2,033 research outputs found
Properties of excited states in QCD
The mass and leptonic decay constants of recently observed two new excited
states at LHC are studied within the QCD sum rules. Considering the
contributions of the ground and radially excited states, the mass and residues
of the excited states of pseudoscalar and vector mesons are calculated in the
framework of two different approaches of the QCD sum rules, namely, linear
combinations of the corresponding sum rules and its derivatives as well as QCD
sum rules with the incorporation of the least square fitting method. The
obtained results on mass and
are in good agreement with the
experimental data. Our predictions for the decay constants of these states are:
and , which can be checked at future experiments to be conducted at
the LHC. Comparison of our results with the predictions of the other approaches
on mass and residues is also presented.Comment: 11 pages, 4 figures Misprints are corrected and reference list has
been update
Exact solutions for vibrational levels of the Morse potential via the asymptotic iteration method
Exact solutions for vibrational levels of diatomic molecules via the Morse
potential are obtained by means of the asymptotic iteration method. It is shown
that, the numerical results for the energy eigenvalues of are all
in excellent agreement with the ones obtained before. Without any loss of
generality, other states and molecules could be treated in a similar way
transition form factors in light-cone sum rules
The form factors of transition is
calculated within the light-cone sum rules assuming that is
the first radial excitation of . The dependence of the
magnetic dipole , electric quadrupole , and
Coulomb quadrupole form factors are investigated. Moreover,
the dependence of the ratios and are studied. Finally,
our predictions on , , and
are compared with the results of other theoretical
approaches.Comment: 19 pages, 5 figure
Criterion for polynomial solutions to a class of linear differential equation of second order
We consider the differential equations y''=\lambda_0(x)y'+s_0(x)y, where
\lambda_0(x), s_0(x) are C^{\infty}-functions. We prove (i) if the differential
equation, has a polynomial solution of degree n >0, then \delta_n=\lambda_n
s_{n-1}-\lambda_{n-1}s_n=0, where \lambda_{n}=
\lambda_{n-1}^\prime+s_{n-1}+\lambda_0\lambda_{n-1}\hbox{and}\quad
s_{n}=s_{n-1}^\prime+s_0\lambda_{k-1},\quad n=1,2,.... Conversely (ii) if
\lambda_n\lambda_{n-1}\ne 0 and \delta_n=0, then the differential equation has
a polynomial solution of degree at most n. We show that the classical
differential equations of Laguerre, Hermite, Legendre, Jacobi, Chebyshev (first
and second kind), Gegenbauer, and the Hypergeometric type, etc, obey this
criterion. Further, we find the polynomial solutions for the generalized
Hermite, Laguerre, Legendre and Chebyshev differential equations.Comment: 12 page
Any -state solutions of the Hulth\'en potential by the asymptotic iteration method
In this article, we present the analytical solution of the radial
Schr\"{o}dinger equation for the Hulth\'{e}n potential within the framework of
the asymptotic iteration method by using an approximation to the centrifugal
potential for any states. We obtain the energy eigenvalues and the
corresponding eigenfunctions for different screening parameters. The wave
functions are physical and energy eigenvalues are in good agreement with the
results obtained by other methods for different values. In order to
demonstrate this, the results of the asymptotic iteration method are compared
with the results of the supersymmetry, the numerical integration, the
variational and the shifted 1/N expansion methods.Comment: 14 pages and 1 figur
The expansion of 300 CTG repeats in myotonic dystrophy transgenic mice does not induce sensory or motor neuropathy
Summary: Although many studies have been carried out to verify the involvement of the peripheral nervous system (PNS) in dystrophia myotonica (DM1) patients, the results remain controversial. The generation of DM1 transgenic mice displaying the human DM1 phenotype provides a useful tool to investigate the type and incidence of structural abnormalities in the PNS. In the present study, the morphological and morphometric analysis of semi-thin sections of sciatic and sural nerves, lumbar dorsal root ganglia (DRG) and lumbar spinal cords revealed that in DM1 transgenic mice carrying 300 CTG repeats, there is no change in the number and diameter of myelinated axons compared to wild type. Only a non-significant reduction in the percentage of thin myelinated axons was detected in electron micrographs of ultra-thin sciatic nerve sections. Analysis of the number of neurons did not reveal a loss in number of either sensory neurons in the lumbar DRG or motor neurons in the lumbar spinal cord in these DM1 mice. Furthermore, in hind limb muscle sections, stained with a neurofilament antibody and α-bungarotoxin, the intramuscular axon arborization appeared normal in DM1 mice and undistinguishable from that in wild-type mice. Moreover, in DM1 mice, there was no irregularity in the structure or an increase in the endplate area. Also statistical analysis did not show an increase in endplate density or in the concentration of acetylcholine receptors. Altogether, these results suggest that 300 CTG repeats are not sufficient to induce axonopathy, demyelination or neuronopathies in this transgenic mouse mode
Magnetothermal instabilities in magnetized anisotropic plasmas
Using the transport equations for an ideal anisotropic collisionless plasma
derived from the Vlasov equation by the 16-moment method, we analyse the
influence of pressure anisotropy exhibited by collisionless magnetized plasmas
on the magnetothermal (MTI) and heat-flux-driven buoyancy (HBI) instabilities.
