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One-neutron stripping process between 6Li and 209Bi was studied at 28, 30, and 34 MeV using the in-beam γ-ray spectroscopy method. The γ–γcoincident analysis clearly identified two γ-rays feeding the ground and long-lived isomeric states, which were employed to determine the cross section. The one-neutron stripping cross sections were similar to the cross sections of complete fusion in the 6Li+209Bi system, but the one-neutron stripping cross sections decreased more gradually at the sub-barrier region. A coupled-reaction-channel calculation was performed to study the detailed reaction mechanism of the one-neutron stripping process in 6Li. The calculations indicated that the first excited state of 5Li is critical in the actual one-neutron transfer mechanism, and the valence proton of 209Bican be excited to the low-lying excited state in (6Li,5Li) reaction, unlike in the (d,p) reaction.

Light elements were produced in the first few minutes of the Universe through a sequence of nuclear reactions known as Big Bang nucleosynthesis (BBN)1,2. Among the light elements produced during BBN1,2, deuterium is an excellent indicator of cosmological parameters because its abundance is highly sensitive to the primordial baryon density and also depends on the number of neutrino species permeating the early Universe. Although astronomical observations of primordial deuterium abundance have reached percent accuracy3, theoretical predictions4–6based on BBN are hampered by large uncertainties on the cross-section of the deuterium burning D(p,γ)3He reaction. Here we show that our improved cross-sections of this reaction lead to BBN estimates of the baryon density at the 1.6 percent level, in excellent agreement with a recent analysis of the cosmic microwave background7. Improved cross-section data were obtained by exploiting the negligible cosmic-ray background deep underground at the Laboratory for Underground Nuclear Astrophysics (LUNA) of the Laboratori Nazionali del Gran Sasso (Italy)8,9. We bombarded a high-purity deuterium gas target10with an intense proton beam from the LUNA 400-kilovolt accelerator11and detected the γ-rays from the nuclear reaction under study with a high-purity germanium detector. Our experimental results settle the most uncertain nuclear physics input to BBN calculations and substantially improve the reliability of using primordial abundances to probe the physics of the early Universe.

The transition between the Main Sequence and the Red Giant Branch in low mass stars is powered by the onset of CNO burning, whose bottleneck is 14N(p, $\gamma)^{15}$O. The LUNA collaboration has recently improved the low energy measurements of the cross section of this key reaction. We analyse the impact of the revised reaction rate on the estimate of the Globular Cluster ages, as derived from the turnoff luminosity. We found that the age of the oldest Globular Clusters should be increased by about 0.7-1 Gyr with respect to the current estimates.

The 14N(p,γ)15O reaction has been investigated by the LUNA experiment at the National Laboratory of Gran Sasso (LNGS). This study has been performed with two different setups. The first one, suitable for the detection of γ-rays produced by single transitions, has been based on an HPGe detector and a solid target. In a second phase, we used a BGO summing crystal as a detector and a windowless gas target. The BGO high detection efficiency and the target purity allowed us to measure the total S factor down to Ecm = 70 keV.

CLARA is an array of 25 Clover (EUROBALL type) Ge detectors, placed at the target position of the large acceptance magnetic spectrometer PRISMA. Due to the granularity of the CLARA Ge array (100 crystals), the photopeak efficiency (≈3%) and the PRISMA large acceptance (≈80 msr, and 20% Δp/p), the setup is an excellent tool to investigate the structure of neutron-rich nuclei, populated in multinucleon transfer reactions and deep inelastic collisions with stable beams. Since March 2004 the setup is fully operational, and since then several experiments have been performed, with beams delivered by the LNL XTU-Tandem and the ALPI linac. In this contribution the preliminary outcome of the first experiments is shown.

Based on the energy spectra and relative transition probabilities 176,178,180Os turned out to be very promising candidates for testing the features of the critical point symmetry X(5). In order to also test absolute transition probabilities predicted in the framework of the X(5) symmetry lifetime measurements were performed at the Cologne FN tandem accelerator. The lifetimes of the first 2+ states in 176,178,180Os were measured using electronic timing and in the case of 178Os with the recoil distance Doppler shift (RDDS) technique using an 16O-induced fusion evaporation reaction. In addition, a coincidence RDDS measurement was performed at the Laboratori Nazionali di Legnaro with the GASP spectrometer using the 154Sm(29Si,5n)178Os reaction. The deduced transition quadrupole moments agree well with the X(5) predictions, thus further supporting an X(5) structure for 178Os. The experimental data for 178Os are compared to calculations in the framework of the interaction boson model (IBM) and of the general collective model (GCM).

