Energy levels of light nuclei, A = 20

Tilley, D. R.; Cheves, C. M.; Kelley, J. H.; Raman, S.; Weller, H. R.

doi:10.1016/s0375-9474(98)00129-8

Cited by 245 publications

(309 citation statements)

References 573 publications

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“…This conclusion disagrees with the older measurement [20], where the existence of two resonances with J π =1 − and 0 + had been reported at E cm ∼0.4 MeV. Actually, additional resonances might be populated in 20 Ne [32]. A recent experiment [33] measured the 19 F(p,α 0 ) 16 O astrophysical S (E)-factor by indirect means of the Trojan Horse method, and found that the largest rate difference, about 70%, occurs at temperatures relevant for post-AGB stars (∼0.1 GK), exceeding the upper limit set by the previous uncertainties [28].…”

Section: (Pα 0 ) Channelcontrasting

confidence: 96%

A proposed direct measurement of cross section at Gamow window for key reaction 19F(p,α) 16O in Asymptotic Giant Branch stars with a planned accelerator in CJPL

et al. 2016

Sci. China Phys. Mech. Astron.

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In 2014, the National Natural Science Foundation of China (NSFC) approved the Jinping Underground Nuclear Astrophysics laboratory (JUNA) project, which aims at direct cross-section measurements of four key stellar nuclear reactions right down to the Gamow windows. In order to solve the observed fluorine overabundances in Asymptotic Giant Branch (AGB) stars, measuring the key 19 F(p,α) 16 O reaction at effective burning energies (i.e., at Gamow window) is established as one of the scientific research sub-projects. The present paper describes this sub-project in details, including motivation, status, experimental setup, yield and background estimation, aboveground test, as well as other relevant reactions.Jinping Underground Nuclear Astrophysics laboratory (JUNA), direct measurement, Gamow window, cross section, AGB star, nucleosynthesis PACS number(s): 26.20.+f; 26.30.+k; 25.40.Ny, 27.20+n Citation:He J J, et al. A proposed direct measurement of cross section at Gamow window for key reaction 19 F(p,α) 16 O in Asymptotic Giant Branch stars with a planned accelerator in CJPL, Sci China-Phys Mech Astron, 2015, 58: 1-7, doi:

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Section: (Pα 0 ) Channelcontrasting

confidence: 96%

A proposed direct measurement of cross section at Gamow window for key reaction 19F(p,α) 16O in Asymptotic Giant Branch stars with a planned accelerator in CJPL

et al. 2016

Sci. China Phys. Mech. Astron.

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“…The accelerator-energy calibration in the BE1 experiment was determined by measuring the 19 F(p,αγ) 16 O resonances at 340.46 ± 0.04, 483.91 ±0.10 and 872.11 ± 0.20 keV [36] using a thick LiF target. The measured thick-target yield curves were fitted with the integral of a Lorentzian folded with a Gaussian beam energy resolution.…”

Section: Beam-energy Calibrationmentioning

confidence: 99%

Precise measurement of theBe7(p,γ)B8
Junghans
¹
,
Mohrmann
²
,
Snover
³

et al. 2003
Phys. Rev. C
140
34
279
4
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We present new measurements of the 7 Be(p,γ) 8 B cross section fromĒcm = 116 to 2460 keV, that incorporate several improvements over our previously published experiment, also discussed here. Our new measurements lead to S17(0) = 22.1 ± 0.6(expt) ± 0.6(theor) eV b based on data from Ecm = 116 to 362 keV, where the central value is based on the theory of Descouvemont and Baye. The theoretical error estimate is based on the fit of 12 different theories to our low energy data. We compare our results to other S17(0) values extracted from both direct ( 7 Be(p,γ) 8 B) and indirect (Coulomb dissociation and heavy-ion reaction) measurements, and show that the results of these 3 types of experiments are not mutually compatible. We recommend a "best" value, S17(0) = 21.4 ± 0.5(expt) ± 0.6(theor) eV b, based on the mean of all modern direct measurements below the 1 + resonance. We also present S-factors at 20 keV which is near the center of the Gamow window: the result of our measurements is S17(20) = 21.4 ± 0.6(expt) ± 0.6(theor) eV b, and the recommended value is S17(20) = 20.7 ± 0.5(expt) ± 0.6(theor) eV b.PACS numbers: 26.20+f, 26.65+t, 25.40Lw

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“…with τ the lifetime taken from literature [12]. The normalization relative to 2τ instead off τ − +τ + is done to avoid dependence on common systematic errors.…”

Section: Principle Of the Measurementmentioning

confidence: 99%

Test of Lorentz invariance inβdecay of polarizedNa20

Sytema¹,

Berg

Böll

et al. 2016

Phys. Rev. C

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Background: Lorentz invariance is key in our understanding of nature, yet relatively few experiments have tested Lorentz invariance in weak interactions.Purpose: Obtaining limits on Lorentz-invariance violation in weak interactions, in particular rotational invariance in β-decay. Method:We search for a dependence of the lifetime of 20 Na nuclei on the nuclear spin direction.Such directional dependence would be evidence for Lorentz-invariance violation in weak interactions. A difference in lifetime between nuclei that are polarized in the east and west direction is searched for. This difference is maximally sensitive to the rotation of the Earth, while the sidereal dependence is free from most systematic errors.Results: The experiment sets a limit of 2 × 10 −4 at 90 % C.L. on the amplitude of the sidereal variation of the relative lifetime differences, an improvement by a factor 15 compared to an earlier result.Conclusions: No significant violation of Lorentz invariance is found. The result sets limits on parameters of theories describing Lorentz-invariance violation.

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Energy levels of light nuclei, A = 20

Cited by 245 publications

References 573 publications

A proposed direct measurement of cross section at Gamow window for key reaction 19F(p,α) 16O in Asymptotic Giant Branch stars with a planned accelerator in CJPL

A proposed direct measurement of cross section at Gamow window for key reaction 19F(p,α) 16O in Asymptotic Giant Branch stars with a planned accelerator in CJPL

Precise measurement of theBe7(p,γ)B8
Junghans
¹
,
Mohrmann
²
,
Snover
³

et al. 2003
Phys. Rev. C
140
34
279
4
View full text Add to dashboard Cite

Test of Lorentz invariance inβdecay of polarizedNa20

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Energy levels of light nuclei, A = 20

Cited by 245 publications

References 573 publications

A proposed direct measurement of cross section at Gamow window for key reaction 19F(p,α) 16O in Asymptotic Giant Branch stars with a planned accelerator in CJPL

A proposed direct measurement of cross section at Gamow window for key reaction 19F(p,α) 16O in Asymptotic Giant Branch stars with a planned accelerator in CJPL

Precise measurement of theBe7(p,γ)B8Junghans1, Mohrmann2, Snover3 et al. 2003Phys. Rev. C140342794View full textAdd to dashboardCite

Test of Lorentz invariance inβdecay of polarizedNa20

Contact Info

Product

Resources

About

Precise measurement of theBe7(p,γ)B8
Junghans
¹
,
Mohrmann
²
,
Snover
³

et al. 2003
Phys. Rev. C
140
34
279
4
View full text Add to dashboard Cite