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Abstract: The low-lying spectra of 8He and 10He nuclei were studied in the 3H(6He, p)8He and 3H(8He, p)10He transfer reactions. The ground state (g.s.) of 8He and excited states, at and at , were populated with cross sections of 200, 100–250, and 90–125 μb/sr, respectively. Some evidence for a 8He state at about 7.5 MeV was obtained. We discuss a possible nature of the near-threshold anomaly above 2.14 MeV in 8He and relate it to the population of a continuum (soft dipole excitation) with a peak value at about 3 MeV. The lowest energy group of events in the 10He spectrum was observed at ∼3 MeV with a cross section of . We argue that this result is consistent with the previously reported observation of 10He providing the new 10He g.s. position at about 3 MeV. [Copyright &y& Elsevier]

Abstract: By using the 1H(6Li, 6Be)n charge-exchange reaction, population of continuum states in 6Be was observed up to , being the 6Be energy above its three-body decay threshold. In kinematically complete measurements performed by detecting coincidences, an spectrum of high statistics was obtained, containing approximately events. The spectrum provides detailed correlation information about the well-known ground state of 6Be at and its state at . Moreover, a broad structure extending from 4 to 16 MeV was observed. It contains negative parity states populated by angular momentum transfer without other significant contributions. This structure can be interpreted as a novel phenomenon, i.e. the isovector soft dipole mode associated with the 6Li ground state. The population of this mode in the charge-exchange reaction is a dominant phenomenon for this reaction, being responsible for about of the cross-section obtained in the measured energy range. [Copyright &y& Elsevier]

Abstract: Rotational bands in 108,110,112Ru have been investigated by means of and coincidences of prompt γ rays emitted in the spontaneous fission of 252Cf. The positive parity bands are described by different versions of IBA, where 108Ru is best described as a γ-soft nucleus whereas 110,112Ru are more like rigid triaxial rotors. New negative parity doublet bands are found. In case of 110,112Ru, these are interpreted as soft chiral vibrations. Many of the experimental findings can be explained by microscopic calculations that combine the TAC mean-field with random phase approximation but a simple geometrical explanation is not apparent. [Copyright &y& Elsevier]

The 4H resonance was investigated in the transfer reactions 2H(t, p)4H and 3H(t, d)4H using cryogenic liquid targets of deuterium and tritium and 58 MeV triton beam. The multidetector system with a large angular acceptance was used to measure the recoil protons and deuterons in coincidences with tritons or neutrons from the decay of 4H. Data analysis involved careful considerations made for the competing processes of final state interaction and quasifree scattering. The experimental data show a peak with resonance parameters Eres=3.05±0.19 MeV and Γobs=4.18±1.02 MeV. The pole of S-matrix corresponding to the physical values of energy and width, E0=1.99±0.37 MeV and Γ0=2.85±0.3 MeV, has been extracted. [Copyright &y& Elsevier]

The 7H nucleus most likely possesses an unique decay dynamics: the four-neutron emission (or 5-body decay). We estimated theoretically the 7H width as a function of its decay energy. Uncertainty inherent to the estimated decay energy leaves a room for a possible very small width of 7H. In an attempt to observe a long living quasi stable 7H nucleus, produced in the reaction 2H(8He,7H)3He, we set an upper limit of 3nb/sr for the reaction cross section. We utilized a 20.5MeV/amu 8He beam bombarding a 5.6cm thick liquid deuterium target, and searched for 7H within 0°–50° CM angles. The obtained cross section limit corresponds to a 7H lifetime less than 1ns, which allows us to estimate a lower limit of 50–100keV for the 7H energy above the 3H+4n breakup threshold. [Copyright &y& Elsevier]

Resonance states of 5H were investigated through the two-neutron transfer reaction t(t, p)5H. A triton beam at 57.5 MeV and a cryogenic liquid tritium target were used. The 5H missing mass spectrum in triple coincidence, proton+triton+neutron, shows a resonance at 1.8±0.1 MeV above the t+2n decay threshold. This energy is in good agreement with the result reported in Phys. Rev. Lett. 87 (2001) 092501. The resonance width, Γintr⩽0.5 MeV, is surprisingly small and difficult to reconcile with theory predictions. [Copyright &y& Elsevier]

The structure of 6He is explored with proton elastic and inelastic scattering to the first 2+ excited state (Q=−1.8 MeV) of 6He in the inverse kinematics using a 24.5 A MeV 6He beam. The distorted wave approximation (DWA) with an optical potential obtained by folding an effective nucleon–nucleon (NN) g-matrix with the 6He density matrix elements as given by a large basis shell model is used to analyse the data. The comparison of predictions with the data confirms the view that 6He has an extended (halo) neutron matter distribution. [Copyright &y& Elsevier]