37 research outputs found
The pseudo scalar form factor of the nucleon, the sigma-like term, and the amplitude for charged pion electro-production near threshold
The pseudo scalar form factor, which represents the pseudo scalar quark
density distribution due to finite quark masses on the nucleon, is shown to
manifest itself with the induced pseudo scalar form factor in the
amplitude for the charged pion electro-production. Both form factors show their
own peculiar momentum dependence. Under the approximation on which the
Goldberg-Treimann relation holds, a sum of both form factors' contributions
accounts for the t-channel contribution in the charged pion electro-production
near threshold.Comment: 10 page
Consistent Linearized Gravity in Brane Backgrounds
A globally consistent treatment of linearized gravity in the Randall-Sundrum
background with matter on the brane is formulated. Using a novel gauge, in
which the transverse components of the metric are non-vanishing, the brane is
kept straight. We analyze the gauge symmetries and identify the physical
degrees of freedom of gravity. Our results underline the necessity for
non-gravitational confinement of matter to the brane.Comment: 15 page
Tricritical gravity waves in the four-dimensional generalized massive gravity
We construct a generalized massive gravity by combining quadratic curvature
gravity with the Chern-Simons term in four dimensions. This may be a candidate
for the parity-odd tricritical gravity theory. Considering the AdS vacuum
solution, we derive the linearized Einstein equation, which is not similar to
that of the three dimensional (3D) generalized massive gravity. When a
perturbed metric tensor is chosen to be the Kerr-Schild form, the linearized
equation reduces to a single massive scalar equation. At the tricritical points
where two masses are equal to -1 and 2, we obtain a log-square wave solution to
the massive scalar equation. This is compared to the 3D tricritical generalized
massive gravity whose dual is a rank-3 logarithmic conformal field theory.Comment: 17 pages, 1 figure, version to appear in EPJ
Isothermal Plasma Wave Properties of the Schwarzschild de-Sitter Black Hole in a Veselago Medium
In this paper, we study wave properties of isothermal plasma for the
Schwarzschild de-Sitter black hole in a Veselago medium. We use ADM 3+1
formalism to formulate general relativistic magnetohydrodynamical (GRMHD)
equations for the Schwarzschild de-Sitter spacetime in Rindler coordinates.
Further, Fourier analysis of the linearly perturbed GRMHD equations for the
rotating (non-magnetized and magnetized) background is taken whose determinant
leads to a dispersion relation. We investigate wave properties by using
graphical representation of the wave vector, the refractive index, change in
refractive index, phase and group velocities. Also, the modes of wave
dispersion are explored. The results indicate the existence of the Veselago
medium.Comment: 24 pages, 12 figures, accepted for publication in Astrophys. Space
Sci. arXiv admin note: text overlap with arXiv:1101.0884 and arxiv:1007.285
An Isobaric Model for Kaon photoproduction
The kaon photoproduction is analyzed up to =2.0 GeV by
using an isobaric model based on effective Lagrangians and by taking a cross
symmetry into account. Both {\it pseudovector} and {\it pseudoscalar} couplings
for kaon-baryon-baryon (baryon spin=1/2) interactions are considered with form
factors. A vector meson(), an axial vector meson(),
nucleon resonances(), and hyperon resonances() are treated as
participating particles. By determining unknown coupling constants through a
systematic fitting of the differential cross section, the total cross section,
the single polarization observable, and the radiative kaon capture branching
ratio to their experimental data, we find out a simple model which reproduces
all the experimental data well.Comment: 48 pages, 7 figure
EC3-A modern telecommunications matrix for cervical cancer prevention in Zambia
