Decays of ${}^{39}{Ca}$ and ${}^{41}{Sc}$

The decays of

{}^{39}{Ca}

and

{}^{41}{Sc}

have been studied because of the related interest in the magnitude of the axial coupling constant in nuclear matter.

{}^{39}{Ca}

was produced in the

{}^{39}K (p, n) {}^{39}{Ca}

reaction at

E_{p} = 10

MeV and its half-life was measured as 860.4 ± 3.0 msec resulting in an

ft

value of 4283 ± 25 sec. The half-life of

{}^{41}{Sc}

, formed in the

{}^{40}{Ca} (p, γ) {}^{41}{Sc}

reaction with 3-MeV protons on thick Ca, is 596.3 ± 1.7 msec. From the

γ

-ray energies of 2882.6 ± 0.3 keV and 3696.9 ± 0.5 keV measured at the 1.84- and 2.68-MeV resonances the

Q

value of the

{}^{40}{Ca} (p, γ) {}^{41}{Sc}

reaction is found to be 1085.7 ± 1.4 keV. This leads to a

{}^{41}{Sc}

mass excess of -28 642.2 ± 1.7 keV, to a

{}^{41}{Sc}

decay energy of 6494.9 ± 2.0 keV, and to an

ft

value of 2849 ± 9 sec. An upper limit of 2×

10^{- 3}

is placed on the

β

branching of

{}^{41}{Sc}

to excited states of

{}^{41}{Ca}

. If the free-space value of

g_{A}

is used to extract the Gamow-Teller matrix element

{〈 σ 〉}_{\exp}

from these data we find

\frac{{〈 σ 〉}_{\exp}}{{〈 σ 〉}_{s . p .}}

values of 0.685 ± 0.009 and 0.761 ± 0.006 for

{}^{39}{Ca}

and

{}^{41}{Sc}

, respectively, where the

{〈 σ 〉}_{s . p .}

are the relevant single-particle matrix elements.

This publication has 10 references indexed in Scilit:

Decays ofCa39andSc41