Determination of the asymptotic normalization coefficients (nuclear vertex constants) for the virtual decayes 3He-> d+p and 17F> 16O+p and their application for extrapolation of the astrophysical s-factors of the proton capture by deutron and 16O nucleus

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DETERMINATION OF THE ASYMPTOTIC NORMALIZATION

COEFFICIENTS (NUCLEAR VERTEX CONSTANTS) FOR THE VIRTUAL DECAYES

3He→ d+p AND 17F→ 16O+p

AND THEIR APPLICATION FOR EXTRAPOLATION OF THE ASTROPHYSICAL S-FACTORS OF THE PROTON

CAPTURE BY DEUTRON AND 16O NUCLEUS AT SOLAR ENERGIES

S.V. Artemov, S.B. Igamov, K. Tursunmakhatov, and R.Yarmukhamedov

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CONTANTS 1. Introduction

2. Modified two-body potential approach for the direct radiative capture A(a,)B reaction 3. Analysis of the direct radiative capture

D( p, )3He and 16O(p, )17Freactions

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1. Introduction

A reliable estimation of rates of different nuclear astrophysical processes responsible for the light elements abundance ( for example, 6,7Li,

Be, B, C, N, O etc.) is one of the most

important problem of the modern nuclear astrophysics

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pp-chain

p+p  d+e+ + ν e D+p  3He+ 3He+ 3He 4He+ p+p 3He 4He 7Be+  7Be+ p 8B + (8B  8Be + e+ + ν e ) (4p  4He ) (Q =26.7 MeV, T  107 K, E_ν= 0.5  6 MeV)

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“

hot” pp-chain (CNO - cycle)

12C+ p13N+ 3N13C+e++ν e 13C +p14N+  14N+ p15O+  15O15N+ e+ +ν e 15N+ p16O+



16O+ p17F+ 

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A critical analysis of low-energy astrophysical S-factors

data made in work of the authors of E.G. Adelberger et al. [Rev.Mod.Phys. 70(1998)1265)] found out the following facts:

• The extrapolation of measured astrophysical S-factors

to lower energies is noticeable ambiguous due to a presence of rather large spread in them.

• The theoretical predictions for S(E) at astrophysically

relevant energies (~ 25 keV) are not always accurate since its depends on input parameters ( for example on a form of the nuclear potential)

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2. Modified two-body potential

approach for the direct

radiative capture

A(a,)B

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3. Analysis of the direct radiative capture D( p, )3He and 16O(p, )17F reactions

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ANC for 3Hed+p

C2 =4.280.50fm-1 |G|2 =1.340.15 fm

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Exp. data – G.J. Schmid et al. Phys.Rev.C56(1997) Exp.data – C.Casella et al. Nucl.Phys. A706(1997) S_pd(0)=0.1620.019 eVb

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our result C2 =1.090.11_fm-1 our result C2 =5700225 fm-1 ANC for 17F(gs)16O+p 17F(0.495MeV)16O+p Gagliardi C.A. et al Phys.Rev.C59(1999) C2 =1.090.11 fm-1 Gagliardi C.A. et al Phys.Rev.C59(1999)

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The astrophysical S factor for our result S(0)=9.450.40 keVb Gagliardi C.A. et al Phys.Rev.C59(1999) S(0)=9.450.40 keVb

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CONCLUSION

Thus,the modified two- body potential approach for the direct radiative capture reaction

(IYa. Nucl.Phys(2007) )

allows to determine the ANC’s

for 3Hed+p and 17F16O+p,

which can then be used for the reliable extrapolation of the astrophysical factors for the d(p,)3He and 16O(p, ) 17F reactions

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