Searching for resonances in the unbound ⁶Be nucleus by using a radioactive ⁷Be beam

K. Y. Chae, Sungkyunkwan University
D. W. Bardayan, ORNL Physics Division
J. C. Blackmon, ORNL Physics Division
M. S. Smith, ORNL Physics Division
A. E. Champagne, The University of North Carolina at Chapel Hill
R. P. Fitzgerald, The University of North Carolina at Chapel Hill
D. W. Visser, The University of North Carolina at Chapel Hill
J. J. Das, Inter University Accelerator Centre India
V. Guimarães, Universidade de São Paulo
K. L. Jones, Rutgers University–New Brunswick
S. D. Pain, Rutgers University–New Brunswick
J. S. Thomas, Rutgers University–New Brunswick
M. S. Johnson, Oak Ridge Associated Universities
R. L. Kozub, Tennessee Technological University
R. J. Livesay, Colorado School of Mines
Z. Ma, The University of Tennessee, Knoxville
C. D. Nesaraja, The University of Tennessee, Knoxville

Abstract

Knowledge of the 3He(3He,2p)4He reaction is important for understanding stellar burning and solar neutrino production. Previous measurements have found a surprisingly large rise in the cross section at low energies that could be due to a low-energy resonance in the 3He + 3He (6Be) system or electron screening. In the 6Be nucleus, however, no excited states have been observed above the first 2+ state at Ex = 1. 67 MeV up to 23 MeV, even though several are expected. The 2H(7Be,3H)6Be reaction has been studied for the first time to search for resonances in the 6Be nucleus that may affect our understanding of the 3He(3He,2p)4He reaction. A 100-MeV radioactive 7Be beam from the Holifield Radioactive Ion Beam Facility (HRIBF) was used to bombard CD2 targets, and tritons were detected by using the silicon detector array (SIDAR). A combination of reaction mechanisms appears to be necessary to explain the observed triton energy spectrum. © 2012 The Korean Physical Society.