We calculate the dispersion relation and the growth rates for these
instabilities in the presence of a background heat flux and for configurations
with static pressure anisotropy, finding that when the frequency at which heat
conduction acts is much larger than any other frequency in the system (i.e.
weak magnetic field) the pressure anisotropy has no effect on the MTI/HBI,
provided the degree of anisotropy is small. In contrast, when this ordering of
timescales does not apply the instability criteria depend on pressure
anisotropy. Specifically, the growth time of the instabilities in the
anisotropic case can be almost one order of magnitude smaller than its
isotropic counterpart. We conclude that in plasmas where pressure anisotropy is
present the MTI/HBI are modified. However, in environments with low magnetic
fields and small anisotropy such as the ICM the results obtained from the
16-moment equations under the approximations considered are similar to those
obtained from ideal MHD.Comment: v3: 16 pages, 2 figures, fixed typos, added references and a final
note on related wor
Prolonging Vase Life of Carnation Flowers Using Natural Essential Oils and its Impact on Microbial Profile of Vase Solutions
Abstract: This experiment was conducted during the two summer seasons; 2008 and 2009. Two cultivars of Dianthus caryphyllus L. were used; Farida and Madam Collate. Four essential oil treatments were used versus two controls; Tap water and 8-Hydroxyquinoline (8-HQ). These essential oils were extracted from mandarin, coriander, dill and clove. The maximum vase-life over the two seasons was recorded with dill oil followed by coriander in cv. Farida and with 8-HQ in cv. Madam Collate. The essential oils treatments showed accumulative significant reduction percentages in flower fresh weight, which increased by decreasing the used oil concentrations. The accumulative reduction percentage in flower fresh weight and the average flower dry weight showed negative significant correlation coefficients. The relative increased percentages in net water uptake were 10.93 and 7.95% in 8-HQ for both cultivars. The net water uptake had the greatest values with those flowers kept in solution containing dill followed by clove oils in cv. M adam Collate and by mandarin oil in cv. Farida. The highest positive correlation coefficient was recorded between vase life and net water uptake. The highest pH value was observed in vase containing tap water for both cultivars. In comparison, due to different treatments application, the pH values were significantly changed to a fairly acidic. These treatments were ranked, in this respect, at descending order as follows; dill oil, 8-HQ, mandarin, coriander and clove with both cultivars. The highest mean count of total sporeforming bacteria was recorded in the tap water vase solutions, while the lowest counts were with coriander oil. In vase solution containing dill oil, the log count of molds decreased as the dose concentration increased. The same trend was observed in cv. Madam Collate during the seasons. Counts of cellulose decomposing microorganisms were increased by extending the life of the carnation cut flowers in the vase solutions. All the examined preservatives, in particular 8-HQ, and the oils of dill, clove and coriander greatly suppressed proliferation of cellulose decomposers and resulted in flower densities compared with control solutions. The anatomical study indicated that, cv. Farida flower stalks greatly severe from more exposure to microorganisms attack in vase solution, especially cellulose decomposing microorganisms which penetrate tissues as lethal and blockage parasites. These negative influences on cv. Farida could be an evidence for explaining its rapid senescence and the longevity of the flowers of cv. Madam Collate
An Axiomatic Setup for Algorithmic Homological Algebra and an Alternative Approach to Localization
In this paper we develop an axiomatic setup for algorithmic homological
algebra of Abelian categories. This is done by exhibiting all existential
quantifiers entering the definition of an Abelian category, which for the sake
of computability need to be turned into constructive ones. We do this
explicitly for the often-studied example Abelian category of finitely presented
modules over a so-called computable ring , i.e., a ring with an explicit
algorithm to solve one-sided (in)homogeneous linear systems over . For a
finitely generated maximal ideal in a commutative ring we
show how solving (in)homogeneous linear systems over can be
reduced to solving associated systems over . Hence, the computability of
implies that of . As a corollary we obtain the computability
of the category of finitely presented -modules as an Abelian
category, without the need of a Mora-like algorithm. The reduction also yields,
as a by-product, a complexity estimation for the ideal membership problem over
local polynomial rings. Finally, in the case of localized polynomial rings we
demonstrate the computational advantage of our homologically motivated
alternative approach in comparison to an existing implementation of Mora's
algorithm.Comment: Fixed a typo in the proof of Lemma 4.3 spotted by Sebastian Posu
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