Objectives.: Low physician density, undercapacitated laboratory infrastructures, and limited resources are major limitations to the development and implementation of widely accessible cervical cancer prevention programs in sub-Saharan Africa. Materials and methods.: We developed a system operated by nonphysician health providers that used widely available and affordable communication technology to create locally adaptable and sustainable public sector cervical cancer prevention program in Zambia, one of the world's poorest countries. Results.: Nurses were trained to perform visual inspection with acetic acid aided by digital cervicography using predefined criteria. Electronic digital images (cervigrams) were reviewed with patients, and distance consultation was sought as necessary. Same-visit cryotherapy or referral for further evaluation by a gynecologist was offered. The Zambian system of "electronic cervical cancer control" bypasses many of the historic barriers to the delivery of preventive health care to women in low-resource environments while facilitating monitoring, evaluation, and continued education of primary health care providers, patient education, and medical records documentation. Conclusions.: The electronic cervical cancer control system uses appropriate technology to bridge the gap between screening and diagnosis, thereby facilitating the conduct of "screen-and-treat" programs. The inherent flexibility of the system lends itself to the integration with future infrastructures using rapid molecular human papillomavirus-based screening approaches and wireless telemedicine communications
Search for CP violation in D0 and D+ decays
A high statistics sample of photoproduced charm particles from the FOCUS
(E831) experiment at Fermilab has been used to search for CP violation in the
Cabibbo suppressed decay modes D+ to K-K+pi+, D0 to K-K+ and D0 to pi-pi+. We
have measured the following CP asymmetry parameters: A_CP(K-K+pi+) = +0.006 +/-
0.011 +/- 0.005, A_CP(K-K+) = -0.001 +/- 0.022 +/- 0.015 and A_CP(pi-pi+) =
+0.048 +/- 0.039 +/- 0.025 where the first error is statistical and the second
error is systematic. These asymmetries are consistent with zero with smaller
errors than previous measurements.Comment: 12 pages, 4 figure
A measurement of lifetime differences in the neutral D-meson system
Using a high statistics sample of photoproduced charm particles from the
FOCUS experiment at Fermilab, we compare the lifetimes of neutral D mesons
decaying via D0 to K- pi+ and K- K+ to measure the lifetime differences between
CP even and CP odd final states. These measurements bear on the phenomenology
of D0 - D0bar mixing. If the D0 to K-pi+ is an equal mixture of CP even and CP
odd eigenstates, we measure yCP = 0.0342 \pm 0.0139 \pm 0.0074.Comment: 15 pages, 5 figure
Measurements of the Sigma_c^0 and Sigma_c^{++} Mass Splittings
Using a high statistics sample of photoproduced charmed particles from the
FOCUS experiment at Fermilab (FNAL-E831), we measure the mass splittings of the
charmed baryons Sigma_c^0 and Sigma_c^{++}. We find M(Sigma_c^0 - Lambda_c^+) =
167.38 +/- 0.21 +/- 0.13 MeV/c^2 and M(Sigma_c^++ - Lambda_c^+) = 167.35 +/-
0.19 +/- 0.12 MeV/c^2 with samples of 362 +/- 36 and 461 +/- 39 events,
respectively. We measure the isospin mass splitting M(Sigma_c^++ - Sigma_c^0)
to be -0.03 +/- 0.28 +/- 0.11 Mev/c^2. The first errors are statistical and the
second are systematic.Comment: 10 pages, 2 figure
Coulomb sum rule in the quasielastic region using various nuclear models
© 2022 American Physical Society.We calculate the Coulomb sum rule of inclusive (e,e′) reactions from C12, Ca40, Fe56, and Pb208 in the quasielastic region using various relativistic single-particle models, which include the relativistic Hartree, the nonlinear sigma, the quark-meson-coupling, and the chiral quark-meson-coupling models. We investigate the cross sections calculated in these nuclear models by comparing them with Bates, Saclay, and SLAC data for three-momentum transfer q ranging from 300 to 500 MeV/c. We find that the extracted longitudinal structure functions are not so sensitive to the nuclear model but the transverse structure functions strongly depend on the model. We report that, for three-momentum transfer q>400 MeV/c, the values of the Coulomb sum rule from various nuclear models except the Hartree model are greater than 1.11Nsciescopu