Gamow-Teller strength distributions in 48Sc by the 48Ca(p,n) and 48Ti(n,p) reactions and two-neutrino double-beta decay nuclear matrix elements.
The double-differential cross sections for the 48Ca(p,n) and 48Ti(n,p) reactions were measured at 300 MeV. A multipole decomposition technique was applied to the spectra to extract the Gamow-Teller (GT) components. The integrated GT strengths up to an excitation energy of 30 MeV in 48Sc are 15.3+/-2.2 and 2.8+/-0.3 in the (p,n) and (n,p) spectra, respectively. In the (n,p) spectra additional GT strengths were found above 8 MeV where shell models within the fp shell-model space predict almost no GT strengths, suggesting that the present shell-model description of the nuclear matrix element of the two-neutrino double-beta decay is incomplete.
Yako
K
K
Department of Physics, University of Tokyo, Bunkyo, Tokyo 113-0033, Japan.
Sasano
M
M
Miki
K
K
Sakai
H
H
Dozono
M
M
Frekers
D
D
Greenfield
M B
MB
Hatanaka
K
K
Ihara
E
E
Kato
M
M
Kawabata
T
T
Kuboki
H
H
Maeda
Y
Y
Matsubara
H
H
Muto
K
K
Noji
S
S
Okamura
H
H
Okabe
T H
TH
Sakaguchi
S
S
Sakemi
Y
Y
Sasamoto
Y
Y
Sekiguchi
K
K
Shimizu
Y
Y
Suda
K
K
Tameshige
Y
Y
Tamii
A
A
Uesaka
T
T
Wakasa
T
T
Zheng
H
H