Monopole part of the Majorana force in light nuclei

Neudatchin, V. G.; Smirnov, Yu.F.

doi:10.1016/0029-5582(65)90130-6

Cited by 23 publications

(9 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We expect that doing so with a complex optical potential representation will result in a potential that is less channel dependent until it merges with the diffraction models of high This is a picture that is consistent also with the results obtained using boundary condition models, like the P-matrix formalism [20], and using the Moscow potential approach [28].…”

Section: Optical Model Analysessupporting

confidence: 80%

“…With reasonable values for the meson-nucleon coupling constants and form factor cut-offs, these boson exchange models give quality fits to the data that lead to their nomination as high precision interactions [4,[25][26][27]22]. That is also the case with other approaches such as those with explicitly momentum dependent potential models [24,25], energy independent partial wave potential models [23,25,26], and, with somewhat different approaches, the Moscow potential model [28], and the MIT boundary condition model [9]. These approaches are motivated differently in their formulation but in the end all give essentially the same on-shell NN t-matrices below threshold.…”

Section: Optical Potential -Its Basis and Formmentioning

confidence: 74%

See 1 more Smart Citation

Analysis ofNNamplitudes up to 2.5 GeV: An optical model and geometric interpretation

et al. 1998

View full text Add to dashboard Cite

We analyse the SM97 partial wave amplitudes for nucleon-nucleon (NN) scattering to 2.5 GeV, in which resonance and meson production effects are evident for energies above pion production threshold. Our analyses are based upon boson exchange or quantum inversion potentials with which the subthreshold data are fit perfectly. Above 300 MeV they are extrapolations, to which complex short ranged Gaussian potentials are added in the spirit of the optical models of nuclear physics and of diffraction models of high energy physics. The data to 2.5 GeV are all well fit. The energy dependences of these Gaussians are very smooth save for precise effects caused by the known ∆ and N ⋆ resonances. With this approach, we confirm that the geometrical implications of the profile function found from diffraction scattering are pertinent in the regime 300 MeV to 2.5 GeV and that the overwhelming part of meson production comes from the QCD sector of the nucleons when they have a separation of their centres of 1 to 1.2 fm. This analysis shows that the elastic NN scattering data above 300 MeV can be understood with a local potential operator as well as has the data below 300 MeV.

show abstract

Section: Optical Model Analysessupporting

confidence: 80%

Section: Optical Potential -Its Basis and Formmentioning

confidence: 74%

Analysis ofNNamplitudes up to 2.5 GeV: An optical model and geometric interpretation

et al. 1998

View full text Add to dashboard Cite

show abstract

“…The QF reaction is well described in the the impulse approximation (IA) formalism [34][35][36][37][38][39][40][41][42][43][44][45], provided that (i) the momentum in the initial channel is sufficiently high or the associated wavelength is smaller than the nuclear radius of the Trojan horse nucleus a and the incident nucleus A can interact only with the fragment x, leaving the second fragment s as a spectator; (ii) the incident center-of-mass (c.m.) energy is higher than the binding energy of the clusters x and s in a.…”

Section: A Quasi-free Mechanism and Impulse Approximationmentioning

confidence: 99%

AstrophysicalS(E)factor of theN15(
Cognata
¹
,
Romano
²
,
Spitaleri
³

et al. 2007
Phys. Rev. C

View full text Add to dashboard Cite

The low-energy bare-nucleus cross section for 15 N(p, α) 12 C is extracted by means of the Trojan horse method applied to the 2 H( 15 N,α 12 C)n reaction at E beam = 60 MeV. For the first time we applied the modified half-offenergy-shell resonant R-matrix method that takes into account off-energy-shell effects and initial-and final-state interactions. In particular it has been shown that inclusion of Coulomb 15 N-d scattering and off-shell effects do not affect the determination of the astrophysical factor. Also the simple plane-wave approximation used in previous analyses is justified. The results extracted via the Trojan horse method are compared to direct data in the same energy region and show very good agreement in the energy interval 70-312 keV. These results confirm the extrapolations of the S factor reported in literature.