The reactions ¹⁶O(⁷Li, 2n) and ¹⁶O(⁷Li, np) populating ²¹Na and ²¹Ne have been studied at E_L &equal; 27 MeV using the GASP γ-detector array. The level scheme for ²¹Na and ²¹Ne has been extended to higher excitation energy. Spins and parities of the observed levels are assigned tentatively supporting the identification of opposite parity structures connected by strong dipole transitions. The structure of these bands is interpreted as based on a reflection asymmetric cluster structure.

Abstract:: High-spin states in 142Gd have been populated by means of the 99Ru(48Ti, 2p3n) reaction at 240 MeV and investigated with the γ-spectrometer EUROBALL III and the charged-particle detector array ISIS. The features of four dipole bands have been determined and compared with tilted-axis cranking model calculations indicating that they are magnetic rotational bands. A transition from regular to irregular bands has been found approaching N = 82 demonstrating that this is a general phenomenon in nuclei near a double-shell closure.

Abstract.: Gamma ray transitions de-exciting states in the N = Z nucleus 70Br have been identified for the first time using the GASP and EUROBALL arrays coupled with ancillary detectors. The level scheme of 70Br has been established by means of particle-gated γ-γ and γ-γ-γ coincidences. The Coulomb energy differences between isobaric analogue states in 70Br and 70Se show a deviation from the expected behaviour which could be related to dripline effects.

Abstract:: High-spin states in 178Ir were investigated by means of in-beam γ-ray spectroscopy techniques using the multidetector array GASP. Excited states of 178Ir were populated through the 159Tb(24Mg, 5n) fusion-evaporation reaction at E(24 Mg) = 131-141 MeV. Several rotational bands were observed. Among them, the πi 13/2⊗νi 13/2 structure has been identified up to spin 36 ?. This band exhibits an anomalous signature splitting and a signature inversion around spin 25 ?.

Mean lifetimes have been measured for superdeformed bands of 145Gd with the Doppler-shift attenuation method. The extracted quadrupole moments of the yrast and first excited superdeformed bands are Q0=11.8±0.8eb and Q0=13.2±1.0eb, respectively. The configuration assignments based on the quadrupole moments are π61π[404]9/2ν[514]9/2ν70for the yrast superdeformed band and π62ν[642]5/2ν70for the first excited superdeformed band between the two known crossings.

A high-sensitivity?-spectroscopic study of the149Hoph11/2 andps1/2ß-decays using mass separated sources has located dominant 0+ ? 1+ GT decay strength associated with decay of pairedh11/2 protons, leading to 3?-states in the149Dy daughter nucleus. In their?-decay low-lying149Dy levels characteristic of anN=83 nucleus are excited. They include the?f7/2,?p3/2,?h9/2 and?p1/2 single particle- and the?s12/-1 and?d32/-1 two-particle one-hole states, as well as the ?f7/2 × 3- and?f7/2 × 2+ particle-phonon multiplets. A synopsis is given of these excitations in theN=83 isotones from149Nd to153Yb. The149Dy GT decay strength is discussed in terms of the147Tb82 and148Dy82 decays. The strength function results are also compared with independent149Ho 11/2- decay data from the literature based on total?-ray absorption measurements.

The g-factor of the 2₊¹ state in ₁₈₀Pt has been measured by means of an implantation-decay technique in conjunction with the -ray detector array GASP, thereby extending the g(2₊¹) systematics for Pt isotopes across the upper part of the valence neutron shell, beginning below mid-shell. Despite the variation in the number of valence neutron holes from 6 to 22, the g-factors remain nearly constant and near 0.7Z/A.

With a summation-free ß+-endpoint spectrometer the ß+-decay energies of104Sn,147Tb,148, 149Dy,149Ho,150Er, and151Tm were remeasured with improved accuracy. Combined with known proton and alpha decay energies, the resulting QEC values lead to atomic masses of very neutron-deficient isotopes including nuclei beyond the proton drip-line such as109I and113Cs. Furthermore, the Gamow-Tellerß-strength of the even-even nuclei104Sn,148Dy, and150Er is reevaluated with reduced uncertainty.

