transfer data were well described by calculations; however, it was shown that they almost do not affect the excitation function of 18O+65Cu quasielastic scattering. Whenever possible, structure shell model calculations have been performed to obtain the spectroscopic amplitudes of projectile and target overlaps. The two-neutron and α-transfer reactions have been calculated considering the transferred particle as a cluster with spin 0. [ABSTRACT FROM AUTHOR]

We have measured a precise quasielastic excitation function for the 16O+65Cu system, at θLAB=161∘, and at bombarding energies near the Coulomb barrier. A quasielastic barrier distribution for this system was deduced from the experimental quasielastic excitation function. An α-stripping excitation function has also been measured at the same experimental conditions. These new data have been used to investigate the relative importance of several reaction channels in the reaction mechanism of the 16O+65Cu system. Large-scale coupled-channel calculations and coupled-reaction-channel calculations have been performed. No imaginary potential was used at the barrier region because many channels have been explicitly included in the calculations. Only an inner short-range potential was used to account for the fusion process. We did not fit data by varying potential parameters, and our theoretical results were compared directly to data. Good agreement was found between data and calculations. Owing to the high sensitivity of the barrier distribution, important results have been obtained. The first excited state (1/2-) of 65Cu has less influence in the reaction mechanism than the second (5/2-) and third (7/2-) states, which are the most relevant among all the investigated ones. We have also observed a striking influence of the reorientation of the ground-state spin of the 65Cu nucleus on the elastic scattering at backward angles. In addition, calculations have shown that the excitation of the states 3-,2+,1-, and 2- of the projectile 16O are also important for excellent agreement obtained with both the excitation function and the distribution of barriers. The α-stripping data have been compared to the results of coupled-reaction-channel calculations and good agreement was obtained with the inclusion of the first excited state of 12C in the coupling scheme. However, the α-transfer process has a small influence on the reaction dynamics of this system at the investigated energies. [ABSTRACT FROM AUTHOR]

A precise quasielastic excitation function for the 18O+63Cu system has been measured at energies around the Coulomb barrier at θLAB=161°. The corresponding quasielastic barrier distribution has been derived. Two-neutron-, one-proton-, and a-transfer-excitation functions have also been measured at the same energies and angle. Coupled reaction channels calculations were performed to describe the experimental data. Large-scale shell-model calculations were performed to derive most of the spectroscopic amplitudes. No surface imaginary potential was necessary for the interaction potential because almost all relevant reaction channels were explicitly included in the calculation. The theoretical results were compared to the experimental quasielastic barrier distribution and a very good agreement was achieved. The comparison of the coupled reaction channel calculations and data has put in evidence several important details of the reaction mechanism of the 18O+63Cu system. The collectivity of the 63Cu nucleus has important contribution to the reaction mechanism of this system, mainly due to its first 5/2+ and 7/2+ states. It was also observed a striking influence on the reaction dynamics of the 18O(2+) state, the two-neutron transfer and the reorientation of the target ground-state spin. The best agreement to data was achieved when the nuclear matter diffuseness for the 18O was assumed equal to 0.60 fm, value that we have derived in a previous paper and that is 10% greater than the 16O diffuseness. Another significant result was that the two-neutron transfer process is much more relevant than the one-neutron-transfer process, which suggests that the pairing correlation could play an important role in the transfer process of this system. [ABSTRACT FROM AUTHOR]

The elastic scattering angular distribution of the 16O+60Ni system at 260 MeV was measured in the range of the Rutherford cross section down to seven orders of magnitude. The cross sections of the lowest 2+ and 3- inelastic states of the target were also measured over several orders of magnitude. Coupled-channel (CC) calculations were performed and are shown to be compatible with the whole set of data only when including the excitation of the projectile and when the deformations of the imaginary part of the nuclear optical potential are taken into account. Similar results were obtained when the procedure is applied to the existing data on 16O+27Al elastic and inelastic scattering at 100 and 280 MeV. An analysis in terms of dynamical polarization potentials (DPP) indicates the major role of coupled-channel effects in the overlapping surface region of the colliding nuclei. [ABSTRACT FROM AUTHOR]

Experimental angular distributions for the 7Li+120Sn elastic and inelastic (projectile and target excitations) scattering, and for the neutron stripping reaction, have been obtained at ELAB=20, 22, 24, and 26 MeV, covering an energy range around the Coulomb barrier (V(LAB)B21.4 MeV). Coupled channel and coupled reaction channel calculations were performed and both describe satisfactorily the experimental data sets. The 12- state 7Li inelastic excitation (using a rotational model), as well as the projectile coupling to the continuum (a plus a tritium particle) play a fundamental role on the proper description of elastic, inelastic, and transfer channels. Couplings to the one-neutron stripping channel do not significantly affect the theoretical elastic scattering angular distributions. The spectroscopic amplitudes of the transfer channel were obtained through a shell model calculation. The theoretical angular distributions for the one-neutron stripping reaction agreed with the experimental data. [ABSTRACT FROM AUTHOR]

