Inverse Kinematic Study of theAl26g(d,p)Al

Abstract

In Wolf-Rayet and asymptotic giant branch (AGB) stars, the 26g Alðp; γÞ 27 Si reaction is expected to govern the destruction of the cosmic γ-ray emitting nucleus 26 Al. The rate of this reaction, however, is highly uncertain due to the unknown properties of key resonances in the temperature regime of hydrogen burning. We present a high-resolution inverse kinematic study of the 26g Alðd; pÞ 27 Al reaction as a method for constraining the strengths of key astrophysical resonances in the 26g Alðp; γÞ 27 Si reaction. In particular, the results indicate that the resonance at E r ¼ 127 keV in 27 Si determines the entire 26g Alðp; γÞ 27 Si reaction rate over almost the complete temperature range of Wolf-Rayet stars and AGB stars.

Study of the Alm26(d,p)AlRehm1, Gerken2, Avila3 et al. 2017Phys. Rev. Lett.190160View full textAdd to dashboardCite

“…Taking into account an average value for the A = 27 mirror energy differences of ∼ 200 keV [21,49] and a 228 keV difference between the ground state and the isomeric state, the states in 27 Al which are mirrors to the astrophysically relevant states in 27 Si are expected + state in 27 Al at Eex = 3.004 MeV. The data agree with the = 0 transfer from the 5 + ground state component observed in [24]. A spectroscopic factor, C 2 S = 0.49 [24] was used to obtain the absolute beam normalization of the cross section.…”

“…The data agree with the = 0 transfer from the 5 + ground state component observed in [24]. A spectroscopic factor, C 2 S = 0.49 [24] was used to obtain the absolute beam normalization of the cross section. Angular distributions and DWBA calculations for the states in 27 Al at (b) Eex = 0.84 MeV, (c) Eex = 6.8 MeV, and (d) Eex = 10.2 MeV.…”

“…For the spectroscopic factors of the mirror states in 27 Si the same limits have been adopted. Spectroscopic factors of mirror analog states are expected to agree within 20% [24,50,51]. For the strength of the 146-keV and 378-keV resonances upper limits of 0.03 µeV and 165 meV, respectively, have been extracted.…”

“…4(a) in comparison with the recommended NACRE rate of Angulo [29,30], and the ground state rate extracted from Refs. [20,23,24].…”

“…Refs. [16][17][18][19][20][21][22][23][24] 27 Si reaction rate in WR and AGB stars is well constrained [23,24].…”