Ground-state proton decay of 69Br and implications for the 68Se astrophysical rapid proton-capture process waiting point.
نویسندگان
چکیده
We report on the first direct measurement of the proton separation energy for the proton-unbound nucleus (69)Br. Bypassing the (68)Se waiting point in the rp process is directly related to the 2p-capture rate through (69)Br, which depends exponentially on the proton separation energy. We find a proton separation energy for (69)Br of Sp((69)Br )= -785(-40)(+34) keV; this is less bound compared to previous predictions which have relied on uncertain theoretical calculations. The influence of the extracted proton separation energy on the rp process occurring in type I x-ray bursts is examined within the context of a one-zone burst model.
منابع مشابه
Nuclear isomers: structures and applications
Isomeric states in the nuclei along the rapid proton capture process path are studied by the projected shell model. Emphasis is given to two waiting point nuclei 68Se and 72Kr that are characterized by shape coexistence. Energy surface calculations indicate that the ground state of these nuclei corresponds to an oblate-deformed minimum, while the lowest state at the prolatedeformed minimum can ...
متن کاملTwo-Proton Decay Experiments at MSU
First evidence for direct two-proton radioactivity has been observed in the decay of the first excited state of Ne. The decay is in competition with the -decay back to the ground state of Ne and from the branching ratio the lifetime for the two-proton decay is estimated to be 0.9 ps. The proton-proton angular distribution is statistically not significant to observe any correlations. The first e...
متن کامل0 Mapping the proton drip line from Z = 31 to Z = 49
The structure of proton drip line nuclei in the 60 < A < 100 mass range is studied with the Relativistic Hartree Bogoliubov (RHB) model. For the elements which determine the astrophysical rapid proton capture process path, the RHB model predicts the location of the proton drip-line, the ground-state quadrupole deformations and one-proton separation energies at and beyond the drip-line. The resu...
متن کاملNUCLIDES OF ASTROPHYSICS INTEREST WITH MASS NUMBERS CLOSE TO A~80 PNPI participants of the IGISOL/JYFLTRAP collaboration
Nuclei close to the N = Z line in the region near A = 80 play a special role in nuclear astrophysics since the rapid proton (rp) capture process is passing right through them (see Fig. 1). The rp-process, a sequence of rapid proton captures and β-decays, proceeds along the N = Z line up to Ni and it can continue ending in a SnSbTe cycle either in explosive X-ray bursts or in a steady state burn...
متن کاملStellar weak decay rates in neutron-deficient medium-mass nuclei
Weak decay rates under stellar density and temperature conditions holding at the rapid proton-capture process are studied in neutron-deficient medium-mass waiting-point nuclei extending from Ni up to Sn. Neighboring isotopes to these waiting-point nuclei are also included in the analysis. The nuclear structure part of the problem is described within a deformed Skyrme Hartree-Fock + BCS + quasip...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Physical review letters
دوره 106 25 شماره
صفحات -
تاریخ انتشار 2011