The cross-sections and angular distributions of the D—D reactions between 150 and 450 keV

We present a Monte Carlo method for direct incorporation of nuclear inputs in primordial nucleosynthesis calculations. This method is intended to remedy shortcomings of current error estimation, by eliminating intermediate data evaluations and working directly with experimental data, allowing error estimation based solely on published experimental uncertainties. This technique also allows simple incorporation of new data and reduction of errors with the introduction of more precise data. Application of our method indicates that previous error estimates on the calculated abundances were too large by as much as a factor of three. Since uncertainties in the BBN calculation currently dominate inferences drawn from light-element abundances, the re-estimated errors have important consequences for cosmic baryon density, neutrino physics, and lithium depletion in halo stars. Our direct method allows detailed discussion of the status of the nuclear inputs, by identifying clearly the places where improved cross section measurements would be most useful. 26.35.+c, 98.80.Ft

show abstract

“…Other data for this reaction are from Refs. [40][41][42]. 3 He, so most of the discussion for that reaction carries over to this one.…”

Section: D(d N) 3 Hementioning

confidence: 99%

Estimating reaction rates and uncertainties for primordial nucleosynthesis

2000

View full text Add to dashboard Cite

show abstract

“…units are present below 6 keV. We thus used data sets from Greife et al (1995), Krauss et al (1987), McNeill and Keyser (1951), Schulte et al (1972), Brown and Jarmie (1990), Ganeev et al (1957), Arnold et al (1954), Raiola et al (2002), Booth et al (1956), Leonard et al (2006), Davidenko et al (1957), Hofstee et al (2001), Preston et al (1954), Belov et al (1990), Ying et al (1973), and Bystritsky et al (2010). TH bare nucleus S-factor obtained extracting the quasi-free mechanism from the 2 H( 3 He,n 3 He)H (Tumino et al, 2011(Tumino et al, , 2014 is shown in Figure 2, with a 5% experimental error on the whole data set, from 2.6 keV up to 1.5 MeV, as blue filled triangles and red filled triangles are direct measurements.…”

Section: H(dn) 3 Hementioning

confidence: 99%

Direct and Indirect Measurements for a Better Understanding of the Primordial Nucleosynthesis

Spartà

Pizzone

Bertulani

et al. 2020

Front. Astron. Space Sci.

View full text Add to dashboard Cite

The Big Bang Nucleosynthesis (BBN) model is a great success of nuclear astrophysics due to the outstanding agreement between observational and predicted light elements abundances. One exception, however, is the so-called "lithium problem." In this context, experimental efforts to measure the relevant reactions have been brought to an increased level of accuracy in measuring primordial abundances, and the introduction of indirect methods has allowed researchers to overcome the natural limitations of direct measurements in the energy range of interest for BBN. Here we review the results obtained from the application of the Trojan Horse Method to some of the most influential reactions of the standard network, such as 2 H(d,p) 3 H, 2 H(d,n) 3 He, 3 He(d,p) 4 He, 7 Li(p,α) 4 He, and 7 Be(n,α) 4 He. The relevant cross sections have been then used as new inputs to a classical BBN code, resulting in important constraints that make suggestions for a possible solution for the lithium problem outside of nuclear physics.

show abstract

“…1 displays the data available for the total cross section for the ZH (d, n)-reaction. They are taken from the thin gas target measurements of Arnold et al [23], Booth et al [24], McNeill and Keyser [25] and Preston et al [26]. Therefore, the averaging procedure described in Chap.…”

Section: Ear=at Spa:(e(x))e(x)dx Pat(e(x DX Omentioning

confidence: 99%

“…Is o.1 [26] and Cook and Smith [31]. The data of Wenzel and Whaling [30] were obtained with a thick heavy ice target, for which averaged energies had been assigned by the authors themselve.…”

Section: Cmentioning

confidence: 99%

The (2H-d)-reactions below 200 keV

Fick

Weiss

1973

Z. Physik

View full text Add to dashboard Cite

The 2H(d,n)-and 2H(d,p)-reactions are studied for deuteron energies below 200 keV. It is shown that the R-matrix approach of Konopinski and Teller, which is very sensitive to the channel radius used, can be approximated in a way that the dependence on the channel radius does not appear explicitly. This approach appears to be formally equivalent to a kind of "direct approach" of Boersma. This equivalence answers the question why a direct approach to these reactions works at all at low energies. Each reaction is described by three parameters which are determined in a fit to the up to now available data.

show abstract

The cross-sections and angular distributions of the D—D reactions between 150 and 450 keV

Cited by 34 publications

References 14 publications

Estimating reaction rates and uncertainties for primordial nucleosynthesis

Estimating reaction rates and uncertainties for primordial nucleosynthesis

Direct and Indirect Measurements for a Better Understanding of the Primordial Nucleosynthesis

The (2H-d)-reactions below 200 keV

Contact Info

Product

Resources

About