Charge form factor of Li6

The charge form factor of Li⁶ are calculated using an exponential type of wave function to describe its ground state. The value of the parameter in the wave function is obtained by fitting the root-mean-square radius for the above wave function to the experimental value. We found our calculated charge form factor in excellent agreement with those obtained from electron-Lithium scattering experiments. This shows that our wave function for Li⁶ is quite satisfactory.     

Universal formula for calculation of the ion form factor

The analytical expression of the atomic form factor has been obtained for the atoms of arbitrary nuclear charge Z and high degree of ionization.     

Self-consistent center-of-mass correction and the charge form factor of He

The Hartree-Fock approximation is used for ⁴He in the case of Lipkin's Hamiltonian with several nuclear forces. The self-consistent solution practically coincides with the one obtained in the usual HF method applied to the intrinsic Hamiltonian; however, the center of mass is now in its ground state, and its motion is fairly separated in the ground state function of the nucleus. An unambiguous comparison between experimental and theoretical charge form factor is done. The discrepancies cannot be interpreted as due to spurious c.m. effects.     

τ-d overlap function and the τ charge form factor

An Eckart-form parameterization of the τ-d overlap function is shown to give excellent fits to the τ charge form factor and radius. The function is constrained to have the correct asymptotic behavior and succesfully reproduces the diffraction dip at 11.6 fm^?2.     

Charge form factor and cluster structure of the 6Li nucleus

The charge form factor of the 6Li nucleus is considered on the basis of its cluster structure. The charge density of ⁶Li is presented as a superposition of two terms. One of them is a folded density and the second one is a sum of the ⁴He and deuteron densities. Using the available experimental data for ⁴He and deuteron charge form factors, a satisfactory agreement of the calculations within the suggested scheme is obtained with the experimental data for the charge form factor of ⁶Li, including those in the region of large transferred momenta.      

Center of mass spuriosity effects on the charge form factor in many-body theories

The effect of c.m. spuriosity on the charge form factor of the nuclei ⁴He and ¹⁶O is studied by assuming 0747 Saxon-Wood wave functions as selfconsistent wave functions. It is found that this effect is quite large at high momentum transfer.     

RPA calculation of the effective charge in a hartree-fock basis

Using a Hartree-Fock basis the diagrams of the Tamm-Dancoff and random-phase approximations have been summed to calculate the effective charge in the (1s0d) shell. The enhancement of the effective charge found by this summation is much less than in an oscillator basis, in fact in most cases the HF RPA result is smaller than the value obtained from the lowest order core polarization diagram in an oscillator basis. The HF neutron effective charges are thus too small. For protons the enhancement of the bare effective charge in a HF basis must also be taken into account, but for cases involving the 0d_5/2 orbital the final result appears rather small.     

Analysis of excited quark propagator effects on neutron charge form factor

The European Physical Journal A - The first neutron star (NS) merger observed by advanced LIGO and Virgo, GW170817, and its fireworks of electromagnetic counterparts across the entire...     

Some remarks on the charge form factor of He and the center-of-mass motion spuriousity

It is shown that the various single-particle wave functions used to reproduce the charge form factor of ⁴He nucleus contain a large amount of center-of-mass motion spuriousity, so that the good fit to the experimental data obtained with these wave functions is only due to the way the center-of-mass motion coordinate was removed rather than to the characteristics of the model.     

The effect of the Δ(1236) on the trinucleon charge form factor

The Δ(1236) is introduced into the wavefunctions of³He and³H and the charge form factor calculated. The effect is to slightly aggravate the already large discrepancy between theory and experiment for q² ? 14 fm^?2. However, there are two side benefits —a simple way to understand the d-wave contribution to the CFF, and a simple NΔ correlation function having a very good overlap with a more exact correlation.     

Dispersion relation calculation of the πNN form factor for one off-shell nucleon

We present a dispersion relation calculation of the πNN form factor in the kinematic region where one nucleon is off the mass shell and the pion is on its mass shell. The inclusion of πN inelasticity is shown to have a crucial effect on the results.     

First measurement of the 2H(6He,7Li)n angular distribution and proton spectroscopic factor in 7Li

The angular distribution of the ²H ( ⁶He,⁷Li n reaction was measured with a secondary ⁶He beam of 36.4MeV for the first time. The proton spectroscopic factor of ⁷Li ground state was extracted to be 0.42±0.06 by normalizing the calculational differential cross-sections with the distorted-wave Born approximation to the experimental data. It was discussed that the uncertainty of extracted spectroscopic factors from the one-nucleon transfer reactions induced by deuteron might be reduced by determining the volume integrals of imaginary optical potentials precisely.     

Approximate estimate of the form of molecular vibrations

Detailed polarized absorption and emission spectra are presented for anthracene and some of its methyl and methoxy derivatives in rigid solution at 77°K. PPP-SCF calculations show that no new states are introduced below 5 eV by the substitution. The observed effects of chemical substitution on state ordering, polarizations, and oscillator strength correlate quite well with the predictions of the PPP-SCF calculations. A vibrational analysis of the anthracene polarization spectra is carried out. In the near uv long-axis polarized absorption and fluorescence of anthracene, two vibronic origins are identified as a 1630 cm^?1b_1g molecular vibration and a weak 60 cm^?1b_g type of lattice vibration. All long-axis polarized structure in the near uv absorption can be assigned to Franck-Condon progressions built upon these vibronic origins in the ¹L_a band (which is electronically short-axis polarized). Differences in the spectral integrated transition intensity (oscillator strength) between the absorption and the emission reveal an additional long-axis component in the high energy region of the ¹L_a absorption which could be evidence for the hidden ¹L_b band in anthracene. However, there is no clear cut structural evidence for this state in the polarization spectrum. This hidden transition is made allowed by methoxy substitution. In the symmetric 2,3-dimethoxyanthracene, the ¹L_b band appears at 365 nm as a new transition. In 2-methoxyanthracene the ¹L_a and the ¹L_b are strongly mixed. The anomalous short-axis polarization of the ¹L_b band, predicted by the theory for 2-methoxyanthracene, is confirmed by the polarization data. Methoxy substitution also reveals new weak bands, located between the ¹L_b and ¹B_b bands, of B_1g and A_1g parentage, which are successfully predicted by the PPP-SCF calculations.     

On the calculation of charge densities in crystals

A general method is given for determining the spatial charge distribution of a filled electronic band using Bloch state charge distributions determined at very few k points. Formulae are given for several important cases.