Erratum: Astrophysically important 26 Si states studied with the ( 3 He, n) reaction and the 25 Al( p, γ ) 26 Si reaction rates in explosive hydrogen burning environments [Phys. Rev. C 70, 065805 (2004)]

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Additional experimental information concerning the level structure of 26 Si above the proton threshold is needed to reduce uncertainties in the 25 Al͑p , ␥͒ 26 Si reaction rate and consequently better determine 26 Al radioisotope production in astrophysical environments. The 24 Mg͑ 3 He, n͒ 26 Si reaction was measured and excitation energies of states in 26 Si were determined with improved accuracy. Spins were assigned to a number of states by comparing their measured differential cross sections with Hauser-Feshbach cross sections. The 3 + resonance state of the 25 Al͑p , ␥͒ 26 Si reaction was identified at 5912͑4͒ keV excitation energy and the 25 Al͑p , ␥͒ 26 Si reaction rate in explosive hydrogen burning environments was calculated.

Ericson fluctuations in the differential cross sections were investigated for the compound reactions 27 Al͑p , n 0 ͒ 27 Si, 45 Sc͑p , n 4 ͒ 45 Ti, 45 Sc͑p , n 5 ͒ 45 Ti, 51 V͑p , n 0 ͒ 51 Cr, and 59 Co͑p , n 0 ͒ 59 Ni. Level widths in the compound nuclei 28 Si, 46 Ti, 52 Cr, and 60 Ni were extracted from the analysis of the differential cross sections by the Fourier method and a nonlinear fit to the ln͗A k 2 + B k 2 ͘ distribution. The neutron spectra for each reaction were measured at least at three backward angles but the coherence width ͗⌫͘ did not show a strong angular dependence. Nuclear level densities for the above nuclei were extracted by relating the average level spacing D J to the average level width ⌫ J using the fluctuation theory. Reasonable agreements were found with other level densities and level density compilations based in the Fermi gas formalism of Al-Quraishi and Huang for 28 Si, 46 Ti, and 52 Cr but the comparison diverges for 60 Ni for which additional measurements are required in order to clarify the observed discrepancies. The level density parameters that best describe the data are a = 3.5 and ␦ = 4.0, U Ͻ 25 MeV, for 28 Si, a = 4.8 and ␦ = −0.3, U Ͻ 20 MeV, for 46 Ti, and a = 4.8 and ␦ = 0.3, U Ͻ 20 MeV, for 52 Cr.