The Reid93 potential provides a representation of the nucleon–nucleon (
NN
) scattering data that rivals that of a partial wave analysis. We present here a unitary pole approximation (UPA) for this ...contemporary
NN
potential that provides a rank one separable potential for which the wave function of the deuteron (
3
S
1
-
3
D
1
) and singlet anti-bound (
1
S
0
) state are exactly those of the original potential. Our motivation is to use this UPA potential to investigate the sensitivity of the electric dipole moment for the deuteron and
3
H and
3
He to the ground state nuclear wave function. We compare the Reid93 results with those for the original Reid (Reid68) potential to illustrate the accuracy of the bound state properties.
Conjecture: A Possible nn Λ Resonance Gibson, B. F.; Afnan, I. R.
EPJ Web of Conferences,
01/2016, Letnik:
113
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
We address the question of whether there might exist a resonance in the nnΛ system, using a rank one separable potential formulation of the Hamiltonian. We explore the eigenvalues of the kernel of ...the Faddeev equation in the complex energy plane using contour rotation to allow us to analytically continue the kernel onto the second energy sheet. We follow the largest eigenvalue as the nΛ potentials are scaled and the nnΛ continuum is turned into a resonance and then into a bound state of the system.
The unitary pole approximation (UPA) provides an effective means to construct a rank one separable potential for calculations in which one requires a simple representation of the deuteron and/or ...triton ground-state wave function. By construction the deuteron wave function and the
1
S
0
anti-bound state wave function of the original potential are reproduced. We report results for the corresponding triton ground state. We choose to utilize the realistic Reid93 potential for this purpose. The Reid93 potential, generated by the Nijmegen group, is a Reid-like, partial-wave local potential that produces a χ
2
representation of the nucleon–nucleon (
NN
) scattering data that is as precise as an
NN
partial-wave analysis. Results for properties of
2
H and
3
H from the UPA are compared with those for the original potential. To further illustrate the precision of the method, results for properties of the deuteron and triton from the UPA are also compared with those for the original Reid68 potential.
A definitive measurement of an electric dipole moment (EDM) would likely imply new physics beyond the standard model. Although the standard model strong interaction term could theoretically produce ...an EDM of any size, that it is constrained by the current neutron EDM limit to be some 10 orders of magnitude smaller than 1 suggests that the electroweak sector and CP violation will be the source of a measurable EDM. The weak interaction standard model EDM is itself orders of magnitude smaller than contemporary experiments can measure. Direct measurement of the neutron EDM lies in the next decade; measurement of the proton EDM could well come first. A BNL proposal for an electrostatic storage ring measurement lies in the offing. Unless the EDM proves to be an isoscalar, one will need other measurements to separate the isoscalar, isovector, and isotensor components. Measurement of a nuclear EDM will be required:
2
H,
3
H, or
3
He being the simplest nuclear systems. A storage ring measurement of the triton EDM could be accomplished in a manner analogous to that proposed for the proton. However, the deuteron EDM measurement offers certain advantages, even though the experiment would be more complex, involving electric and magnetic fields, than that required for the proton and triton. The COSY facility in the Forschungszentrum Juelich is almost an ideal facility to house such an experiment; one could also measure in the same ring the EDM for the proton and He. The deuteron is the one nucleus for which exact model calculations can easily be performed. We briefly explore the model dependence of deuteron EDM calculations. Using a separable potential formulation of the Hamiltonian, we examine the sensitivity of the deuteron EDM to variations in the nucleon–nucleon interaction, including contemporary potential models, and we explore the dependence upon intermediate state multiple scattering in the
3
P
1
channel. We investigate the tensor force contribution to the model results and examine the effects of short-range repulsion that characterize realistic, contemporary potential models of the deuteron. Because one-pion exchange dominates the EDM calculation, separable potential model calculations appear to provide an adequate description of the deuteron EDM until such time as a measurement of better than 10 % is achieved.
Here, a mass spectroscopy experiment with a pair of nearly identical high resolution spectrometers and a tritium target was performed in Hall A at Jefferson Lab. Utilizing the (e,e'K+) reaction, ...enhancements, which may correspond to a possible $\Lambda$nn resonance and a pair of ΣNN states, were observed with an energy resolution of about 1.21 MeV (σ), although greater statistics are needed to make definitive identifications. An experimentally measured Λnn state may provide a unique constraint in determining the Λn interaction, for which no scattering data exist. In addition, although bound A = 3 and 4 Σ hypernuclei have been predicted, only an A = 4 Σ hypernucleus ($^4_Σ$He) was found, utilizing the (K-,π-) reaction on a 4He target. The possible bound ΣNN state is likely a Σ0nn state, although this has to be confirmed by future experiments.
Here, a mass spectroscopy experiment with a pair of nearly identical high resolution spectrometers and a tritium target was performed in Hall A at Jefferson Lab. Utilizing the (e,e'K+) reaction, ...enhancements, which may correspond to a possible $\Lambda$nn resonance and a pair of ΣNN states, were observed with an energy resolution of about 1.21 MeV (σ), although greater statistics are needed to make definitive identifications. An experimentally measured Λnn state may provide a unique constraint in determining the Λn interaction, for which no scattering data exist. In addition, although bound A = 3 and 4 Σ hypernuclei have been predicted, only an A = 4 Σ hypernucleus ($^4_Σ$He) was found, utilizing the (K-,π-) reaction on a 4He target. The possible bound ΣNN state is likely a Σ0nn state, although this has to be confirmed by future experiments.
We investigate deep inelastic scattering from
3He and
3H within a conventional convolution treatment of binding and Fermi motion effects. Using realistic Faddeev wave functions together with a ...nucleon spectral function, we demonstrate that the free neutron structure function can be extracted in deep-inelastic scattering from
A=3 mirror nuclei, with nuclear effects canceling to within 2% for
x≲0.85.
Thermo-electric generators (TEGs) have been identified as promising solid-state devices to recover exhaust waste in internal combustion engines (ICEs). As the TEGs are able to convert heat directly ...into electricity, they can be used to down size the alternator of the ICEs. However, the addition of new devices to the engine exhaust system leads to increase the back pressure of the engine and reduces the overall efficiency of the engine. Therefore, this study is conducted to understand the possibility of integrating the TEG to the muffler of the engine, without interrupting the functionality of the muffler to recover the waste heat of the engine exhaust system. Findings of the study shows that the thermo-electric modules (TEMs) can be easily integrated to the muffler and electricity can be conveniently generated using the exhaust energy available in the hot exhaust gas.
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