No abstract available

No abstract available

[en] A calculation of the E2 component of the ⁷Be(p,γ)⁸B cross section at low energies, using R-matrix formulae that include channel contributions, finds the resonant strength due to the 1⁺ first excited state of ⁸B to be appreciably smaller than was obtained in previous calculations, but gives a nonresonant strength slightly higher than before

[en] Evidence is presented which indicates that the accepted value for the cross section of the ⁷Be(p,γ)⁸B reaction at stellar energies is probably too large. It is suggested that the accepted value of the ⁷Li(d,p)⁸Li cross section, which has been used for normalization purposes, is too large; that the accepted value for the ratio of the ⁷Be(p,γ)⁸B and ⁷Li(d,p)⁸Li cross sections is too large; and that the energy dependence used to extrapolate to stellar energies from the higher energies at which measurements have been made is inaccurate. The consequent reduction of the ⁷Be(p,γ)⁸B cross section by about 30% would not be sufficient to resolve the solar neutrino problem but would significantly lessen the discrepancy between observation and calculation

[en] A 2^- level at 3.0 MeV in ⁸B has been suggested from ⁷Be+p elastic scattering measurements. The effect of such a level on the low-energy ⁷Be(p,γ)⁸B S factor is discussed, using R-matrix formulae with parameter values chosen to fit ⁷Li+n data. It is concluded that the level must be broad (Γ⁰≥4 MeV)

[en] Data for the ⁹Be(p, γ)¹⁰B reaction with proton energies up to 1800 keV are fitted using R-matrix formulae that include channel contributions where appropriate. The data include values of the astrophysical S factor, the branching ratios for γ-transitions to the four lowest states of ¹⁰B, angular distributions and analysing powers. Use is made of experimental values of asymptotic normalization constants obtained from ⁹Be(¹⁰B, ⁹Be) ¹⁰B. A good fit is obtained with two 1^- levels, two 2^- levels, one 0⁺ level and one 2⁺ level

[en] The lowest observed resonance in each of ⁹He and ¹⁰He is narrow, with widths 0.10±0.06 MeV and 0.3±0.2 MeV, respectively. For ⁹He, the calculated width is an order of magnitude larger. For ¹⁰He, the calculated width is appreciably larger if the observed resonance is the ground state, but consistency seems possible if it is an excited state with the ground state unobserved

[en] Values of the electron-screening potential derived from previous fits to measurements of low-energy cross sections of nuclear reactions have generally been much larger than the values estimated from model calculations. Here we refit the data using somewhat different procedures and show that better agreement is possible in some cases

No abstract available

[en] Data for the ⁹Be(p,α)⁶Li and ⁹Be(p,d)⁸Be reactions with proton energies up to 700 keV are fitted using R-matrix formulae. The data include values of the astrophysical S factors and of the angular-distribution and analysing-power coefficients. A reasonable fit is obtained with two 1^- and two 2⁺ levels of ¹⁰B, and one each of 2^-, 1⁺ and 3⁺ levels. All represent levels outside the energy range fitted except for a 1^- level at 6.87 MeV and a 2⁺ level at 6.95 MeV