Search results for "Wave function"
showing 10 items of 395 documents
Heavy-mesons exchange and the backward deuteron electrodisintegration
1992
Backward electrodisintegration of the deuteron is calculated using an exchange-current operator containing π, η, ρ, ω, δ, σ, andA1 exchanges. The deuteron and1S0np wave functions are derived from the Bonn OBEPs. For completeness, we introduced theA1-meson exchange into the OBEP's as well. As a consequence, the value ofD-state probabilityPD is increased by 0.2%–0.8%. The computed cross sections are compared with new data.
Contributions to the electromagnetic form factors of the deuteron from isobar configurations
1974
A nonrelativistic calculation of the elastic electron deuteron scattering has been performed in which the effects arising from nucleon polarization have been systematically investigated. These effects have been taken into account by admixing isobar configurations into the deuteron wave function. Explicit expressions for the various contributions to the respective deuteron form factors have been given. At higher momentum transfers inclusion of the isobar configurations leads to a substantial increase in the form factors which qualitatively appears to account for at least some of the discrepancies between theory and experiment.
Probing the nuclide 180W for neutrinoless double-electron capture exploration
2011
Abstract The mass difference of the nuclides 180 W and 180 Hf has been measured with the Penning-trap mass spectrometer SHIPTRAP to investigate 180 W as a possible candidate for the search for neutrinoless double-electron capture. The Q ϵ ϵ -value was measured to 143.20(27) keV. This value in combination with the calculations of the atomic electron wave functions and other parameters results in a half-life of the 0 + → 0 + ground-state to ground-state double-electron capture transition of approximately 5 × 10 27 years / 〈 m ϵ ϵ [ eV ] 〉 2 .
Coherent ψ(2S) photo-production in ultra-peripheral Pb Pb collisions at sNN=2.76 TeV
2015
We have performed the first measurement of the coherent ψ(2S) photo-production cross section in ultraperipheral Pb–Pb collisions at the LHC. This charmonium excited state is reconstructed via the ψ(2S) → l +l − and ψ(2S) → J/ψπ+π− decays, where the J/ψ decays into two leptons. The analysis is based on an event sample corresponding to an integrated luminosity of about 22 μb−1. The cross section for coherent ψ(2S) production in the rapidity interval −0.9 < y < 0.9 is dσcoh ψ(2S)/dy = 0.83±0.19 stat+syst mb. The ψ(2S) to J/ψ coherent cross section ratio is 0.34+0.08 −0.07(stat + syst). The obtained results are compared to predictions from theoretical models.
Review of the properties of the 0νβ−β−nuclear matrix elements
2012
In this work we investigate general properties of the nuclear matrix elements (NMEs) related to the neutrinoless double ?? decays (0????? decays) of several nuclei of interest for double-beta-decay experiments. A summary of the values of the NMEs calculated along the years by the Jyv?skyl??La Plata collaboration is given. These NMEs are compared with those of the other available calculations and general conclusions are drawn based on these comparisons.
Hybridization ofsd- andfp-shell proton orbitals in the systemS36+37Cl
1993
Experimental and theoretical evidence is presented that the proton exchange is strongly enhanced by a mixing of single-particle configurations in $^{37}\mathrm{Cl}$ (in the system $^{36}\mathrm{S}$${+}^{37}$Cl, which is shown to be the clearest example of hybridization in nuclear physics. The experimental data on elastic and inelastic transfer are only reproduced if the complete set of single-particle states (${\mathit{d}}_{3/2}$,${\mathit{s}}_{1/2}$,${\mathit{f}}_{7/2}$,${\mathit{p}}_{3/2}$,${\mathit{f}}_{5/2}$, and ${\mathit{p}}_{1/2}$) is included in a coupled-reaction-channel calculation. The strong enhancement is explained by the hybridization of orbits of different parity. In a two-ce…
Adiabatic Time-Dependent Hartree-Fock Calculations of the Optimal Path, the Potential, and the Mass Parameter for Large-Amplitude Collective Motion
1980
The adiabatic time-dependent Hartree-Fock theory is reformulated in order to yield a simple differential equation for the collective path with accompanying simple expressions for the collective mass and the potential. With use of three-dimensional coordinate- and momentum-space techniques and density-dependent interactions, the new adiabatic time-dependent Hartree-Fock formalism is applied to $\ensuremath{\alpha}\ensuremath{-}\ensuremath{\alpha}$ scattering and correspondingly to the fission mode of $^{8}\mathrm{Be}$. In the overlapping region the resulting collective mass deviates strongly from the reduced mass.
Pion interaction with the trinucleon up to the eta production threshold
1993
Pion elastic, charge exchange scattering and induced eta production on the trinucleon systems are investigated in a coupled-channels approach in momentum space with Fadeev wave functions. The channel $\pi N \rightarrow \eta N$ is included using an isobar model with S-, P-, and D-wave resonances. While the coherent reactions like $^3$He($\pi,\pi)^3$He can be reasonably well reproduced up to $T_{\pi}$=500 MeV, large discrepancies appear for the incoherent processes, $^3$He($\pi^-,\pi^0)^3$H and $^3$He($\pi^-,\eta)^3$H at backward angles and energies above $\Delta$-resonance. In the forward direction the $(\pi,\eta)$ calculations underestimate the experimental measurements very close to thresh…
g factors of $^{31,32,33}$Al: Indication for intruder configurations in the $^{33}$Al ground state
2006
Abstract The g factors of 31,32,33 Al have been measured using the β -nuclear magnetic resonance ( β -NMR) technique on spin-polarized beams produced in the fragmentation of a 36 S (77.5 MeV/u) beam on a 9 Be target. Nearly pure beams of Al ( Z = 13 ) isotopes were selected with the high-resolution fragment separator LISE at GANIL. An asymmetry as high as 6% has been observed in the β -NMR curve for 32 Al implanted in a Si single crystal. The magnetic moment of the N = 20 nucleus 33 Al is obtained for the first time: μ ( Al 33 , I π = 5 / 2 + ) = 4.088 ( 5 ) μ N , while those of 31,32 Al are obtained with improved accuracy: μ ( Al 31 , I π = 5 / 2 + ) = 3.830 ( 5 ) μ N and μ ( Al 32 , I π =…
Can relativistic pionic stripping explain (p,π+) reactions?
1978
The relativistic pionic stripping formalism is used to study pion production data on $^{12}\mathrm{C}$ and $^{40}\mathrm{Ca}$ in order to determine the appropriate form of the pion-nucleon vertex and to determine whether pionic stripping is the dominant mechanism for pion production.