In this paper we discuss new experimental data on the one-proton transfer reaction 32S(3He, d)33Cl* at 9.68 MeV bombarding energy. An enriched 32S target and a high-granularity hodoscope were used to obtain data for proton transfer reactions to bound and unbound states in 33Cl. Angular distributions were interpreted by means of finite-range DWBA and coupled-channel calculations. The obtained spectroscopic factors have been compared with previous results reported in the literature and with shell model calculations. [ABSTRACT FROM AUTHOR]

Background: Neutron transfer measurements for the 18O+28Si system have shown that the experimental one-neutron and two-neutron transfer cross sections are well reproduced with spectroscopic amplitudes from two different shell-model interactions for the Si isotopes: psdmod for the two-neutron transfer, and psdmwkpn for the one-neutron transfer. Purpose: The need for two distinct shell-model interactions to reproduce two neutron-transfer processes in the same nuclei may cover a more complex mechanism in the one-neutron transfer that requires the unpairing of neutrons prior to its transfer in the (18O,17O) reaction. Studying a nucleus where this characteristic is absent (13C) should help to elucidate this question. Method: One-neutron transfer cross sections were measured for the 13C+28Si at Elab=30 and 34 MeV, and compared with coupled reaction channel calculations using spectroscopic amplitudes derived from the psdmod and psdmwkpn shell-model interactions. Results: The spectroscopic amplitudes from the psdmod interaction for the relevant states in 29Si provide a good description of the experimental data and the corresponding values agree with previous estimates obtained from the (d,p) reaction. Conclusions: The experimental data for the one-neutron transfer to 28Si induced by (13C,12C) reaction is well reproduced using spectroscopic amplitudes from the psdmod. [ABSTRACT FROM AUTHOR]

The precise quasielastic excitation function for the 18O+64Zn system was measured at energies near and below the Coulomb barrier at θlab=161∘, from which its correlated quasielastic barrier distribution was derived. The excitation functions for the two-neutron, α, and tritium transfer reactions have also been measured at the same conditions. These data were well described by the coupled channel and coupled reaction channel calculations. The comparison of the data with theoretical calculations shows the strong influence of three inelastic channels in the coupling process: the quadrupole and octupole vibrational states of 64Zn, 2+1 and 3-1, and the quadrupole vibrational state of 18O, 2+1. In addition, theoretical calculations indicate that the two-neutron stripping is mostly due to a one-step process, which has a striking effect on the reaction mechanism of this system. [ABSTRACT FROM AUTHOR]

The nuclear scattering at energies well above the Coulomb barrier allows for a fairly sensitive examination of the parameters of the optical potential when the relevant couplings are included into the calculations. In this work we present experimental angular distribution data for the elastic and inelastic scatterings of 16O impinging on 27Al and 28Si target nuclei at Elab=240MeV. The experimental data were measured at 7∘<θc.m.<16∘ with good angular resolution. Experimental data are compared with coupled channel calculations with the inclusion of couplings to excited states in the target and projectile. We show that the shape of angular distributions are sensitive to the mass diffuseness parameter and the best agreement is achieved for a=0.62fm. [ABSTRACT FROM AUTHOR]

We present new experimental angular distributions for the elastic scattering of 6Li + 120Sn at three bombarding energies. We include these data in a wide systematic involving the elastic scattering of 4,6He, 7Li, 9Be, 10B, and 16,18O projectiles on the same target at energies around the respective Coulomb barriers. Considering this data set, we report on optical model analyses based on the double-folding São Paulo potential. Within this approach, we study the sensitivity of the data fit to different models for the nuclear matter densities and to variations in the optical potential strengths. [ABSTRACT FROM AUTHOR]

Background: Recently, a systematic exploration of two-neutron transfer induced by the (18O,16O) reaction on different targets has been performed. The high-resolution data have been collected at the MAGNEX magnetic spectrometer of the INFN-LNS Laboratory in Catania and analyzed with the coupled reaction channel (CRC) approach. The simultaneous and sequential transfers of the two neutrons have been considered under the same theoretical framework without the need for adjustable factors in the calculations. Purpose: A detailed analysis of the one-neutron transfer cross sections is important to study the sequential two-neutron transfer. Here, we examine the (18O,17O) reaction on 16O,28Si, and 64Ni targets. These even-even nuclei allow for investigation of one-neutron transfer in distinct nuclear shell spaces. Method: The MAGNEX spectrometer was used to measure mass spectra of ejectiles and extract differential cross sections of one-neutron transfer to low-lying states. We adopted the same CRC formalism used in the sequential two-neutron transfer, including relevant channels and using spectroscopic amplitudes obtained from shell-model calculations. We also compare with the one-step distorted-wave Born approximation (DWBA). Results: For the 18O+16O and the 18O+28O systems, we used two interactions in the shell model. The experimental angular distributions are reasonably well reproduced by the CRC calculations. In the 18O+64Ni system, we considered only one interaction, and the theoretical curve describes the shape and order of magnitude observed in the experimental data. Conclusions: Comparisons between experimental DWBA and CRC angle-integrated cross sections suggest that excitations before or after the transfer of a neutron are relevant in the 18O+16O and 18O+64Ni systems. [ABSTRACT FROM AUTHOR]

