Search results for "wave function"
showing 10 items of 395 documents
Sensitivity of one-neutron knockout to the nuclear structure of halo nuclei
2019
Background: Information about the structure of halo nuclei are often inferred from one-neutron knockout reactions. Typically the parallel-momentum distribution of the remaining core is measured after a high-energy collision of the exotic projectile with a light target. Purpose:We study how the structure of halo nuclei affects knockout observables considering an eikonal model of reaction. Method: To evaluate the sensitivity of both the diffractive and stripping parallel-momentum distributions to the structure of halo nuclei, we consider several descriptions of the projectile within a halo effective-field theory. We consider the case of Be11, the archetypical one-neutron halo nucleus, impingi…
Two-Quasiparticle Mixing in Odd-Odd Nuclei
2007
In Chap. 16 the residual Hamiltonian was used to mix proton-proton and neutron—neutron two-quasiparticle configurations. The resulting wave functions described states in even-even open-shell nuclei. In this chapter we develop a corresponding formalism, the proton-neutron QTDA, for mixing proton-neutron two-quasiparticle configurations. This mixing produces wave functions that describe states in odd-odd open-shell nuclei. The quasiparticles are obtained from a BCS calculation for an even-even reference nucleus next to the odd-odd nucleus of interest.
Couplings in coupled channels versus wave functions: Application to theX(3872)resonance
2010
We perform an analytical study of the scattering matrix and bound states in problems with many physical coupled channels. We establish the relationship of the couplings of the states to the different channels, obtained from the residues of the scattering matrix at the poles, with the wave functions for the different channels. The couplings basically reflect the value of the wave functions around the origin in coordinate space. In the concrete case of the $X(3872)$ resonance, understood as a bound state of ${D}^{0}{\overline{D}}^{*0}$ and ${D}^{+}{D}^{*\ensuremath{-}}$ (and $c.c.$ From now on, when we refer to ${D}^{0}{\overline{D}}^{*0}$ , ${D}^{+}{D}^{*\ensuremath{-}}$, or $D{\overline{D}}…
Couplings in coupled channels versus wave functions in the case of resonances: Application to the twoΛ(1405)states
2011
In this paper we develop a formalism to evaluate wave functions in momentum and coordinate space for the resonant states dynamically generated in a unitary coupled channel approach. The on-shell approach for the scattering matrix, commonly used, is also obtained in quantum mechanics with a separable potential, which allows one to write wave functions in a trivial way. We develop useful relationships among the couplings of the dynamically generated resonances to the different channels and the wave functions at the origin. The formalism provides an intuitive picture of the resonances in the coupled channel approach, as bound states of one bound channel, which decays into open ones. It also pr…
Theoretical description of the fourth-forbidden non-unique β decays ofCd113andIn115
2006
The half-lives and $\mathrm{log}\mathit{ft}$ values for the fourth-forbidden non-unique beta decays of the ground states of $^{113}\mathrm{Cd}$ and $^{115}\mathrm{In}$ were calculated using a transparent formulation for the ${\ensuremath{\beta}}^{\ensuremath{-}}$ transition amplitude. The microscopic quasiparticle-phonon model (MQPM) was used to calculate the initial and final states of the transitions. The corresponding wave functions were described as linear combinations of one- and three-quasiparticle configurations built in a realistic single-particle model space by using a realistic microscopic two-body interaction. The computed results for the $\mathrm{log}\mathit{ft}$ values and half…
The asymmetry in π−3He scattering
1992
Abstract We show that the π + − 3 He asymmetry data obtained in a recent TRIUMF experiment at T π = 100 MeV can be understood in terms of the elementary π N amplitudes. Through a comparison to a full optical-potential calculation that employs realistic Faddeev wave functions for the trinucleon we show that all nuclear-structure dependence cancels for A y at lower energies. At higher pion energies around the Δ-resonance region the sign flip of A y offers the possibility of extracting information about the smaller partial waves.
Unsubtracted dispersion-relation for longitudinal compton amplitude
1975
Abstract It is shown that there is a simple connection between the slope, at q2 = 0, of the longitudinal Compton amplitude and the electric polarizability of the nucleon. The longitudinal subtraction function is thus known to order q2. The assumption of an unsubtracted dispersion relation for the longitudinal amplitude leads to a sum rule for the electric polarizability. This is a model independent test of the high-energy behaviour of the forward virtual Compton amplitude.
Ground-state spins and moments of72,74,76,78Ga nuclei
2011
Laser spectroscopy was performed on the ${}^{72,74,76,78}$Ga isotopes at On-Line Isotope Mass Separator (ISOLDE) facility, CERN. Ground-state nuclear spins and moments were extracted from the measured hyperfine spectra. The results are compared to shell-model calculations, which provide a detailed probe of the nuclear wave function. The spin is established from the shape of the hyperfine structure and the parity inferred from a comparison of shell-model calculations with the measured nuclear moments. The ground states of ${}^{76,78}$Ga are both assigned a spin and parity of ${I}^{\ensuremath{\pi}}={2}^{\ensuremath{-}}$, while ${}^{74}$Ga is tentatively assigned as ${I}^{\ensuremath{\pi}}={3…
A two-center-oscillator-basis as an alternative set for heavy ion processes
1977
The two-center-oscillator-basis, which is constructed from harmonic oscillator wave functions developing about two different centers, suffers from numerical problems at small center separations due to the overcompleteness of the set. In order to overcome these problems we admix higher oscillator wave functions before the orthogonalization, or antisymmetrization resp. This yields a numerically stable basis set at each center separation. The results obtained for the potential energy surface are comparable with the results of more elaborate models.
Translationally invariant treatment of pair correlations in nuclei - II. Tensor correlations
1998
We study the extension of our translationally invariant treatment of few-body nuclear systems to include tensor forces and correlations. It is shown that a direct application of our method is not as successful for realistic V6 interactions as our previous results for V4 potentials suggested. We investigate the cause in detail for the case of $^4$He, and show that a combination of our method with that of Jastrow-correlated wave functions seems to be a lot more powerful, thereby suggesting that for mildly to strongly repulsive forces such a hybrid procedure may be an appropriate description.