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Title: Investigation of the triple-α reaction in a full three-body approach

Here, the triple-alpha reaction is the key to our understanding about the nucleosynthesis and the observed abundance of 12C in stars. The theory of this process is well established at high temperatures but rather ambiguous in the low temperature regime where measurements are impossible. Develop a new three-body method, which tackles properly the scattering boundary condition for three charged particles and takes into account both the resonant and the non-resonant reaction mechanisms on the same footing, to compute the triple-alpha reaction rate at low temperatures. Methods: We combine the R-matrix expansion, the R-matrix propagation method, and the screening technique in the hyperspherical harmonics basis. Both the 2+1 bound state and the 0+2 resonant state in 12C are well reproduced. We also study the cluster structure of these states. We calculate the triple-alpha reaction rate for T = 0.01 - 0.1 GK. In conclusion, we obtain the same rate as NACRE for temperatures above 0.07 GK, but the new rate is largely enhanced at lower temperatures (≈ 1012 at 0.02 GK). The differences are caused by the direct capture contribution to the reaction when three alpha particles can not reach the resonant energies.
Authors:
 [1] ;  [1] ;  [2]
  1. Michigan State Univ., East Lansing, MI (United States)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Grant/Contract Number:
FG52-08NA28552; AC52-07NA27344; PHY-0800026; SC0004087
Type:
Accepted Manuscript
Journal Name:
Physical Review. C, Nuclear Physics
Additional Journal Information:
Journal Volume: 87; Journal Issue: 5; Journal ID: ISSN 0556-2813
Publisher:
American Physical Society (APS)
Research Org:
Michigan State Univ., East Lansing, MI (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA); National Science Foundation (NSF)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; triple-alpha reaction rate; 12C hyperspherical harmonics; R-matrix; three charged-particle fusion
OSTI Identifier:
1332506
Alternate Identifier(s):
OSTI ID: 1102731