119412029
T=0 neutron-proton pairing correlations in the superdeformed rotational bands around Zn-60
The superdeformed bands in Cu-58, Cu-59, Zn-60, and Zn-61 are analyzed within the frameworks of the Skyrme-Hartree-Fock as well as Strutinsky-Woods-Saxon total Routhian surface methods with and wit ...
16534405
Solution of the Skyrme—Hartree—Fock equations in the Cartesian deformed harmonic oscillator basis II. The program HFODD
Abstract We describe a method of solving the nuclear Skyrme-Hartree-Fock problem by using a deformed Cartesian harmonic oscillator basis. The complete list of expressions required to calculate local densities, total energy, and self-consistent fields is presented, and an implementation of the self-consistent symmetries is discussed. Formulas to calculate matrix elements in the Cartesian harmonic oscillator basis are derived for the nuclear and Coulomb interactions.
24677742
Critical frequency in nuclear chiral rotation.
Self-consistent solutions for the so-called planar and chiral rotational bands in 132La are obtained for the first time within the Skyrme-Hartree-Fock cranking approach. It is suggested that the chiral rotation cannot exist below a certain critical frequency which under the approximations used is estimated as Planck's omega(crit) approximately 0.5-0.6 MeV. However, the exact values of Planck's omega(crit) may vary, to an extent, depending on the microscopic model used, in particular, through the pairing correlations and/or calculated equilibrium deformations. The existence of the critical frequency is explained in terms of a simple classical model of two gyroscopes coupled to a triaxial rigid body.
23672287
Superdeformation in the quasicontinuum: Microscopic view of the excited superdeformed bands and the corresponding level densities.
Microscopic calculations of both the normal and the superdeformed rotational bands have been performed for a number of rare earth nuclei. The universal'' Woods-Saxon potential and the extended Strutinsky method have been used. Excited bands up to a prescribed energy limit {ital E}{sup *} (usually 2.5 to 3.5 MeV) have been calculated individually by minimizing the corresponding nuclear energies over the quadrupole and hexadecapole deformations. This turns out to be essential, when comparing with experimental results for the known discrete bands. An important influence of the superdeformed neutron ({ital N}=86) shell closure on the microscopically calculated rotational-level densities is illustrated and discussed.
119356133
The Shears Mechanism in 142Gd in the Skyrme-Hartree-Fock Method with the Tilted-Axis Cranking
We report on the first Skyrme-Hartree-Fock calculations with the tilted-axis cranking in the context of magnetic rotation. The mean field symmetries, differences between phenomenological and self-consistent methods and the generation of shears-like structures in the mean field are discussed. Significant role of the time-odd spin-spin effective interaction is pointed out. We reproduce the shears mechanism, but quantitative agreement with experiment is rather poor. It may have to do with too large core polarization, lack of pairing correlations or properties of the Skyrme force.
119453196
Search for the Jacobi shape transition in light nuclei
Abstract.The $\gamma$-rays following the reaction 105 MeV 18O + 28Si have been measured using the EUROBALL IV, HECTOR and EUCLIDES arrays in order to investigate the predicted Jacobi shape transition. The high-energy $\gamma$-ray spectrum from the GDR decay indicates the presence of large deformations in the hot 46Ti nucleus, in agreement with new theoretical calculations based on the rotating liquid-drop model.
123280722
CHARMONIUM EXCITED STATES FROM LATTICE QCD
We apply the variational method with a large basis of interpolating operators to demonstrate the feasibility of extracting multiple excited states in charmonium from lattice QCD. The calculation is performed in the quenched approximation to QCD, using the clover fermion action on an anisotropic lattice. A crucial element of our approach is a knowledge of the continuum limit of the interpolating operators, providing important additional information on the spin assignment of the states, even at a single value of the lattice spacing. Though we find excited-state masses that are systematically high with respect to the quark potential model, and the experimental masses where known, we attribute this as most likely an artifact of the quenched approximation.
123115763
Excited charmonium physics from lattice QCD
Properties of excited mesons are studied using a lattice QCD simulation of a system comparable to charmonium. We extract a spectrum of states, including those with manifestly exotic quantum numbers. Radiative transition form‐factors are also computed, in particular the transition from exotic ηc1 to J/ψγ which is found to be large on the usual scale of magnetic dipole transitions.Properties of excited mesons are studied using a lattice QCD simulation of a system comparable to charmonium. We extract a spectrum of states, including those with manifestly exotic quantum numbers. Radiative transition form‐factors are also computed, in particular the transition from exotic ηc1 to J/ψγ which is found to be large on the usual scale of magnetic dipole transitions.
120601853
Radiative Physics in Charmonium from Lattice QCD
Charmonium is an attractive system for the application of lattice QCD methods owing to the possibility of computing with the physical quark mass in a reasonable time. While the sub-threshold spectrum has been considered in some detail in previous works, it is only very recently that further properties such as radiative transitions and two-photon decays have come to be calculated; herein we discuss this recent progress.
118476812
Energy dependence of the $\rho$ resonance in $\pi\pi$ elastic scattering from lattice QCD
We determine the energy-dependent amplitude for elastic {pi} {pi} P-wave scattering in isospin-1 by computing part of the discrete energy spectrum of QCD in finite cubic boxes. We observe a rapidly rising phase shift that can be well described by a single {rho} Resonance. The spectrum is obtained from hadron correlators computed using lattice QCD with light quark masses corresponding to m{sub {pi}}~400 MeV. Variational analyses are performed with large bases of hadron interpolating fields including, as well as fermion bilinears that resemble q{anti q} Constructions, also operators that look like pairs of pions with definite relative and total momentum. We compute the spectrum for a range of center-of-mass momenta and in various irreducible representations of the relevant symmetry group. Hence we determine more than thirty values of the isospin-1 P-wave scattering phase shift in the elastic region, mapping out its energy dependence in unprecedented detail.
119183361
Charmonium in lattice QCD and the nonrelativistic quark model
We compare the results of a numerical lattice QCD calculation of the charmonium spectrum with the structure of a general nonrelativistic potential model. To achieve this we form the nonrelativistic reduction of derivative-based fermion bilinear interpolating fields used in lattice QCD calculations and compute their overlap with cc meson states at rest constructed in the nonrelativistic quark model, providing a bound-state model interpretation for the lattice data. Essential gluonic components in the bound states, usually called hybrids, are identified by considering interpolating fields that involve the gluonic field-strength tensor and which have zero overlap onto simple cc model states.