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Abstract: The angular distributions for low lying states of 16O produced in the 12C(6Li, d)16O α-transfer reaction at have been measured using a high energy resolution position sensitive detection system. The measured cross section data have been analyzed by the FRDWBA theory with a particular emphasis put on the states of astrophysical interest mainly the (7.12 MeV) state. Extracted values of nuclear level parameters (excitation energy, , line width, , α-spectroscopic factor, , and reduced α-width, or ) are reported and discussed in comparison to previous ones. The used binding potential corresponds to a long nuclear interaction range (up to a channel radius ), suggesting that the channel radius is likely suitable for the calculations of reduced α-widths near the nuclear surface. However, given that previous DWBA results are available for comparison only near the channel radius , calculations have been carried out here for both three preceding a values. Formal values, and of the reduced α-widths () of the (7.12 MeV) and (6.92 MeV) states have thus been derived. Furthermore, the R-matrix analysis of various data sets of importance to the 12C()16O direct capture reaction has been carried out, leading to the range of values for the (7.12 MeV) state, , which is consistent with the preceding DWBA interval, and to a result for the E1 component of the reaction astrophysical factor, , very consistent with most constrained values previously reported in the literature. [Copyright &y& Elsevier]

Abstract: The early gamma-ray emission from novae depends critically on the reaction. Unfortunately the reaction rate of the reaction is still largely uncertain due to the unknown strengths of low-lying proton resonances near the threshold which play an important role in the nova temperature regime. We report here our last results concerning the study of the transfer reaction. We show in particular that these two low-lying resonances cannot be neglected. These results are then used to perform a careful study of the remaining uncertainties associated to the and reaction rates. [Copyright &y& Elsevier]

Coulomb excitation of the exotic neutron-rich nucleus 26Ne on a nat Pb target was measured at 58 A.MeV in order to search for low-lying E1 strength above the neutron emission threshold. Data were also taken on an nat Al target to estimate the nuclear contribution. The radioactive beam was produced by fragmentation of a 95 A.MeV 40Ar beam delivered by the RIKEN Research Facility. The set-up included a NaI gamma-ray array, a charged fragment hodoscope and a neutron wall. Using the invariant mass method in the 25Ne+n channel, we observe a sizable amount of E1 strength between 6 and 10 MeV. The reconstructed 26Ne angular distribution confirms its E1 nature. A reduced dipole transition probability of e2fm2 is deduced. For the first time, the decay pattern of low-lying strength in a neutron-rich nucleus is obtained. The results are discussed in terms of a pygmy resonance centered around 9 MeV. [Copyright &y& Elsevier]

The 11B(7Li, 7Be)11Be charge exchange reaction has been studied at an incident energy of 57 MeV. Spectra were measured at forward angles, θcm⩽35°. The good energy resolution (∼50 keV) allowed the identification of transitions both to the 7Be (3/2−, gs) and 7Be(1/2−, 429 keV) exit channels and hence the direct measurement of the ratio of the respective cross sections and angular distributions. Besides the bound ground and first excited state of 11Be several low lying excitations just above the neutron threshold are observed. A structure seen at E*=94 MeV with FWHM ∼7 MeV is compatible with the spin dipole resonance (SDR). The data are analysed in a many-body approach. For the projectile transitions shell model results are used. In order to account properly for the special features of the weakly bound 11Be system the target transitions are described microscopically by Hartree–Fock–Bogoliubov (HFB) and quasi-particle random phase approximation (QRPA) theory. The HFB ground state densities and the QRPA transition densities, respectively, are used in folding calculations for the optical potentials and transition form factors. Spectra and β-decay transitions strengths are reasonably well described. The measured cross section are well reproduced by one-step direct charge exchange distorted wave born approximation (DWBA) calculations. A dominance of unnatural parity transitions is found. This is explained in terms of the spin transfer behaviour of the nucleon–nucleon isovector interaction at low bombarding energy. [Copyright &y& Elsevier]

A 130 MeV primary tritium beam, newly developed at the superconducting cyclotron AGOR, has been used for the investigation of 1 h̵ω and 2 h̵ω isovector giant resonances in 58Co via the τ+ channel. The angular distributions of double-differential cross sections have been extracted between Ex = 7 and 30 MeV from θlab = 0° to 6°. A DWBA analysis with normal-mode (NM) wave functions and a multipole-decomposition analysis (MDA) indicate strength for the monopole resonances (dominated by the spin-flip transition) fragmented between 10 and 27 MeV excitation energy, in rather good agreement with preliminary RPA calculations. [Copyright &y& Elsevier]