The 10B+120Sn reaction has been systematically studied at laboratory energies around the Coulomb barrier: ELAB=31.5, 33.5, 35.0, and 37.5 MeV. Cross sections for the elastic scattering and some reaction processes have been measured: excitation to the 1+ state of 10B; excitation to the 2+ and 3- states of 120Sn; and the one-neutron pick-up transfer 120Sn(10B,11B)119Sn. Coupled reaction channel (CRC) calculations have been performed in the context of the double-folding São Paulo potential. The theoretical calculations result in a good overall description of the experimental angular distributions. The effect on the theoretical elastic-scattering angular distributions of couplings to the inelastic and transfer states (through the CRC calculations) and to the continuum states (through continuum-discretized coupled-channels calculations) has been investigated. [ABSTRACT FROM AUTHOR]

The 10B+120Sn reaction has been investigated at ELab=37.5 MeV. The cross sections for different channels, such as the elastic scattering, the excitation of the 2+ and 3-120Sn states, the excitation of the 1+ state of 10B, and the 1n pick-up transfer, have been measured. One-step distorted-wave Born approximation and coupled-reaction-channels calculations have been performed in the context of the double-folding São Paulo potential. The effect of coupling the inelastic and transfer states on the angular distributions is discussed in the paper. In general, the theoretical calculations within the coupled-reaction-channels formalism yield a satisfactory agreement with the corresponding experimental angular distributions. [ABSTRACT FROM AUTHOR]

Background: In our recent work [M. J. Ermamatov et al., Phys. Rev. C 94, 024610 (2016)], the two-neutron transfer induced by the (18O,16O) reaction was studied for 16O nucleus. Theoretical analysis of the low-lying states of 18O indicates that the transfer to the ground state proceeds predominantly through simultaneous transfer of the two-neutron system. Purpose: In this work, we extend our previous theoretical analysis towards high-lying states of the 18O nucleus. In order to achieve a comprehensive picture, we revisit the experimental data for the 16O(t,p)18O reaction at 15 MeV bombarding energy. We also include new experimental cross sections for the high-lying states of the 18O residual nucleus, populated in the 16O(18O,16O)18O reaction at 84 MeV. Method: The same spectroscopic parameters of the target nucleus were used as input in the coupled channel calculations for the transfer induced by triton and 18O projectiles. Simultaneous two-neutron transfer is calculated within the coupled reaction channel approach, using the extreme cluster and independent coordinate models. The sequential process is calculated within the distorted-wave Born approximation. Results: Theoretical calculations reproduce the 16O(t,p)18O data well, leading to natural parity states in the 18O nucleus without the need of adjustable parameters. The same methods are applied to the 16O(18O,16O)18O data and a good agreement is observed. Conclusions: Detailed analyses show the importance of a simultaneous mechanism for the two-neutron transfer reactions. In transferring two neutrons, the pairing correlation plays an important role. [ABSTRACT FROM AUTHOR]

The complete set of open channels for the 7Li+p system, namely elastic scattering, inelastic scattering, breakup, the 7Li+p→7Be+n charge exchange reaction, and the 7Li+p→4He+4He reaction, was measured in the same experiment in inverse kinematics at an energy of 5.44 MeV/u. Data were also obtained for the charge exchange reaction at energies of 5.0 and 3.57 MeV/u. The elastic and inelastic scattering and breakup data were reported previously and are reviewed here and, together with the new data for the other two reactions, are discussed coherently within the same continuum-discretized coupled-channels model framework. [ABSTRACT FROM AUTHOR]

An exclusive measurement of the breakup of 7Li incident on a proton target was performed at 38.1 MeV (5.44 MeV/nucleon), probing the direct part of the excitation to the continuum. The two cluster constituents of 7Li, 4He, and ³H, were recorded in coincidence in the MAGNEX spectrometer and a silicon detector respectively. Both detection systems were set at forward angles and the measurement of both kinematical solutions allowed the determination of a breakup angular distribution over a wide angular range in the center-of-mass frame. Comprehensive simulations provided the detection efficiency of the system and via the appropriate kinematics the transformation of the cross sections from the laboratory to the center-of-mass reference frame. The experimental results are analyzed and discussed together with previous elastic scattering data using the Continuum Discretized Coupled Channels (CDCC) framework and are found to be in satisfactory agreement. It was found that while the breakup cross section was dominated by the nonresonant component, the most important influence on the elastic scattering was due to coupling to the 7/2- resonance of 7Li. [ABSTRACT FROM AUTHOR]

Elastic scattering measurements were performed for the 7Li+p system in inverse kinematics at energies of 16, 25, 35, and 38.1 MeV and for the 7Li+d system at 38.1 MeV. The heavy ejectiles were detected by the large acceptance MAGNEX spectrometer at the Laboratori Nazionali del Sud in Catania, Italy. The results are analyzed using the Jeukenne-Lejeune-Mahaux and continuum discretized coupled channel frameworks. In the latter case the cluster structure of 7Li proves to be critical for the theoretical interpretation of the experimental results. [ABSTRACT FROM AUTHOR]