Inelastic collisions and threshold effects

Fonda, L.

doi:10.1007/bf02822640

Cited by 21 publications

(6 citation statements)

References 24 publications

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“…117 and the C 2 coefficient is given by equation (11). We continue the discussion on the basis of u,,~.,, for a given N. This holds directly for N = 0, i.e.…”

Section: The Bound State Wavefunctions and Angular Momentum Couplingmentioning

confidence: 98%

“…(16) For our problem we have made the replacements uz-+~{' and Gt+-+Gf+; these are the corresponding Coulomb functions described in the Appendix. Here U~,,~,Me excludes the/L = 0 term (see equation (21)) and thus is the potential in addition to the Coulomb one [11], [7 (a)]. The q~f are real hence we omit the * hereafter, and for (G~+) * we write G ~-.…”

Section: Integral Equations and Asymptotic Expressionsmentioning

confidence: 98%

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On the coupling in the final state in the photoelectron spectra

Kálmán

1982

Molecular Physics

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The coupling in the state e+ ~/B + for the He I photoelectron spectra is considered by explicit calculation of the appropriate $+ matrix elements. Coulomb functions are taken for the asymptotic states and the additional interaction is approximated by an electrostatic multipole expansion. A fixed body frame treatment is used. The coupling St elements are given, to first and second order, by multipole integrals and differ according to the change in electronic state energy and R dependence involved. In the approximation used the symmetry (i.e. A) of the electronic states remains the same. Vibrational effects are found to depend on whether the identical or different electronic potential curves occur in the multipole matrix elements. Harmonic oscillator selection rules or the displaced oscillator integrals, respectively, determine the extent of the coupling in these two cases. A sample computation is presented for the N~+(X ~Xg) state.

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“…117 and the C 2 coefficient is given by equation (11). We continue the discussion on the basis of u,,~.,, for a given N. This holds directly for N = 0, i.e.…”

Section: The Bound State Wavefunctions and Angular Momentum Couplingmentioning

confidence: 98%

Section: Integral Equations and Asymptotic Expressionsmentioning

confidence: 98%

On the coupling in the final state in the photoelectron spectra

Kálmán

1982

Molecular Physics

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“…Set 1 is the set originally favored and was the set adopted by Adair The downward cusp is in agreement with the study by Fonda. 17 However, Alfimenkov et al 27 have now shown conclusively, by their measurements of the transmission of polarized neutrons through a polarized deuterium target, that it is set 2 which is correct, so that the quartet scattering length is large and the doublet scattering length is small. This conclusion agrees with the calculations of Aaron et al and of Phillips which we have discussed in Sees.…”

Section: The Existence Of the Dineutronmentioning

confidence: 99%

“…It has been suggested 16,17 that threshold effects such as a cusp or rounded step might appear in the n-d elastic-scattering and total cross section at theH 2 (^,^2)H 1 threshold if the dineutron (n 2 ) exists in a bound state. Since the exclusion principle prevents two neutrons from occupying a 8 Si state, the forces acting in the S state of the dineutron cannot be compared with the n-d TOTAL CROSS SECTION 765 forces binding the 3 5i state of the deuteron, but must be compared with those acting in the ^o state of the n-p system.…”

Section: The Dineutronmentioning

confidence: 99%

n−dTotal Cross Section, Three-Nucleon Problem, and the Dineutron

Glasgow

Foster

1967

Phys. Rev.

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The n-d total cross section was measured at 241 different energies to a precision of 5.7-1.0% and an energy resolution of 2.0-5.1% for 2.25 <£"< 15.0 MeV. The results support the correctness of present three-body calculations, and exhibit no evidence for a Wigner cusp near the predicted threshold for dineutron production. In the absence of such a cusp, an experiment of this type furnishes very little information regarding the existence of the dineutron, or of violations of charge independence. 157

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“…The conditions which must be satisfied are: (1) there are only two outgoing particles in the threshold channel, 43,44 (2) the outgoing particles have no Coulomb interaction between them, 42 and (3) the outgoing particles have zero relative orbital angular momentum. 42 Furthermore, a study of the cross section in the vicinity of the anomaly can give information about spins and relative parities.…”

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confidence: 99%

Neutron-Alpha Scattering in the 20-MeV Range

Shamu

Jenkin

1964

Phys. Rev.

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Angular distributions of neutrons scattered by a particles were measured from 16-to 26-MeV neutron energy by observing the recoiling a particles in a high-pressure gas scintillator. Above 22 MeV, disintegration particles from the He i (n,d)T reaction were observed, also. Data were taken in 25-keV steps over the He 5 state at 16.7-MeV excitation energy (22.15-MeV neutron energy) and over the He 4 (w,w/>)T, He 4 (^,w')He 4 *, and He 4 (w,2w)He 3 thresholds. Total cross sections of helium were measured at 26 energies from 20-to 29-MeV neutron energy in a good geometry transmission experiment. Angular distributions at neutron energies < 24 MeV were fitted with expansions of Legendre polynomials. Polynomials of order 0 through 4 provided a satisfactory fit. Below 22 MeV the angular distributions agree with calculations based on n-a phase shifts suggested by Perkins. Above 22 MeV the agreement is not as good. The total cross sections agree only qualitatively with these calculations. The total cross section and angular-distribution data are consistent with a § + assignment for the 16.7-MeV level. The measured yield curve for the He 4 (n,d)T reaction agrees with that computed from the cross section for the inverse reaction. * Present address: Atomic Energy Research Establishment, Harwell, England. 1 1. S. Trostin, V. A. Smotryaev, and I. I. Levintov, Zh.

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Inelastic collisions and threshold effects

Cited by 21 publications

References 24 publications

On the coupling in the final state in the photoelectron spectra

On the coupling in the final state in the photoelectron spectra

n−dTotal Cross Section, Three-Nucleon Problem, and the Dineutron

Neutron-Alpha Scattering in the 20-MeV Range

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