Search for the Trineutron

Thornton, S.T.; Bair, J.K.; Jones, C.M.; Willard, H. B.

doi:10.1103/physrevlett.17.701

Cited by 46 publications

(14 citation statements)

References 7 publications

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“…The Hamada-Johnston predictions (dashed curve) tend to be above our results. Recent estimates by Marker and Signell 14 show that Coulomb effects reduce the Hamada-Johnston predictions by about 5% at 62 MeV and 6% at 47 MeV. Although one cannot at this time make any firm statements about the best choice of nucleon-nucleon potential, it does appear from the present results that a momentum-dependent potential is preferable to a hard-core potential.…”

contrasting

confidence: 43%

Search for States in the Three-Neutron and Triton Systems

1968

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The original estimate 5 was set at the 90% confidence level. To conform with the prevailing custom of quoting a standard deviation, we have reduced our original estimate of error by a factor of 1.65. Figure 4 shows the coplanar cross sections (integrated over 7-ray angle) for (30°, 30°) as a function of bombarding energy. The curves are theoretical predictions, identified in the caption, while the plotted points show the corrected experimental results listed in Table III. It is evident from Fig. 4 that our five measurements (solid points) are lower than the others at similar energies. It is possible that the type of prompt background eliminated in our work by the baffles B have could caused an excess of counts in the other work.Our results at 47 MeV fall significantly below the calculation by Nyman 12 of the model-independent leading terms of the integrated cross section. The reason for this is not understood at present.Of the calculations based on various potential models of the nucleon-nucleon interaction, our data agree best with the calculation of Ref. 9 based on the Tabakin potential (dash-dot curve), although more refined calculations with this potential give larger cross sections. 13 Our points are generally consistent with a prediction based on the Bryan-Scott potential (solid curve). The Hamada-Johnston predictions (dashed curve) tend to be above our results. Recent estimates by Marker and Signell 14 show that Coulomb effects reduce the Hamada-Johnston predictions by about 5% at 62 MeV and 6% at 47 MeV. Although one cannot at this time make any firm statements about the best choice of nucleon-nucleon potential, it does appear from the present results that a momentum-dependent potential is preferable to a hard-core potential.3 He spectra from the bombardment of tritium and of 3 He targets with 22.25-MeV tritons are presented. No clear evidence for new states in either residual nucleus is obtained; however, the 3 H(2, 3 He)3w spectra provide weak evidence for the existence of a "trineutron" unbound by 1 to 1.5 MeV.

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contrasting

confidence: 43%

Search for States in the Three-Neutron and Triton Systems

1968

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“…However, the discovery of several incontrovertible examples of "steric" isotope effects (for references, see [6]) albeit in highly hindered systems, makes it necessary to consider a possible steric origin of the isotope effects even in the present unlikely case. This is particularly advisable in view of Brown's recent adoption of the extreme view that all secondary isotope effects are steric [7].…”

Section: Discussionmentioning

confidence: 99%

“…Vol. 6,1968 COMPLEX BETWEEN AROMATIC HYDROCARBONS AND HCL (b) Differential measurement of toluene vs benzene. Two such measurements yielded: &Ar = 0.726 ± .024 X 10-3 Torr-I, which can be compared with the difference between the averages of the directly measured values:…”

Section: (A) Absolute Measurementsmentioning

confidence: 99%

Secondary Isotope Effects Part IV Complex Formation Between Aromatic Hydrocarbons and HCl,

Halevi

Ravid

1968

Israel Journal of Chemistry

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The isotope effects on complex formation between HCl and variously deuterated benzenes and toluenes have been measured at −80°C, using a differential solubility technique. Both methyl and nuclear deuteration increase the basicity of the hydrocarbon, the two effects being additive in toluene. All the results can be fit with values of: δ FM° = −3.15− cal / g. atom D for methyl deuteration of toluene, and δ FN° = −3.56− cal/g. atom D for nuclear deuteration of either benzene or toluene. The implications of these results for the theory of secondary isotope effects are discussed.

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“…Previous work has set limits on the production of' a triproton [2] or ' trineutron [4] system and provides rough values of' the cross section f'or the formation of' the f'our-body f'inal state. In the present experiment we have measured the neutron spectrum f'rom the 3 He(p,n)3p reaction at a proton energy of' 24.9 MeV.…”

Section: Ucrl-18929mentioning

confidence: 99%