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Nucleon Properties at Finite Temperature in the Extended Quark-Sigma Model
M. Abu-Shady,
A. K. Abu-Nab
Issue:
Volume 2, Issue 2, March 2014
Pages:
46-51
Received:
30 January 2014
Published:
10 March 2014
Abstract: Hadron properties are studied at hot medium using the quark sigma model. The quark sigma model is extended to include eighth-order of mesonic interactions based on some aspects of quantum chromodynamic (QCD) theory. The extended effective potential tends to the original effective potential when the coupling between the higher order mesonic interactions equal to zero. The field equations have been solved in the mean-field approximation by using the extended iteration method. We found that the nucleon mass increases with increasing temperature and the magnetic moments of proton and neutron increase with increasing temperature. A comparison is presented with recent previous works and other models. We conclude that higher-order mesonic interactions play an important role in changing the behavior of nucleon properties at finite temperature. In addition, the deconfinement phase transition is satisfied in the present model.
Abstract: Hadron properties are studied at hot medium using the quark sigma model. The quark sigma model is extended to include eighth-order of mesonic interactions based on some aspects of quantum chromodynamic (QCD) theory. The extended effective potential tends to the original effective potential when the coupling between the higher order mesonic interact...
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Differential Cross Section Comparison Calculated from Kalbach and Iwmoto-Harada Models for Alpha Emission in Pre-equilibrium Region
Shafik Shaker Shafik,
Gaith Naima Flaiah,
Akram Mohammed Ali
Issue:
Volume 2, Issue 2, March 2014
Pages:
52-55
Received:
5 January 2014
Published:
20 March 2014
Abstract: α-cluster cross section production by proton/neutron induced reactions was calculated at different energies using Kalbach PRECO6 program and an analysis in the framework of pre-equilibrium exciton model made with Iwamoto-Harada [IH] model depend on pickup mechanism. Comparison with our calculation give remarkable agreement with experimental data. The cross section have been estimated for the targets 54Fe, 63Cu, 120Sn with different energies.
Abstract: α-cluster cross section production by proton/neutron induced reactions was calculated at different energies using Kalbach PRECO6 program and an analysis in the framework of pre-equilibrium exciton model made with Iwamoto-Harada [IH] model depend on pickup mechanism. Comparison with our calculation give remarkable agreement with experimental data. T...
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Studies on the Effective Physical Parameters for Chirp Reduction in Optical Injection Locked Semiconductor Lasers
S. N. Hosseinimotlagh,
M. Nikravesh,
H. Molaei,
M. Pezeshkian
Issue:
Volume 2, Issue 2, March 2014
Pages:
56-60
Received:
5 March 2014
Published:
30 March 2014
Abstract: In optical injection locking, the light from one laser (master laser)is injected into another laser slave laser. The injected light causes changes in the slave laser characteristics, and it can lock the slave laser lasing frequency to the ML lasingfrequency. The locking characteristics are determined by theamount of injected power and thefrequency difference between the master laser and slave laser.In this paper, the chirp of injection-locked semiconductor lasers has been theoretically investigated. First, chirpcharacteristics of semiconductor lasers are described. The chirp to power ratio has been calculated with including opticalinjection effect in lasers rate equation. Then, the effects of phase difference between master and slave laser and modulation frequency on chirp to power ratio are evaluated. The results of calculations show that the effect of phasedifference can be neglected, but optical injection, line width enhancement factor, and detuningfrequency have an effective role in chirp reduction of semiconductor lasers.
Abstract: In optical injection locking, the light from one laser (master laser)is injected into another laser slave laser. The injected light causes changes in the slave laser characteristics, and it can lock the slave laser lasing frequency to the ML lasingfrequency. The locking characteristics are determined by theamount of injected power and thefrequency ...
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Applications of Statistical Physics Distributions to Several Types of Income
Elvis Oltean,
Fedor V. Kusmartsev
Issue:
Volume 2, Issue 2, March 2014
Pages:
61-66
Received:
16 March 2014
Accepted:
9 April 2014
Published:
20 April 2014
Abstract: This paper explores several types of income which have not been explored so far by authors who tackled income and wealth distribution using Statistical Physics. The main types of income we plan to analyze are income before redistribution (or gross income), income of retired people (or pensions), and income of active people (mostly wages). The distributions used to analyze income distributions are Fermi-Dirac distribution and polynomial distribution (as this is present in describing the behavior of dynamic systems in certain aspects). The data we utilize for our analysis are from France and the UK. We find that both distributions are robust in describing these varieties of income. The main finding we consider to be the applicability of these distributions to pensions, which are not regulated entirely by market mechanisms
Abstract: This paper explores several types of income which have not been explored so far by authors who tackled income and wealth distribution using Statistical Physics. The main types of income we plan to analyze are income before redistribution (or gross income), income of retired people (or pensions), and income of active people (mostly wages). The distr...
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Fast Algorithms for Simulating Chiral Fermions in U(1) Lattice Gauge Theory
Dafina. Xhako,
Artan. Boriçi
Issue:
Volume 2, Issue 2, March 2014
Pages:
67-72
Received:
6 March 2014
Accepted:
11 April 2014
Published:
20 April 2014
Abstract: Lattice QCD with chiral fermions are extremely computationally expensive, but on the other hand provides an accurate tool for studying the physics of strong interactions. Since the truncated overlap variant of domain wall fermions are equivalent to overlap fermions in four dimensions at any lattice spacing, in this paper we have used domain wall fermions for our simulations. The physical information of lattice QCD theory is contained in quark propagators. In practice computing quark propagator in lattice is an inversion problem of the Dirac operator matrix representing this quarks. In order to develop fast inversion algorithms we have used overlap solvers in two dimensions. Lattice QED theory with U(1) group symmetry in two dimensional space-times dimensions has always been a testing ground for algorithms. By the other side, motivated by our previews work that the two-grid algorithm converge faster than the standard iterative methods for overlap inversion but not for all quark masses, we thought to test this idea in less dimensions such as U(1) gauge theory. Our main objective of this paper it is to implement and develop the idea of a two level algorithm in a new algorithm coded in QCDLAB. This implementation is presented in the preconditioned GMRESR algorithm, as our new contribution in QCDLAB package. The preconditioned part of our algorithm, different from the one of [18], is the approximation of the overlap operator with the truncated overlap operator with finite N3 dimension. We have tested it for 100 statistically independent configurations on 32 x 32 lattice background U(1) field at coupling constant β=1 and for different bare quark masses mq = [0.5, 0.45, 0.4, 0.35, 0.3, 0.25, 0.2, 0.15, 0.1]. We have compared the convergence history of the preconditioned GMRESR residual norm with another overlap inverter of QCDLAB as an optimal one, such as SHUMR. We have shown that our algorithm converges faster than SHUMR for different quark masses. Also, we have demonstrated that it saves more time for light quarks compared to SHUMR algorithm. Our algorithm is approximately independent from the quark mass. This is a key result in simulations with chiral fermions in lattice theories. By the other side, if we compare the results of [18] for quark mass 0.1 in SU(3), results that our chosen preconditioned saves a factor of 2 but in U(1). Our next step is to test this algorithm in SU(3) and to adopt it in parallel
Abstract: Lattice QCD with chiral fermions are extremely computationally expensive, but on the other hand provides an accurate tool for studying the physics of strong interactions. Since the truncated overlap variant of domain wall fermions are equivalent to overlap fermions in four dimensions at any lattice spacing, in this paper we have used domain wall fe...
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