21+ to 31+ γ width in Na 22 and second class currents 21+ to 31+ γ WIDTH in Na 22 ⋯ S. TRIAMBAK et al.

S. Triambak, L. Phuthu, A. García, G. C. Harper, J. N. Orce, D. A. Short, S. P R Steininger, A. Diaz Varela, R. Dunlop, D. S. Jamieson, W. A. Richter, G. C. Ball, P. E. Garrett, C. E. Svensson, C. Wrede

    Research output: Contribution to journalArticle

    Abstract

    Background: A previous measurement of the β-γ directional coefficient in Na22β decay was used to extract recoil-order form factors. The data indicate the requirement of a significant induced-tensor matrix element for the decay. This conclusion largely relies on a standard-model-allowed weak magnetism form factor which was determined using an unpublished value of the analog 21+→31+ γ branch in Na22, with the further assumption that the transition is dominated by its isovector M1 component. Purpose: Our aim is to determine the 21+→31+ width in Na22 in order to obtain an independent measurement of the weak magnetism form factor for the β decay. Methods: A Ne21(p,γ) resonance reaction on an implanted target was used to produce the first 2+ state in Na22 at Ex=1952 keV. Deexcitation γ rays were registered with two 100% relative efficiency high purity germanium detectors. Results: We obtain for the first time an unambiguous determination of the 21+→31+ branch in Na22 to be 0.45(8)%. Conclusions: Using the conserved vector current (CVC) hypothesis, our branch determines the weak magnetism form factor for Na22β decay to be |b/Ac1|=8.7(1.1). Together with the β-γ angular correlation coefficient, we obtain a large induced-tensor form factor for the decay that continues to disagree with theoretical predictions. Two plausible explanations are suggested.

    Original languageEnglish (US)
    Article number035501
    JournalPhysical Review C
    Volume95
    Issue number3
    DOIs
    StatePublished - Mar 15 2017

    Profile

    form factors
    decay
    tensors
    vector currents
    angular correlation
    correlation coefficients
    germanium
    purity
    gamma rays
    analogs
    requirements
    detectors
    coefficients
    matrices
    predictions

    ASJC Scopus subject areas

    • Nuclear and High Energy Physics

    Cite this

    Triambak, S., Phuthu, L., García, A., Harper, G. C., Orce, J. N., Short, D. A., ... Wrede, C. (2017). 21+ to 31+ γ width in Na 22 and second class currents 21+ to 31+ γ WIDTH in Na 22 ⋯ S. TRIAMBAK et al. Physical Review C, 95(3), [035501]. DOI: 10.1103/PhysRevC.95.035501

    21+ to 31+ γ width in Na 22 and second class currents 21+ to 31+ γ WIDTH in Na 22 ⋯ S. TRIAMBAK et al. / Triambak, S.; Phuthu, L.; García, A.; Harper, G. C.; Orce, J. N.; Short, D. A.; Steininger, S. P R; Diaz Varela, A.; Dunlop, R.; Jamieson, D. S.; Richter, W. A.; Ball, G. C.; Garrett, P. E.; Svensson, C. E.; Wrede, C.

    In: Physical Review C, Vol. 95, No. 3, 035501, 15.03.2017.

    Research output: Contribution to journalArticle

    Triambak, S, Phuthu, L, García, A, Harper, GC, Orce, JN, Short, DA, Steininger, SPR, Diaz Varela, A, Dunlop, R, Jamieson, DS, Richter, WA, Ball, GC, Garrett, PE, Svensson, CE & Wrede, C 2017, '21+ to 31+ γ width in Na 22 and second class currents 21+ to 31+ γ WIDTH in Na 22 ⋯ S. TRIAMBAK et al.' Physical Review C, vol 95, no. 3, 035501. DOI: 10.1103/PhysRevC.95.035501
    Triambak S, Phuthu L, García A, Harper GC, Orce JN, Short DA et al. 21+ to 31+ γ width in Na 22 and second class currents 21+ to 31+ γ WIDTH in Na 22 ⋯ S. TRIAMBAK et al. Physical Review C. 2017 Mar 15;95(3). 035501. Available from, DOI: 10.1103/PhysRevC.95.035501

    Triambak, S.; Phuthu, L.; García, A.; Harper, G. C.; Orce, J. N.; Short, D. A.; Steininger, S. P R; Diaz Varela, A.; Dunlop, R.; Jamieson, D. S.; Richter, W. A.; Ball, G. C.; Garrett, P. E.; Svensson, C. E.; Wrede, C. / 21+ to 31+ γ width in Na 22 and second class currents 21+ to 31+ γ WIDTH in Na 22 ⋯ S. TRIAMBAK et al.

    In: Physical Review C, Vol. 95, No. 3, 035501, 15.03.2017.

    Research output: Contribution to journalArticle

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    abstract = "Background: A previous measurement of the β-γ directional coefficient in Na22β decay was used to extract recoil-order form factors. The data indicate the requirement of a significant induced-tensor matrix element for the decay. This conclusion largely relies on a standard-model-allowed weak magnetism form factor which was determined using an unpublished value of the analog 21+→31+ γ branch in Na22, with the further assumption that the transition is dominated by its isovector M1 component. Purpose: Our aim is to determine the 21+→31+ width in Na22 in order to obtain an independent measurement of the weak magnetism form factor for the β decay. Methods: A Ne21(p,γ) resonance reaction on an implanted target was used to produce the first 2+ state in Na22 at Ex=1952 keV. Deexcitation γ rays were registered with two 100% relative efficiency high purity germanium detectors. Results: We obtain for the first time an unambiguous determination of the 21+→31+ branch in Na22 to be 0.45(8)%. Conclusions: Using the conserved vector current (CVC) hypothesis, our branch determines the weak magnetism form factor for Na22β decay to be |b/Ac1|=8.7(1.1). Together with the β-γ angular correlation coefficient, we obtain a large induced-tensor form factor for the decay that continues to disagree with theoretical predictions. Two plausible explanations are suggested.",
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    AU - García,A.

    AU - Harper,G. C.

    AU - Orce,J. N.

    AU - Short,D. A.

    AU - Steininger,S. P R

    AU - Diaz Varela,A.

    AU - Dunlop,R.

    AU - Jamieson,D. S.

    AU - Richter,W. A.

    AU - Ball,G. C.

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    N2 - Background: A previous measurement of the β-γ directional coefficient in Na22β decay was used to extract recoil-order form factors. The data indicate the requirement of a significant induced-tensor matrix element for the decay. This conclusion largely relies on a standard-model-allowed weak magnetism form factor which was determined using an unpublished value of the analog 21+→31+ γ branch in Na22, with the further assumption that the transition is dominated by its isovector M1 component. Purpose: Our aim is to determine the 21+→31+ width in Na22 in order to obtain an independent measurement of the weak magnetism form factor for the β decay. Methods: A Ne21(p,γ) resonance reaction on an implanted target was used to produce the first 2+ state in Na22 at Ex=1952 keV. Deexcitation γ rays were registered with two 100% relative efficiency high purity germanium detectors. Results: We obtain for the first time an unambiguous determination of the 21+→31+ branch in Na22 to be 0.45(8)%. Conclusions: Using the conserved vector current (CVC) hypothesis, our branch determines the weak magnetism form factor for Na22β decay to be |b/Ac1|=8.7(1.1). Together with the β-γ angular correlation coefficient, we obtain a large induced-tensor form factor for the decay that continues to disagree with theoretical predictions. Two plausible explanations are suggested.

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