Parton Distributions in Impact Parameter Space

Fourier transform of the generalized parton distributions (GPDs) at zero skewness with respect to the transverse momentum transfer gives the distribution of partons in the impact parameter space. We investigate the GPDs as well as the impact parameter dependent parton distributions (ipdpdfs) by expressing them in terms of overlaps of light front wave functions (LFWFs) and present a comparative study using three different model LFWFs.Comment: 13 pages, 6 figure

Magnetic moments of the low-lying JP= 1/2−J^P=\,1/2^-, 3/2−3/2^- Λ\Lambda resonances within the framework of the chiral quark model

The magnetic moments of the low-lying spin-parity $J^P=$ $1/2^-$, $3/2^-$ $\Lambda$ resonances, like, for example, $\Lambda(1405)$ $1/2^-$, $\Lambda(1520)$ $3/2^-$, as well as their transition magnetic moments, are calculated using the chiral quark model. The results found are compared with those obtained from the nonrelativistic quark model and those of unitary chiral theories, where some of these states are generated through the dynamics of two hadron coupled channels and their unitarization

Chiral constituent quark model and the coupling strength of eta'

Using the latest data pertaining to \bar u-\bar d asymmetry and the spin polarization functions, detailed implications of the possible values of the coupling strength of the singlet Goldstone boson \eta' have been investigated in the \chiCQM with configuration mixing. Using \Delta u, \Delta_3, \bar u-\bar d and \bar u/\bar d, the possible ranges of the coupling parameters a, \alpha^ 2, \beta^ 2 and \zeta^ 2, representing respectively the probabilities of fluctuations to pions, K, \eta and \eta^{'}, are shown to be 0.10 \lesssim a \lesssim 0.14, 0.2\lesssim \alpha \lesssim 0.5, 0.2\lesssim \beta \lesssim 0.7 and 0.10 lesssim |\zeta| \lesssim 0.70. To constrain the coupling strength of \eta', detailed fits have been obtained for spin polarization functions, quark distribution functions and baryon octet magnetic moments corresponding to the following sets of parameters: a=0.1, \alpha=0.4, \beta=0.7, |\zeta|=0.65 (Case I); a=0.1, \alpha=0.4, \beta=0.6, |\zeta|=0.70 (Case II); a=0.14, \alpha=0.4, \beta=0.2, \zeta=0 (Case III) and a=0.13, \alpha=\beta=0.45, |\zeta|=0.10 (Case IV). Case I represents the calculations where a is fixed to be 0.1, in accordance with earlier calculations, whereas other parameters are treated free and the Case IV represents our best fit. The fits clearly establish that a small non-zero value of the coupling of \eta' is preferred over the higher values of \eta' as well as when \zeta=0, the latter implying the absence of \eta' from the dynamics of \chiCQM. Our best fit achieves an overall excellent fit to the data, in particular the fit for \Delta u, \Delta d, \Delta_8 as well as the magnetic moments \mu_{n}, \mu_{\Sigma^-}, \mu_{\Sigma^+} and \mu_{\Xi^-} is almost perfect, the \mu_{\Xi^-} being a difficult case for most of the similar calculations.Comment: 8 RevTeX pages, 2 Tables, Revised version to appear in Int.J.Mod.Phys

Service performance of refractories in connection with pusher reheating furnaces in Bhilai Steel Plant

Bhilai Steel Plant comprises of three finishing mills, which are equipped with continuous pusher reheating furnaces to heat blooms & billets from the blooming & billet mill at 2.5 M. T. stage. Reheating furnaces of rail & structural mill and merchant mill are of same design with three zones having 20 burners in each furnace (7 burners in top & bottom zone & 6 burners in soaking zone). The wire rod mill has got only one reheating furnace with 2 zones having 14 burners in each zone

Oscillation of Higher-Order Neutral-Type Periodic Differential Equations with Distributed Arguments

We derive oscillation criteria for general-type neutral differential equations [x(t) +αx(t− τ) +βx(t +τ)](n) = δ b ax(t − s)dsq1(t,s) + δ d c x(t + s)dsq2(t,s) = 0, t ≥ t0, where t0 ≥ 0, δ = ±1, τ > 0, b>a ≥ 0, d>c ≥ 0, α and β are real numbers, the functions q1(t,s) : [t0,∞) × [a,b] → R and q2(t,s):[t0,∞) × [c,d] → R are nondecreasing in s for each fixed t, and τ is periodic and continuous with respect to t for each fixed s. In certain special cases, the results obtained generalize and improve some existing ones in the literature. Copyright © 2007 R. S. Dahiya and A. Zafer. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedPublisher's Versio

An experimental study on the effect of isoniazid on the efficacy, plasma concentration and toxicity of paracetamol in Albino rats

Background: Paracetamol is used for symptomatic treatment of fever and pain with isoniazid and other anti-tubercular drugs in patients of tuberculosis. Literature has conflicting data regarding their interaction. Some studies show that isoniazid increases oxidative metabolism of paracetamol whereas some other suggest that isoniazid has an inhibitory effect. The present study was conducted to find out the possible interaction between paracetamol and isoniazid.Methods: The study was undertaken on Wistar strain of Albino rats. Group I and Group II animals were treated with paracetamol (500 mg/kg) and the combination of paracetamol (500 mg/kg) and isoniazid (30 mg/kg) respectively for 2 months. Blood samples were taken before and during the study for biochemical and histopathological studies of liver and renal functions and plasma paracetamol concentration was also evaluated.Results: Isoniazid decreased the plasma paracetamol concentration without affecting its analgesic activity. However, the hepatotoxic and nephrotoxic effects of paracetamol were found to be further aggravated by isoniazid co-administration.Conclusion: Isoniazid potentiates the hepatotoxic and nephrotoxic effects of paracetamol possibly due to hepatic enzyme induction by isoniazid

Mechanism of single-spin asymmetries generation in the inclusive hadron processes

We discuss a nonperturbative mechanism for generation of the single-spin asymmetries in hadron interactions. It is based on the chiral quark model combined with unitarity and impact parameter picture and provides explanation for the experimental regularities observed under the measurements of the spin asymmetries.Comment: 20 pages, 7 figure

Chiral symmetry in linear Sigma model in magnetic environment

We study the chiral symmetry structure in a linear sigma model with fermions in the presence of an external, uniform magnetic field in the 'effective potential' approach at the one loop level. We also study the chiral phase transition as a function of density in the core of magnetized neutron stars.Comment: LaTex2e file with six postscript figures. journal ref: Physical Review D 62 (2000) 02502

Octet magnetic moments and the Coleman-Glashow sum rule violation in the chiral quark model

Baryon octet magnetic moments when calculated within the chiral quark model, incorporating the orbital angular momentum as well as the quark sea contribution through the Cheng-Li mechanism, not only show improvement over the non relativistic quark model results but also gives a non zero value for the right hand side of Coleman-Glashow sum rule. When effects due to spin-spin forces between constituent quarks as well as `mass adjustments' due to confinement are added, it leads to an excellent fit for the case of p, \Sigma^+, \Xi^o and violation of Coleman-Glashow sum rule, whereas in almost all the other cases the results are within 5% of the data.Comment: 5 RevTeX pages, accepted for publication in PRD(Rapid Communication