show abstract

“…Following the simple PWIA, the three body reaction can be factorized into two terms corresponding to the vertices of Fig. 1 and is given by (Neudatchin et al 1965;Jacob et al 1966) …”

Section: The Trojan Horse Methodsmentioning

confidence: 99%

Recent evaluation of the⁷Li(p,α)⁴He reaction rate at astrophysical energies via the Trojan Horse method

Lamia

Spitaleri

Cognata

et al. 2012

A&A

View full text Add to dashboard Cite

Context. The charged-particle induced reactions on lithium have been studied by several works. In particular, several direct measurements of the 7 Li(p, α) 4 He reaction have been performed to extrapolate its low-energy astrophysical S (E)-factor and evaluate the electron screening potential, U e . Aims. In view of recent direct measurements, we discuss our estimate of the bare-nucleus S (E)-factor and an evaluation of the corresponding reaction rate. Moreover, we present the extracted electron screening potential. Methods. The Trojan Horse method (THM) allows us to measure the 7 Li(p, α) 4 He bare-nucleus S (E)-factor down to energies of ∼10 keV, rendering unnecessary the extrapolation procedure typically used by the direct measurements. The 7 Li(p, α) 4 He S (E)-factor is deduced from the 2 H( 7 Li, α 4 He)n reaction by selecting the quasi-free contribution to the reaction yield. The planewave impulse approximation has proved an effective approach as distortions appear negligible. Results. The THM enable us to measure the 7 Li(p, α) 4 He S (E)-factor over the energy region of interest for astrophysics, namely 0.01 < E cm < 0.4 MeV. The zero-energy S (E)-factor and the U e electron screening potential have been measured and compared with the available direct data. From the TH measure of the 7 Li(p, α) 4 He S (E)-factor, the reaction rate calculation has been performed in correspondence with the temperature window of 0.01 < T 9 < 2, which is typical of several astrophysical sites where Li burning could shed light on some open questions, such as mixing phenomena. A variation of ∼13%, with respect the adopted NACRE one, has been found at temperatures of about T 9 = 10 −3 , while a variation of ∼5% has been found at higher temperatures. By considering in the calculation the upper and lower limits to the TH reaction rate, no significant variation in the Li abundances of low mass giant stars follows or, if any modification occurs, this is negligible in comparison to the uncertainties in the free parameters considered in the extra-mixing model of Palmerini and collaborators.

show abstract

Monopole part of the Majorana force in light nuclei

Cited by 23 publications

References 13 publications

Analysis ofNNamplitudes up to 2.5 GeV: An optical model and geometric interpretation

Analysis ofNNamplitudes up to 2.5 GeV: An optical model and geometric interpretation

AstrophysicalS(E)factor of theN15(
Cognata
¹
,
Romano
²
,
Spitaleri
³

et al. 2007
Phys. Rev. C

Recent evaluation of the⁷Li(p,α)⁴He reaction rate at astrophysical energies via the Trojan Horse method

Contact Info

Product

Resources

About

Monopole part of the Majorana force in light nuclei

Cited by 23 publications

References 13 publications

Analysis ofNNamplitudes up to 2.5 GeV: An optical model and geometric interpretation

Analysis ofNNamplitudes up to 2.5 GeV: An optical model and geometric interpretation

AstrophysicalS(E)factor of theN15(Cognata1, Romano2, Spitaleri3 et al. 2007Phys. Rev. C

Recent evaluation of the7Li(p,α)4He reaction rate at astrophysical energies via the Trojan Horse method

Contact Info

Product

Resources

About

AstrophysicalS(E)factor of theN15(
Cognata
¹
,
Romano
²
,
Spitaleri
³

et al. 2007
Phys. Rev. C

Recent evaluation of the⁷Li(p,α)⁴He reaction rate at astrophysical energies via the Trojan Horse method