Abstract
The magnetic moments of 17N and 17B were measured by using spin-polarized radioactive nuclear beams which were obtained from the projectile fragmentation reaction. The observed magnetic moment of 17N, |μ(17N)|=(0.352±0.002)μN, where μN is the nuclear magneton, falls outside the Schmidt lines. By virtue of a simplifying feature of nuclear structure inherent in a p1/2 valence nucleus, the deviation from the Schmidt value is attributed on firm ground to admixing of the configurations in which two neutrons in the sd shell are coupled to Jπ=2+. This interpretation is confirmed in standard shell-model calculations. The calculations reproduce fairly well the experimentally inferred amount of 2+ admixture, as well as the experimental magnetic moment itself. The magnetic moment for 17B was determined as |μ(17B)|=(2.545±0.020)μN. The result is substantially smaller than the πp1/2 single-particle value, and the shell-model calculations indicate that the quenching of μ largely stems from Jπ=2+ configurations of the sd neutrons. The observed amount of quenching, however, is larger than the shell-model predictions, suggesting an enhanced contribution of the 2+ neutron configurations. This result is explained if the pairing energy for neutrons in the sd shell of a neutron-rich nucleus is assumed to diminish by about 30%. We also find that the use of the reduced pairing energy improves agreements in the magnetic moment and low-lying energy levels of 17N as well.
| Original language | English |
|---|---|
| Pages (from-to) | 2142-2151 |
| Number of pages | 10 |
| Journal | Physical Review C - Nuclear Physics |
| Volume | 53 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - May 1996 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Physics and Astronomy(all)
- Nuclear and High Energy Physics
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Magnetic moments of 17N and 17B. / Ueno, H.; Asahi, K.; Izumi, H.; Nagata, K.; Ogawa, H.; Yoshimi, Akihiro; Sato, H.; Adachi, M.; Hori, Y.; Mochinaga, K.; Okuno, H.; Aoi, N.; Ishihara, M.; Yoshida, A.; Liu, G.; Kubo, T.; Fukunishi, N.; Shimoda, T.; Miyatake, H.; Sasaki, M.; Shirakura, T.; Takahashi, N.; Mitsuoka, S.; Schmidt-Ott, W. D.
In: Physical Review C - Nuclear Physics, Vol. 53, No. 5, 05.1996, p. 2142-2151.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Magnetic moments of 17N and 17B
AU - Ueno, H.
AU - Asahi, K.
AU - Izumi, H.
AU - Nagata, K.
AU - Ogawa, H.
AU - Yoshimi, Akihiro
AU - Sato, H.
AU - Adachi, M.
AU - Hori, Y.
AU - Mochinaga, K.
AU - Okuno, H.
AU - Aoi, N.
AU - Ishihara, M.
AU - Yoshida, A.
AU - Liu, G.
AU - Kubo, T.
AU - Fukunishi, N.
AU - Shimoda, T.
AU - Miyatake, H.
AU - Sasaki, M.
AU - Shirakura, T.
AU - Takahashi, N.
AU - Mitsuoka, S.
AU - Schmidt-Ott, W. D.
PY - 1996/5
Y1 - 1996/5
N2 - The magnetic moments of 17N and 17B were measured by using spin-polarized radioactive nuclear beams which were obtained from the projectile fragmentation reaction. The observed magnetic moment of 17N, |μ(17N)|=(0.352±0.002)μN, where μN is the nuclear magneton, falls outside the Schmidt lines. By virtue of a simplifying feature of nuclear structure inherent in a p1/2 valence nucleus, the deviation from the Schmidt value is attributed on firm ground to admixing of the configurations in which two neutrons in the sd shell are coupled to Jπ=2+. This interpretation is confirmed in standard shell-model calculations. The calculations reproduce fairly well the experimentally inferred amount of 2+ admixture, as well as the experimental magnetic moment itself. The magnetic moment for 17B was determined as |μ(17B)|=(2.545±0.020)μN. The result is substantially smaller than the πp1/2 single-particle value, and the shell-model calculations indicate that the quenching of μ largely stems from Jπ=2+ configurations of the sd neutrons. The observed amount of quenching, however, is larger than the shell-model predictions, suggesting an enhanced contribution of the 2+ neutron configurations. This result is explained if the pairing energy for neutrons in the sd shell of a neutron-rich nucleus is assumed to diminish by about 30%. We also find that the use of the reduced pairing energy improves agreements in the magnetic moment and low-lying energy levels of 17N as well.
AB - The magnetic moments of 17N and 17B were measured by using spin-polarized radioactive nuclear beams which were obtained from the projectile fragmentation reaction. The observed magnetic moment of 17N, |μ(17N)|=(0.352±0.002)μN, where μN is the nuclear magneton, falls outside the Schmidt lines. By virtue of a simplifying feature of nuclear structure inherent in a p1/2 valence nucleus, the deviation from the Schmidt value is attributed on firm ground to admixing of the configurations in which two neutrons in the sd shell are coupled to Jπ=2+. This interpretation is confirmed in standard shell-model calculations. The calculations reproduce fairly well the experimentally inferred amount of 2+ admixture, as well as the experimental magnetic moment itself. The magnetic moment for 17B was determined as |μ(17B)|=(2.545±0.020)μN. The result is substantially smaller than the πp1/2 single-particle value, and the shell-model calculations indicate that the quenching of μ largely stems from Jπ=2+ configurations of the sd neutrons. The observed amount of quenching, however, is larger than the shell-model predictions, suggesting an enhanced contribution of the 2+ neutron configurations. This result is explained if the pairing energy for neutrons in the sd shell of a neutron-rich nucleus is assumed to diminish by about 30%. We also find that the use of the reduced pairing energy improves agreements in the magnetic moment and low-lying energy levels of 17N as well.
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U2 - 10.1103/PhysRevC.53.2142
DO - 10.1103/PhysRevC.53.2142
M3 - Article
AN - SCOPUS:0030532556
VL - 53
SP - 2142
EP - 2151
JO - Physical Review C - Nuclear Physics
JF - Physical Review C - Nuclear Physics
SN - 0556-2813
IS - 5
ER -