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

be-6

light-nuclei

proton

halos

drip lines

fe-45

2-proton decay

neutron

shell

radioactivity

nuclear energy

mean-field-theory

Författare

A. S. Fomichev

Joint Institute for Nuclear Research

I. G. Mukha

Universitat de Valencia

S. V. Stepantsov

Joint Institute for Nuclear Research

L. V. Grigorenko

National Research Centre "Kurchatov Institute"

Joint Institute for Nuclear Research

E. V. Litvinova

Johann Wolfgang Goethe Universität Frankfurt am Main

V. Chudoba

Joint Institute for Nuclear Research

Slezska univerzita v Opave

I. A. Egorova

Joint Institute for Nuclear Research

M. S. Golovkov

Joint Institute for Nuclear Research

A. V. Gorshkov

Joint Institute for Nuclear Research

V. A. Gorshkov

Joint Institute for Nuclear Research

G. Kaminski

Moscow State University

Joint Institute for Nuclear Research

S. A. Krupko

Joint Institute for Nuclear Research

Y. L. Parfenova

Joint Institute for Nuclear Research

Moscow State University

S. I. Sidorchuk

Joint Institute for Nuclear Research

R. S. Slepnev

Joint Institute for Nuclear Research

G. M. Ter-Akopian

Joint Institute for Nuclear Research

R. Wolski

Henryk Niewodniczanski Institute of Nuclear Physics of the Polish Academy of Sciences

Joint Institute for Nuclear Research

Mikhail Zhukov

Chalmers, Teknisk fysik, Subatomär fysik

International Journal of Modern Physics E

0218-3013 (ISSN)

Vol. 20 6 1491-1508

Ämneskategorier

Fysik

DOI

10.1142/s0218301311018216