Abstract
The discrepancy between observations from -ray astronomy of the -ray flux ratio and recent calculations is an unresolved puzzle in nuclear astrophysics. The stellar -decay rate of is one of the major nuclear uncertainties impeding us from a precise prediction. The important Gamow-Teller strengths from the low-lying states in to the ground state are measured for the first time using the exclusive measurement of the charge-exchange reaction. The new stellar decay rate of is a factor of larger than the currently adopted rate at . Stellar evolution calculations show that the production yield of an 18 solar mass star is decreased significantly by 40% when using the new rate. Our result eliminates one of the major nuclear uncertainties in the predicted yield of and alleviates the existing discrepancy of the ratio.
- Received 22 December 2020
- Revised 20 February 2021
- Accepted 17 March 2021
DOI:https://doi.org/10.1103/PhysRevLett.126.152701
© 2021 American Physical Society