Study of Charge-Exchange Reactions for constraining Stellar Electron-Capture Rates

7 Jun 2018, 11:36
18m
Kunibiki Messe (Matsue)

Kunibiki Messe

Matsue

Oral contribution Session 12

Speaker

Dr J. C. Zamora (National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, USA)

Description

Charge-exchange (CE) reactions at intermediary energies serve as a direct method for the extraction of the Gamow-Teller (GT) transition strengths, which are of importance for the estimation of weak-reaction rates for a variety of astrophysical phenomena such as core-collapse supernovae (CCSN) and the crustal heating of neutron
stars. In particular, CE reactions in the $\beta^+$ direction, like $(t,{}^{3}\text{He})$ and $(d,{}^{2}\text{He})$, are essential to determine the electron-capture (EC) rates that play a significant role in the above-mentioned scenarios.\
Recently, a ${}^{88}\text{Sr}(t,{}^{3}\text{He}+\gamma){}^{88}\text{Rb}$ experiment was performed at NSCL using the S800 spectrometer in coincidence with the gamma-ray detector array GRETINA. Experimental results provide a constrain of the EC rates on neutron-rich nuclei, around the $N=50$ line, which
are of importance for understanding the late stages of CCSN.\
In the future, $(d,{}^{2}\text{He})$ experiments in inverse kinematics will open up the opportunity to investigate CE reactions of far-from-stability nuclei. The AT-TPC, a detector based on time
projection chamber, provides a unique technique for achieving such experiments. Simulation results show a very good reconstruction of the $(d,{}^{2}\text{He})$ kinematics and
also indicate that this technique might be feasible for upcoming experiments.\
Results of the data analysis and perspectives for $(d,{}^{2}\text{He})$ experiments will be discussed.

Primary authors

Dr J. C. Zamora (National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, USA) Prof. R.G.T. Zegers (National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, USA)

Co-author

. for the E15112 collaboration (National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, USA)

Presentation Materials