β-spectroscopy of 11Li and 14Be —With a β-n-γ triple coincidence method

Aoi, N.; Yoneda, K.; Miyatake, H.; Ogawa, Hiroshi; Yamamoto, Yukio; Ideguchi, E.; Kishida, T.; Nakamura, Takashi; Notani, M.; Sakuraï, H.; Teranishi, Takashi; Wu, Haiqing; Yamamoto, S. S.; Watanabe, Yutaka; Yoshida, Akihiro; Ishihara, M.

doi:10.1016/s0375-9474(97)00087-0

Cited by 64 publications

(66 citation statements)

References 13 publications

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“…The reports of Hirayama et al [1], Aoi et al [5], and Morrissey et al [6] from β-decay of 11 Li, noted excited states in 11 Be including (1.778 MeV)(J π = 5/2 + ), (2.690 MeV)(J π = 3/2 − ), and (3.949 MeV)(J π = 3/2 − ) that are also observed in this work. Additionally, Navin et al [3] demonstrated the importance of sd intruder states to understanding the structure of 11 Be by using neutron-knockout reactions from 12 Be to populate the 1/2 + and the 1/2 − states in 11 Be.…”

supporting

confidence: 84%

Neutron knockout ofBe12populating neutron-unbound states inBe11
Peters
¹
,
Baumann
²
,
Brown
³

et al. 2011
Phys. Rev. C
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supporting

confidence: 84%

Neutron knockout ofBe12populating neutron-unbound states inBe11
Peters
¹
,
Baumann
²
,
Brown
³

et al. 2011
Phys. Rev. C
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2
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“…[48,49]. For the N 2 LO SAT interaction the resonance energy is close to the one predicted by the Gamow shell model [50], although our ab initio calculations predict a broader width.…”

supporting

confidence: 76%

CanAb InitioTheory Explain the Phenomenon of Parity Inversion inBe11?

et al. 2016

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The weakly bound exotic 11 Be nucleus, famous for its ground-state parity inversion and distinct n+ 10 Be halo structure, is investigated from first principles using chiral two-and three-nucleon forces. An explicit treatment of continuum effects is found to be indispensable. We study the sensitivity of the 11 Be spectrum to the details of the three-nucleon force and demonstrate that only certain chiral interactions are capable of reproducing the parity inversion. With such interactions, the extremely large E1 transition between the bound states is reproduced. We compare our photodisintegration calculations to conflicting experimental data and predict a distinct dip around the 3/2 − 1 resonance energy. Finally, we predict low-lying 3/2 + and 9/2 + resonances that are not or not sufficiently measured in experiments.The theoretical understanding of exotic neutron-rich nuclei constitutes a tremendous challenge. These systems often cannot be explained by mean-field approaches and contradict the regular shell structure. The spectrum of 11 Be has some very peculiar features. The 1/2 + ground state (g.s.) is loosely bound by 502 keV with respect to the n+ 10 Be threshold and is separated by only 320 keV from its parity-inverted 1/2 − partner [1, 2], which would be the expected g.s. in the standard shell-model picture. Such parity inversion, already noticed by Talmi and Unna [3] in the early 1960s, is one of the best examples of the disappearance of the N = 8 magic number with an increasing neutron to proton ratio. The next (n+n+ 9 Be) breakup threshold appears at 7.31 MeV [4], such that the rich resonance structure at low energies is dominated by the n+ 10 Be dynamics. Peculiar also is the electricdipole transition strength between the two bound states, which has attracted much attention since its first measurement in 1971 [5] and was remeasured in 1983 [6] and 2014 [7]. It is the strongest known transition between low-lying states, attributed to the halo character of 11 Be.An accurate description of this complex spectrum is anticipated to be sensitive to the details of the nuclear force [8], such that a precise knowledge of the nucleon-nucleon (NN) interaction, desirably obtained from first principles, is crucial. Moreover, the inclusion of three-nucleon (3N) effects has been found to be indispensable for an accurate description of nuclear systems [9,10]. The chiral effective field theory constitutes one of the most promising candidates for deriving the nuclear interaction. Formulated by Weinberg [11][12][13], it is based on the fundamental symmetries of QCD and uses pions and nucleons as relevant degrees of freedom. Within this theory NN, 3N and higher many-body interactions arise in a natural hierarchy [11][12][13][14][15][16][17]. The details of these interactions depend on the specific choices made during the construction. In particular the way the interactions are constrained to experimental data can have a strong impact [18].In this work we tackle the question if ab initio calculations can provide an accurate des...

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“…The levels and decay scheme of 11 Be have previously been studied through measurements of the β-delayed neutron emission of 11 Li [21][22][23][24][25][26][27]. Where available, the branching ratios are compared with these measurements.…”

Section: Introductionmentioning

confidence: 99%

Neutron decay widths of excited states ofBe11

et al. 2009

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The two-neutron transfer reaction 9 Be( 16 O, 14 O) 11 Be[ 10 Be + n] has been used to measure the branching ratios for the neutron decay of excited states of 11 Be. The 14 O ejectile was detected by a Q3D spectrometer at forward angles. The energies and angles of the 10 Be fragments of the decaying 11 Be * recoil were measured in coincidence with the 14 O ejectile using a double-sided silicon strip detector array at backward angles. This enabled a kinematic reconstruction of the reaction to be performed. Theoretical decay branch ratios were calculated using barrier penetrability factors and were compared to the measured ratios to provide information on the relative reduced widths of the states. The decay widths have been used to link states in 11 Be with a common structure and structurally to states in the daughter nucleus 10 Be. The 3/2 − 8.82-MeV state was identified as a candidate for a molecular band head.

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β-spectroscopy of 11Li and 14Be —With a β-n-γ triple coincidence method

Cited by 64 publications

References 13 publications

Neutron knockout ofBe12populating neutron-unbound states inBe11
Peters
¹
,
Baumann
²
,
Brown
³

et al. 2011
Phys. Rev. C
Self Cite
15
2
19
2
View full text Add to dashboard Cite

Neutron knockout ofBe12populating neutron-unbound states inBe11
Peters
¹
,
Baumann
²
,
Brown
³

et al. 2011
Phys. Rev. C
Self Cite
15
2
19
2
View full text Add to dashboard Cite

CanAb InitioTheory Explain the Phenomenon of Parity Inversion inBe11?

Neutron decay widths of excited states ofBe11

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β-spectroscopy of 11Li and 14Be —With a β-n-γ triple coincidence method

Cited by 64 publications

References 13 publications

Neutron knockout ofBe12populating neutron-unbound states inBe11Peters1, Baumann2, Brown3 et al. 2011Phys. Rev. CSelf Cite152192View full textAdd to dashboardCite

Neutron knockout ofBe12populating neutron-unbound states inBe11Peters1, Baumann2, Brown3 et al. 2011Phys. Rev. CSelf Cite152192View full textAdd to dashboardCite

CanAb InitioTheory Explain the Phenomenon of Parity Inversion inBe11?

Neutron decay widths of excited states ofBe11

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About

Neutron knockout ofBe12populating neutron-unbound states inBe11
Peters
¹
,
Baumann
²
,
Brown
³

et al. 2011
Phys. Rev. C
Self Cite
15
2
19
2
View full text Add to dashboard Cite

Neutron knockout ofBe12populating neutron-unbound states inBe11
Peters
¹
,
Baumann
²
,
Brown
³

et al. 2011
Phys. Rev. C
Self Cite
15
2
19
2
View full text Add to dashboard Cite