Abstract:: The even-even nucleus 122Ba was studied via in-beam γ-ray spectroscopy using the 40Ca + 92Mo reaction at 190 MeV. Five bands were observed, four more that can be found in the literature. Configurations were assigned to the various bands from the comparison with the neighboring even-even nuclei.

Abstract:: The even-even nucleus 128Nd was studied via in-beam γ-ray spectroscopy using the 40Ca + 82Mo reaction at 190 MeV. Two new bands were observed besides the yrast one, that has been extended up to spin 34+. Configurations were assigned to the three bands by analysing their rotational properties and by comparison with the neighboring even-even nuclei.

Abstract:: The ridge structure with ΔEγ=±30 keV, observed in the past in coincidence with protons emitted in the reaction 187 MeV 37Cl +120Sn and attributed to an hyperdeformed nuclear shape in 152Dy, has been studied in a new experiment performed with the EUROBALL III array. The ridge is now observed in coincidence with transitions in the yrast superdeformed band of 152Dy but no discrete rotational bands have been identified.

Abstract.: The 178Pt and 181Au nuclei have been studied with the (230 MeV) 46Ti +142Nd fusion-evaporation reaction; γ-rays, evaporated particles and recoiling nuclei have been detected by the γ-array GASP + the Si ball ISIS + the recoil mass spectrometer RMS. The newly observed structures in 178Pt and 181Au are most probably built on the proton and quasi-proton h9/2 and i13/2 configurations.

The N=84 nucleus154Yb was investigated through the106Cd(54Fe,a2p) reaction. We found the 16+ yrast level in this nucleus to be formed by the (ph11/22?f7/2h9/2) configuration, in contrast to the lower-Z isotones where (ph11/22?f7/22)16+ is the yrast state. Manybody shell model calculations with empirical two-body interactions support our conclusion.

In a high sensitivity (α,2nγ) in-beam study of62144Sm82, with the Kölner Würfel OSIRIS γ-detector array including a Compton polarimeter, we have identified the complete two-proton multiplets πd52/−2, πd52/−1g72/−1, πg72/−2, πh11/2d52/−1 and the 9− to 4− members of the πh11·/2g72/−1 multiplet.

In-beam??- and??n-measurements have for the first time identified excited states in the72157Hf85 nucleus and have established its yrast levels up to 6.5 MeV and I=(51/2). The results of parameter-free 11-particle recoupling calculations in the framework of the shell model for the configurationsph112/8?f72/3 andph112/8?f72/2h9/2 are in excellent agreement with the observed levels up to 39/2 at 4.758 MeV. A weakly populated 52 ns 29/2+ yrast isomer at 2.876 MeV is assigned as the three-neutron configuration?f7/2h9/2i13/2.

Further analysis of earlier152Gd(α,4n) in-beam data revealed several previously unplaced152Dy γ-rays feeding the oblate yrast states, among them γ-transitions emitted in decay of the superdeformed band. We can also weakly detect the lowest two members of the superdeformed cascade, but our data were not quite good enough to make a firm connection to them.

Studies of the149Ho 11/2- and 1/2+ GT-decays using on-line mass separation have established in the N=83149Dy nucleus the single neutron excitations below 1.8 MeV and members of the ?f7/2×3- and ?f7/2×2+ particle-phonon multiplets. Quantitative analysis of the GT-decay strength to149Dy 1qp- and 3qp-states is made in terms of the strength values measured in149Dy0 and147Tb11/2- decay.

In the present paper we present part of the results obtained in the study of above-yrast states in 145Sm using the 142Nd(α,Xnγ) reaction. γ-γ, angular distribution, polarization, and excitation function measurements were performed. All multiplet members of the and the multiplets have been observed. The unperturbed energies for the multiplet have been estimated using the extensive information existing on one neutron transfer reactions. The results are compared with the 143Nd case. The similarity is remarkable.

Context.The NO cycle takes place in the deepest layer of a H-burning core or shell, when the temperature exceeds T≃ 30  ×  106K. The O depletion observed in some globular cluster giant stars, always associated with a Na enhancement, may be due to either a deep mixing during the red giant branch (RGB) phase of the star or to the pollution of the primordial gas by an early population of massive asymptotic giant branch (AGB) stars, whose chemical composition was modified by the hot bottom burning. In both cases, the NO cycle is responsible for the O depletion.