Retention Capacity of Random Surfaces

Knecht, Craig L.; Trump, Walter; ben‐Avraham, Daniel; Ziff, Robert M.

doi:10.1103/physrevlett.108.045703

Cited by 33 publications

(67 citation statements)

References 9 publications

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“…For comparison, the experimental splitting is 2.55MeV [21]. Recently, Knecht et al [22] performed high-precision measurement of the 0 + →1 + beta decay of 6 He, which proceeds exclusively to the ground state (GS) of 6 Li and determined the corresponding GT matrix element |M GT |=2.1645(43) assuming g A =-1.2701 (25). This is an excellent test case for our model mainly because of a limited number of ph configurations that can contribute in these p-shell nuclei.…”

Section: (Eff)mentioning

confidence: 99%

β-decay study within multireference density functional theory and beyond

2016

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Pioneering study of Gamow-Teller (GT) and Fermi matrix elements (MEs) using no-coreconfiguration-interaction formalism rooted in multi-reference density functional theory is presented. After successful test performed for 6 He→ 6 Li β-decay, the model is applied to compute MEs in the sd-and pf -shell T =1/2 mirror nuclei. The calculated GT MEs and the isospin-symmetry-breaking corrections to the Fermi branch are found to be in a very good agreement with shell-model predictions in spite of fundamental differences between these models concerning model space, treatment of correlations or inclusion of a core. This result indirectly supports the two-body current based scenarios behind the quenching of axial-vector coupling constant.PACS numbers: 21.10. Hw, 21.60.Jz, 21.30.Fe, 23.40.Hc, 24.80.+y The atomic nuclei are unique laboratories to study fundamental processes and search for possible signals of new physics beyond the Standard Model in ways that are complementary or even superior to other sciences. This is due to enhanced sensitivity of specific isotopes to fundamental symmetries caused, in particular, by intrinsic-symmetry-related or purely accidental (near-)degeneracies of nuclear states. For example, parity doublets caused by stable octupole deformation increase sensitivity to search for the violation of CP-symmetry which is responsible for matter over anti-matter dominated Universe [1]. Accidental near-degeneracy of 3/2 + and 5/2 + levels in 229 Th, which are separated only by 7.6±0.5 eV, opens up a possibility for high-precision measurement of the temporal variation of fine-structure constant with much higher sensitivity as compared to the atomic transitions [2]. Last but not least, nuclear physics input is critical in an ongoing hunt for a weakly-interacting massive particle (WIMP), a candidate for dark matter, in direct detection experiments measuring the recoil energy deposited when WIMP is scattered off the nucleus, see [3] and refs. quoted therein.Traditionally, the atomic nuclei are used to study the weak interaction. A flagship example is the superallowed I=0 + →I=0 + β-decay among the members of the isobaric triplets T =1. With small, of order of a percent, theoretical corrections accounting for radiative processes and isospin symmetry breaking (ISB), these semileptonic pure Fermi (vector) decays allow to verify the conserved vector current (CVC) hypothesis with a very high precision. In turn, they provide the most precise values of the strength of the weak force, G F , and of the leading element, V ud , of the Cabbibo-Kobayashi-Maskawa (CKM) matrix, see [4] for a recent review.The T =1/2 mirror nuclei offer an alternative way to test the CVC hypothesis [5]. These nuclei decay via the mixed Fermi and Gamow-Teller (GT) transitions. Hence, apart from the radiative and the ISB theoretical corrections, the final values of G F and V ud depend on the ratio of statistical rate functions for the axial-vector and vector interactions, f A /f V , and the ratio of nuclear matrix elements ρ ≈ λM GT /M F where ...

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Section: (Eff)mentioning

confidence: 99%

β-decay study within multireference density functional theory and beyond

2016

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“…This nucleus is of Borromean nature, where the twoneutron and neutron-core subsystems are unbound, but the three-body system is held together [2]. 6 He is a radioactive nucleus that undergoes β-decay with a half-life of 0.8 s [3]. Despite this short life-time, a combination of nuclear and atomic physics techniques recently enabled a series of precision measurements of 6 He.…”

Section: Introductionmentioning

confidence: 99%

Matter and charge radius of6He in the hyperspherical-harmonics approach

2012

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We present ab-initio calculations of the binding energy and radii of the two-neutron halo nucleus 6 He using two-body low-momentum interactions based on chiral effective field theory potentials. Calculations are performed via a hyperspherical harmonics expansion where the convergence is sped up introducing an effective interaction for non-local potentials. The latter is essential to reach a satisfactory convergence of the extended matter radius and of the point-proton radius. The dependence of the results on the resolution scale is studied. A correlation is found between the radii and the two-neutron separation energy. The importance of three-nucleon forces is pointed out comparing our results and previous calculations to experiment.

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“…In this paper we present a more detailed description of the high-precision experimental determination of the half-life and f t-value for 6 He published in [16]. Except for a small branch of ∼10 −6 [17] the beta decay of 6 He proceeds 100% to the ground state of 6 Li with an endpoint of 3.5 MeV.…”

Section: Introductionmentioning

confidence: 99%

Precision measurement of the6He half-life and the weak axial current in nuclei

et al. 2012

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Background: The beta decays of 3 H and 6 He can play an important role in testing nuclear wave-function calculations and fixing low-energy constants in effective-field theory approaches. However, there exists a large discrepancy between previous measurements of the 6 He half-life.Purpose: Our measurement aims at resolving this long-standing discrepancy in the 6 He half-life and providing a reliable f t-value and Gamow-Teller matrix element for comparison with theoretical ab-initio calculations.Method: We measured the 6 He half-life by counting the beta-decay electrons with two scintillator detectors operating in coincidence.Results: The measured 6 He half-life is 806.89 ± 0.11stat +0.23 −0.19 syst ms corresponding to a relative precision of 3 × 10 −4 . Calculating the statistical rate function we determined the f t-value to be 803.04 +0.26 −0.23 s. Conclusions: Our result resolves the previous discrepancy by providing a higher-precision result with careful analysis of potential systematic uncertainties. The result provides a reliable basis for future precision comparisons with ab-inito calculations.

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Retention Capacity of Random Surfaces

Cited by 33 publications

References 9 publications

β-decay study within multireference density functional theory and beyond

β-decay study within multireference density functional theory and beyond

Matter and charge radius of6He in the hyperspherical-harmonics approach

Precision measurement of the6He half-life and the weak axial current in nuclei

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