Lifetime of 26S and a Limit for its 2p Decay Energy

A. S. Fomichev; I. G. Mukha; S. V. Stepantsov; L. V. Grigorenko; E. V. Litvinova; V. Chudoba; I. A. Egorova; M. S. Golovkov; A. V. Gorshkov; V. A. Gorshkov; G. Kaminski; S. A. Krupko; Y. L. Parfenova; S. I. Sidorchuk; R. S. Slepnev; G. M. Ter-Akopian; R. Wolski; Mikhail Zhukov

doi:10.1142/s0218301311018216

Lifetime of 26S and a Limit for its 2p Decay Energy
Artikel i vetenskaplig tidskrift, 2011

The unknown isotope (26)S, expected to decay by two-proton (2p) emission, was studied theoretically and searched experimentally. The structure of this nucleus was examined within the relativistic mean field (RMF) approach. A method for taking into account the many-body structure in the three-body decay calculations was developed. The results of the RMF calculations were used as an input for the three-cluster decay model optimized for the study of a possible 2p decay branch of this nucleus. The experimental search for (26)S was performed by fragmentation of a 50.3 A MeV (32)S beam. No events of a particles table (26)S or (25)P (a presumably proton-unstable subsystem of (26)S) were observed. Based on the obtained production systematics, an upper half-life limit of T(1/2) < 79 ns was established from the time-of-flight through the fragment separator. Together with the theoretical lifetime estimates for two-proton decay, this gives a decay energy limit of Q(2p) > 640 keV for (26)S. Analogous limits for (25)P are found as T(1/2) < 38 ns and Q(p) > 110 keV. In the case that the one-proton emission is the main branch of the (26)S decay, a limit Q(2p) > 230 keV would follow for this nucleus. According to these limits, it is likely that (26)S resides in the picosecond life time range

Properties of nuclei

nuclear energy

shell

drip lines

light-nuclei

2-proton decay

proton

be-6

fe-45

halos

neutron

radioactivity

mean-field-theory