ASTROPHYSICAL IMPACT OF THE UPDATED Be-9(p,alpha)Li-6 AND B-10(p,alpha)Be-7 REACTION RATES AS DEDUCED BY THM

作者：Lamia L^*; Spitaleri C; Tognelli E; Degl'Innocenti S; Pizzone R G; Moroni P G Prada

来源：Astrophysical Journal, 2015, 811(2): 99.

DOI：10.1088/0004-637X/811/2/99

• nuclear reactions, nucleosynthesis, abundances
• stars: abundances
• stars: evolution
• stars: pre-main sequence

The complete understanding of the stellar abundances of lithium, beryllium, and boron represents one of the most interesting open problems in astrophysics. These elements are largely used to probe stellar structure and mixing phenomena in different astrophysical scenarios, such as pre-main-sequence or main-sequence stars. Their different fragility against (p,alpha) burning reactions allows one to investigate different depths of the stellar interior. Such fusion mechanisms are triggered at temperatures between T approximate to (2-5) x 10(6) K, thus defining a corresponding Gamow energy between approximate to 3-10 keV, where S(E)-factor measurements need to be performed to get reliable reaction rate evaluations. The Trojan Horse Method is a well defined procedure to measure cross sections at Gamow energies overcoming the uncertainties due to low-energy S(E)-factor extrapolation as well as electron screening effects. Taking advantage of the THM measure of the Be-9(p,alpha)Li-6 and B-10(p,alpha)Be-7 cross sections, the corresponding reaction rates have been calculated and compared with the evaluations by the NACRE collaboration, widely used in the literature. The impact on surface abundances of the updated Be-9 and B-10 (p,alpha) burning rates is discussed for pre-MS stars.

• 出版日期2015-10-1