The Li-8(p, alpha)He-5 reaction at low energies, and Be-9 spectroscopy around the proton threshold

Autor(es):Mostrar menos -

Mendes, Jr., D. R. ^[1] ; Lepine-Szily, A. ^[1] ; Descouvemont, P. ^[2] ; Lichtenthaeler, R. ^[1] ; Guimaraes, V. ^[1] ; de Faria, P. N. ^[1] ; Barioni, A. ^[1] ; Pires, K. C. C. ^[1] ; Morcelle, V. ^[1] ; Pampa Condori, R. ^[1] ; Morais, M. C. ^[1] ; Leistenschneider, E. ^[1] ; Lima, C. E. F. ^[1] ; Zamora, J. C. ^[1] ; Alcantara, J. A. ^[1] ; Zagatto, V. ^[1] ; Assuncao, M. ^[3] ; Shorto, J. M. B. ^[4]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Fis, Dept Fis Nucl, BR-05315970 Sao Paulo - Brazil

^[2] ULB, B-1050 Brussels - Belgium

^[3] Univ Fed Sao Paulo, Dept Ciencias Exatas & Terra, Sao Paulo - Brazil

^[4] Comissao Nacl Energia Nucl, Inst Pesquisas Energet & Nucl IPEN CNEN, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Physical Review C; v. 86, n. 6 DEC 26 2012.
• Citações Web of Science: 7

Resumo

We present a direct measurement of the low-energy Li-8(p, alpha)He-5 cross section, using a radioactive Li-8 beam impinging on a thick target. With four beam energies, we cover the energy range between E-c.m. = 0.2 and 2.1 MeV. An R-matrix analysis of the data is performed and suggests the existence of two broad overlapping resonances (5/2(+) at E-c.m. = 1.69 MeV and 7/2(+) at E-c.m. = 1.76 MeV). At low energies our data are sensitive to the properties of a subthreshold state (E-x = 16.67 MeV) and of two resonances above threshold. These resonances were observed in previous experiments. The R-matrix fit confirms spin assignments, and provides partial widths. We propose a new Li-8(p, alpha)He-5 reaction rate and briefly discuss its influence in nuclear astrophysics. DOI: 10.1103/PhysRevC.86.064321 (AU)

• Processo FAPESP: 03/10099-2 - O estudo de núcleos exóticos com feixes radioativos produzidos no laboratório Pelletron-Linac do IFUSP
• Beneficiário: Alinka Lépine
• Modalidade de apoio: Auxílio à Pesquisa - Programa PRONEX - Temático
• Processo FAPESP: 04/07379-6 - Estudo da reacao h(8li, alfa)5he com feixe radiativo 8li.
• Beneficiário: Djalma Rosa Mendes Junior
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 08/09341-7 - O estudo de núcleos fora da linha de estabilidade com feixes de núcleos exóticos
• Beneficiário: Rubens Lichtenthäler Filho
• Modalidade de apoio: Auxílio à Pesquisa - Regular