Characterization of Jets in Relativistic Heavy Ion Collisions

Jet quenching is considered to be one of the signatures of the formation of quark gluon plasma. In order to investigate the jet quenching, it is necessary to detect jets produced in relativistic heavy ion collisions, determine their properties and compare those with the jets one obtains in hadron-hadron or $e^+-e^-$ collisions. In this work, we propose that calculation of flow parameters may be used to detect and characterize jets in relativistic heavy ion collisions.Comment: 18 pages, 4 figures, more discussions are added, to be published in Phys. Rev.

Neutrino Emissivity of Dense Stars

The neutrino emissivity of compact stars is investigated in this work. We consider stars consisting of nuclear as well as quark matter for this purpose. Different models are used to calculate the composition of nuclear and quark matter and the neutrino emissivity. Depending on the model under consideration, the neutrino emissivity of nuclear as well as quark matter varies over a wide range. We find that for nuclear matter, the direct URCA processes are allowed for most of the relativistic models without and with strange baryons, whereas for the nonrelativistic models this shows a strong dependence on the type of nuclear interaction employed. When the direct URCA processes are allowed, the neutrino emissivity of hadronic matter is larger than that of the quark matter by several orders of magnitude. We also find that the neutrino emissivity departs from $T^6$ behavior when the temperature is larger than the difference in the Fermi momenta of the particles, participating in the neutrino-producing reactions.Comment: Latex file. 5 figures available on request. accepted in Int. J. Mod. Phys.

Acceptance Dependence of Fluctuation in Particle Multiplicity

The effect of limiting the acceptance in rapidity on event-by-event multiplicity fluctuations in nucleus-nucleus collisions has been investigated. Our analysis shows that the multiplicity fluctuations decrease when the rapidity acceptance is decreased. We explain this trend by assuming that the probability distribution of the particles in the smaller acceptance window follows binomial distribution. Following a simple statistical analysis we conclude that the event-by-event multiplicity fluctuations for full acceptance are likely to be larger than those observed in the experiments, since the experiments usually have detectors with limited acceptance. We discuss the application of our model to simulated data generated using VENUS, a widely used event generator in heavy-ion collisions. We also discuss the results from our calculations in presence of dynamical fluctuations and possible observation of these in the actual data.Comment: To appear in Int. J. Mod. Phys.

EFFECT OF MURRAYA KOENIGII LEAVES EXTRACT ON GLUCONEOGENESIS AND GLYCOGENOLYSIS IN ISOLATED RAT HEPATOCYTES CULTURE

Objectives: The present study was aimed to investigate the in vitro activity of Murraya koenigii extracts through various carbohydrate metabolic pathways in the isolated rat hepatocyte models.Methods: Different doses of metformin, aqueous and methanol extracts of M. koenigii leaves were evaluated in the MTT, glucose, and glycogen content assays in the cultured in vitro rat hepatocytes.Results: The study showed that there was a significant increase in activity with respect to the increased concentration of extracts. Slight effect was observed in the isolated rat hepatocytes culture, M. koenigii leaves extract may exert cytoprotective and hypoglycemic action.Conclusion: It may be needed to determine the effect of ex vivo rat hepatocytes isolated from diabetic rats. Effects of the plant or isolated compounds on the genes expression of signaling pathways should be investigated in further studies

Dihyperon in Chiral Colour Dielectric Model

The mass of dihyperon with spin, parity $J^{\pi}=0^{+}$ and isospin $I = 0$ is calculated in the framework of Chiral colour dielectric model. The wave function of the dihyperon is expressed as a product of two colour-singlet baryon clusters. Thus the quark wave functions within the cluster are antisymmetric. Appropriate operators are then used to antisymmetrize inter-cluster quark wave functions. The radial part of the quark wavefunctions are obtained by solving the the quark and dielectric field equations of motion obtained in the Colour dielectric model. The mass of the dihyperon is computed by including the colour magnetic energy as well as the energy due to meson interaction. The recoil correction to the dihyperon mass is incorporated by Peierls-Yoccoz technique. We find that the mass of the dihyperon is smaller than the $\Lambda-\Lambda$ threshold by over 100 MeV. The implications of our results on the present day relativistic heavy ion experiments is discussed.Comment: LaTeX, 13 page

Recurrence Quantification Analysis and Principal Components in the Detection of Short Complex Signals

Recurrence plots were introduced to help aid the detection of signals in complicated data series. This effort was furthered by the quantification of recurrence plot elements. We now demonstrate the utility of combining recurrence quantification analysis with principal components analysis to allow for a probabilistic evaluation for the presence of deterministic signals in relatively short data lengths.Comment: 10 pages, 3 figures; Elsevier preprint, elsart style; programs used for analysis available for download at http://homepages.luc.edu/~cwebbe