Search results for "POLE"
showing 10 items of 1981 documents
Superdeformation in the Doubly Magic NucleusC2040a20
2001
A rotational band with seven gamma -ray transitions between states with spin 2 (h) over bar and 16 (h) over bar has been observed in the doubly magic, self-conjugate nucleus Ca-40(20)20. The measured transition quadrupole moment of 1.80(-0.29)(+0.39)eb indicates a superdeformed shape with a deformation beta (2) = 0.59(-0.07)(+0.11). The features of this band are explained by cranked relativistic mean field calculations to arise from an 8-particle 8-hole excitation.
Pion generalized dipole polarizabilities by virtual Compton scatteringπe→πeγ
2001
We present a calculation of the cross section and the event generator of the reaction $\ensuremath{\pi}e\ensuremath{\rightarrow}\ensuremath{\pi}e\ensuremath{\gamma}.$ This reaction is sensitive to the pion generalized dipole polarizabilities, namely, the longitudinal electric ${\ensuremath{\alpha}}_{L}{(q}^{2}),$ the transverse electric ${\ensuremath{\alpha}}_{T}{(q}^{2}),$ and the magnetic $\ensuremath{\beta}{(q}^{2})$ which, in the real-photon limit, reduce to the ordinary electric and magnetic polarizabilities $\overline{\ensuremath{\alpha}}$ and $\overline{\ensuremath{\beta}},$ respectively. The calculation of the cross section is done in the framework of chiral perturbation theory at $…
Nuts and dried fruits: Natural occurrence of emerging Fusarium mycotoxins
2013
Abstract The occurrence of enniatins (ENs) and beauvericin (BEA) in nuts, dried fruits and dates available in Valencia (Spain) was surveyed in this study. To do this, seventy-four samples of nuts, dried fruits and dates were analyzed for the determination of mycotoxin contamination. Mycotoxins were identified and quantified using an ultrasonic-C18 extraction and LC–MS/MS with a triple quadrupole (QqQ) mass analyzer. The frequencies of contamination of nuts, shell, dried fruits and dates were 50%, 80%, 35.7% and 83.3%, respectively. Enniatin A (ENA) was the most predominant EN found in nuts (45.2%) while ENB was the most common EN found in dates (58.3%). The analytical results of the shell s…
ATOMISTIC CALCULATIONS OF (110) SURFACE RELAXATION FOR PEROVSKITE TITANATES
1999
Using a shell model, for the first time the (110) surface relaxations are calculated for SrTiO 3 and BaTiO 3 perovskites. The positions of atoms in 16 near-surface layers placed atop a slab of rigid ions are calculated. Strong surface rumpling and surface-induced dipole moments perpendicular to the surface are predicted for both the O-terminated and Ti-terminated surfaces.
The route to high accuracy in ab initio calculations of Cu quadrupole-coupling constants.
2012
We report nonrelativistic and scalar-relativistic coupled-cluster calculations of the copper quadrupole-coupling constants for eleven small copper-containing compounds. It is shown to be necessary to treat both electron-correlation and scalar-relativistic effects on the same footing even for a qualitatively correct description, because both effects are significant and are strongly coupled in the case of Cu electric-field gradients. We show that the three scalar-relativistic schemes employed in the present study--the leading order of direct perturbation theory, the spin-free exact two-component theory in its one-electron variant, and the spin-free Dirac-Coulomb approach--provide accurate tre…
Calculation of atomic spectra and transition amplitudes for superheavy element Db (Z=105)
2018
Atomic spectra and other properties of superheavy element dubnium (Db, $Z=105$) are calculated using recently developed method combining configuration interaction with perturbation theory [the CIPT method, V. A. Dzuba, J. C. Berengut, C. Harabati, and V. V. Flambaum, Phys. Rev. A 95, 012503 (2017)]. These include energy levels for low-lying states of Db and Db II, electric dipole transition amplitudes between the ground state and low-lying states of opposite parity, isotope shift for these transitions, and the ionization potential of Db. Similar calculations for Ta, which is a lighter analog of Db, are performed to control the accuracy of the calculations.
Dipole soliton-vortices
2007
On universal symmetry grounds, we analyze the existence of a new type of discrete-symmetry vortex solitons that can be considered as coherent states of dipole solitons carrying a nonzero topological charge. Remarkably, they can be also interpreted as excited angular Bloch states. The stability of new soliton states is elucidated numerically.
Electromagnetic properties of some positive parity dipole states described in terms of quadrupole and octupole interacting bosons
1990
The first three positive parity dipole states predicted by a phenomenological quadrupole-octupole boson Hamiltonian are extensively studied. Their coupling to the neighboring positive and negative parity states, due to the {ital M}1 and {ital E}{lambda} ({lambda}=1,3) transitions, respectively, are considered. Special attention is paid to the lowest two states which are of collective {ital M}1 nature. The signature which distinguishes them from the {ital M}1 state describing the scissors mode is also discussed.
Lattice QCD and the anomalous magnetic moment of the muon
2019
The anomalous magnetic moment of the muon, a_mu, has been measured with an overall precision of 540 ppb by the E821 experiment at BNL. Since the publication of this result in 2004 there has been a persistent tension of 3.5 standard deviations with the theoretical prediction of a_mu based on the Standard Model. The uncertainty of the latter is dominated by the effects of the strong interaction, notably the hadronic vacuum polarisation (HVP) and the hadronic light-by-light (HLbL) scattering contributions, which are commonly evaluated using a data-driven approach and hadronic models, respectively. Given that the discrepancy between theory and experiment is currently one of the most intriguing …
Evidence for Increased neutron and proton excitations between 51−63 Mn
2015
The hyperfine structures of the odd-even 51−63Mnatoms (N=26 −38) were measured using bunched beam collinear laser spectroscopy at ISOLDE, CERN. The extracted spins and magnetic dipole moments have been compared to large-scale shell-model calculations using different model spaces and effective interactions. In the case of 61,63Mn, the results show the increasing importance of neutron excitations across the N=40subshell closure, and of proton excitations across the Z=28shell gap. These measurements provide the first direct proof that proton and neutron excitations across shell gaps are playing an important role in the ground state wave functions of the neutron-rich Mn isotopes. publisher: Els…