Physics – Nuclear Physics – Nuclear Theory
Scientific paper
2002-01-28
Phys.Rev.C65:054302,2002
Physics
Nuclear Physics
Nuclear Theory
23 pages 8 tables. submitted to Phys. Rev. C
Scientific paper
10.1103/PhysRevC.65.054302
The $^6$He beta decay and $^7$Be electron capture processes are studied using variational Monte Carlo wave functions, derived from a realistic Hamiltonian consisting of the Argonne $v_{18}$ two-nucleon and Urbana-IX three-nucleon interactions. The model for the nuclear weak axial current includes one- and two-body operators with the strength of the leading two-body term--associated with $\Delta$-isobar excitation of the nucleon--adjusted to reproduce the Gamow-Teller matrix element in tritium $\beta$-decay. The measured half-life of $^6$. He is under-predicted by theory by $\simeq$ 8%, while that of $^7$Be for decay into the ground and first excited states of $^7$Li is over-predicted by $\simeq$ 9%. However, the experimentally known branching ratio for these latter processes is in good agreement with the calculated value. Two-body axial current contributions lead to a $\simeq$ 1.7% (4.4%) increase in the value of the Gamow-Teller matrix element of $^6$He ($^7$Be), obtained with one-body currents only, and slightly worsen (appreciably improve) the agreement between the calculated and measured half-life. Corrections due to retardation effects associated with the finite lepton momentum transfers involved in the decays, as well as contributions of suppressed transitions induced by the weak vector charge and axial current operators, have also been calculated and found to be negligible.
Schiavilla Rocco
Wiringa R. B.
No associations
LandOfFree
Weak Transitions in A=6 and 7 Nuclei does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Weak Transitions in A=6 and 7 Nuclei, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Weak Transitions in A=6 and 7 Nuclei will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-420942