32 research outputs found
The Dirac form factor predicts the Pauli form factor in the Endpoint Model
We compute the momentum-transfer dependence of the proton Pauli form factor
in the endpoint overlap model. We find the model correctly reproduces
the scaling of the ratio of with the Dirac Form factor observed
at the Jefferson Laboratory. The calculation uses the leading-power, leading
twist Dirac structure of the quark light-cone wave function, and the same
endpoint dependence previously determined from the Dirac form factor .
There are no parameters and no adjustable functions in the endpoint model's
prediction for . The model's predicted ratio
is quite insensitive to the endpoint wave function, which explains why the
observed ratio scales like down to rather low momentum transfers. The
endpoint model appears to be the only comprehensive model consistent with all
form factor information as well as reproducing fixed-angle proton-proton
scattering at large momentum transfer. Any one of the processes is capable of
predicting the others.Comment: 12 pages, 3 figure
Pressure dependent mechanical and thermodynamical properties of Hg
The mechanical, thermodynamical and elastic properties of Hg0.91Mn0.09Te compound are calculated by formulating an effective interionic interaction potential. This potential consists of the long-range Coulomb, three body force parameter, the Hafemeister and Flygare type short-range overlap repulsion extended upto the second neighbor ions and the van der Waals (vdW) interaction. The estimated values of phase transition pressure have revealed reasonably good agreement with the available experimental data on the phase transition pressure Pt = 11.5 GPa and the vast volume discontinuity in pressure-volume (PV) phase diagram indicate the structural phase transition from zincblende (B3) to rock salt (B1) structure. Later on, the Poisson's ratio ν, the ratio RS/B of S (Voigt averaged
shear modulus) over B (bulk modulus), elastic anisotropy parameter, elastic wave velocity, average wave velocity and Debye temperature as functions of pressure is calculated. From Poisson's ratio and the ratio RS/B it is inferred that Hg0.91Mn0.09Te is brittle in nature in both B3 phase
and B1 phase. To our knowledge this is the first quantitative theoretical prediction of the pressure dependence of ductile (brittle) nature of Hg0.91Mn0.09Te compounds and still awaits experimental confirmations