[en] The predictions of the standard model (solar and electroweak) for solar neutrino experiments will be described, with special emphasis on quantitative estimates of the uncertainties in the predictions. An argument--which uses detailed Monte Carlo studies of the solar-model-predictions--will be presented which demonstrates that the existing solar neutrino experiments cannot be reconciled unless new weak interaction physics changes the shape of the ⁸Be neutrino energy spectrum. Additional arguments that suggest that new physics is required will be summarized. The predictions for next-generation experiments that are independent of details of solar models will be highlighted. An urgent appeal will be made for performing a measurement of the p(⁷Be, γ)⁸B reaction using a radioactive beam of ⁷Be

[en] The ⁷Be + p elastic cross section has been measured at the Centre de Recherches du Cyclotron RIB facility at Louvain-la-Neuve in the c.m. energy region from 0.3 to 0.75 MeV by bombarding a proton-rich target with a radioactive ⁷Be beam. The recoil protons have been detected in the angular range θ_c.m. = 120.2 deg. - 131.1 deg. and θ_c.m. = 156.6 deg. - 170.2 deg. using the LEDA system. From a R-matrix analysis of the cross section data, we extract the energy and the width of the 1⁺ resonance. The scattering lengths α₀₁ = 25 ± 9 fm (channel spin I = 1) and α₀₂ = -7 ± 3 fm (channel spin I = 2) are deduced. Implications on the low energy S-factor of the ⁷Be(p, γ)⁸B reaction are discussed

[en] The astrophysical S factor for the ⁷Be(p, γ)⁸B reaction at threshold is investigated using simple models to determine the model dependence in the extrapolation of the laboratory data to the region of astrophysical interest near 20 keV. We find that the energy dependence below 400 keV is largely well understood in terms of the Coulomb interaction and constrained by the data for the elastic scattering of low-energy neutrons from ⁷Li

[en] The electron capture nuclear decay rate is proportional to the electron density at the nucleus and affected by the chemical environment, particularly in the case of electron capturing ⁷Be. In the case of higher Z elements, such effect is expected to be negligible as the valence electrons contribute very insignificant percentage of electron density at the nucleus. The change of electron capture nuclear decay rate of ⁷Be in different chemical environments has been observed experimentally and density functional calculations calculating the change of electron density at the nucleus generally give a reasonable explanation of the effect

[en] Longitudinal momentum distributions of ⁷Be fragments following the dissociation of ⁸B on heavy, highly charged target nuclei show forward-aft asymmetries, the result of interference of electric quadrupole (E2) transitions with the dominant E1 excitation process. These asymmetries can therefore be used to gain insight into the E2 contributions to the breakup process. To assess the sensitivity of these E2 interference terms to the assumed reaction mechanism, in particular, the role of higher-order coupling effects at medium energies, coupled discretized continuum channels (CDCC) calculations are carried out for ⁸B breakup at 44 and 81 MeV/nucleon on heavy targets. The effects of higher-order processes due to both Coulomb and nuclear breakup mechanisms can be estimated. In line with earlier work we find that the asymmetries produced by the calculations are reduced when including the higher-order couplings, reflecting an effective quenching of the E2 contributions. The full CDCC calculations show less asymmetry than the available experimental data, suggesting that the structure or reaction model now contains insufficient E2 strength. This contrasts with the results of lowest-order reaction theories that conclude that the ⁸B model E2 amplitudes are too large

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[en] The study on the modifications of single particle orbitals away from the line of stability draws significant attention. In particular, there is a well known level inversion of 0d_5/2 and 1s_1/2 in case of ¹⁵C. Primarily, the neutron-rich nuclei of A = 15 isobars were studied, as compared to the proton-rich counterparts. The present work focuses on the proton-rich nucleus ¹⁵O. It is a radioactive nucleus with a half life of ∼ ¹²²s and forms the core of the borromean nucleus ¹⁷Ne. The present study involves the ¹²C(⁷Be,α) ¹⁵O transfer reaction, using a ⁷Be radioactive beam. The ⁷Be nucleus has a α−³He cluster structure and is expected to have significant transfer and breakup channels

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[en] We present weekly ⁷Be (from 1972 to 1995), and weekly/seasonal ¹⁰Be (for 1994) data in surface air from ground level stations in Sweden with a coverage of most of the northern high latitudes (56 deg. - 68 deg. N). Our Be data are regionally representative and reveal seasonal variation and coupling with tropospheric air mass from middle-low latitudes. The Be data also suggests a few percent, and sometimes episodic, incursion of stratospheric air mass. Frequent precipitation depletes the Be isotopes in the air, but cyclone events contribute to enrichments. A strong coherence between the ⁷Be record and short-term (monthly-seasonal) change in solar activity is observed which introduces a new mechanism for driving the amplitude of seasonal variation