Products of rough finite state machines

In this paper, we introduce the concept of several products of rough finite state machines. We establish their relationships through coverings and investigate some algebraic properties for these products

Hot and Dense Hadron Gas (HG): A New Excluded-volume approach

We formulate a thermodynamically consistent equation of state (EOS), based on excluded-volume approach, for a hot, dense hadron gas (HG). We calculate various thermodynamical quantities of HG and various hadron ratios and compare our model results with the results of other excluded-volume models and experimental data. We also calculate various transport coefficients such as $\eta/s$ etc. and compare them with other HG model results. Furthermore, we test the validity of our model in getting the rapidity spectra of various hadrons and the effect of flow on them is investigated by matching our predictions with the experimental data.Comment: 5 pages, 4 figures, To be published in proceedings of QGP Meet-2012 held at VECC, Kolkata, Indi

Magnetic Susceptibility of NiO Nanoparticles

Nickel oxide nanoparticles of different sizes are prepared and characterized by x-ray diffraction and transmission electron microscopy. A.C. susceptibility measurements as a function of temperature are carried out for various particle sizes and frequencies. We find that the behavior of the system is spin glass like.Comment: 16 pages, 5 figure

Paramagnetic to Superparamagnetic Transition in Ni(OH)_2 Nanoparticles

We report the temperature and field dependence of dc magnetization on sol-gel prepared nanoparticles of Ni(OH)_2. At higher temperature the system is found to behave as a paramagnet while we find evidence for superparamagnetic blocking at low temperature. The system shows a paramagnet-superparamagnet transition and we discuss the underlying mechanism.Comment: 4 pages, 7 figures, a floating reference remove

Further Evidences for Spin Glass like behavior in NiO nanoparticles

Nickel oxide nanoparticles are prepared by a sol gel method and characterized by x-ray diffraction and transmission electron microscope. Here we present measurements on temperature and field dependence of magnetization and time dependence of thermoremanent magnetization. Our conclusion based on these measurements is that the system shows spin glass like behavior.Comment: 5 pages, 3 figure

Improved transfer efficiency with pulsed atom transfer between two magneto-optical traps

In our double magneto-optical trap (MOT) setup containing a vapor chamber MOT (VC-MOT) and an ultra high vacuum MOT (UHV-MOT) for $^{87}$Rb atoms, we find that transfer of atoms from VC-MOT to UHV-MOT can be enhanced by employing a pulsed VC-MOT loading followed by a pulsed push beam, as compared to that obtained by focusing a continuous wave (CW) push beam on a continuously loaded VC-MOT. By choosing appropriately the VC-MOT duration and push beam duration, the number of atoms in UHV-MOT was $\sim$3-times the number obtained with a continuous VC-MOT and a CW push beam of optimized power. The processes affecting the pulsed transfer have been studied.Comment: 10 pages, 4 figure

Coherent Lateral Motion of Penumbral Filaments during X-class Flare

The high-resolution pictures of the solar photosphere from space based 50 cm Solar Optical Telescope (SOT) on-board Hinode spacecraft, are now routinely observed. Such images of a delta-sunspot in NOAA 10930 were obtained by Hinode during 13 December 2006 while a X-class flare occurred in this active region. Two bright ribbons were visible even in white light and G-band images apart from chromospheric Ca II H images. We register the sunspot globally using cross-correlation technique and analyse local effects during flare interval. We find that during flare the penumbral filaments show lateral motion. Also, we locate two patches, one in either polarity, which show converging motion towards the polarity inversion line (PIL). In Ca II H images we find kernel with pre-flare brightening which lie along the PIL.Comment: 4 pages (ASP style), 2 figures, for the proceedings of "Hinode-3:The third Hinode Science Meeting" Toky

Description of Hot and Dense Hadron Gas Properties in a New Excluded-Volume model

A new equation of state for a hot and dense hadron gas (HG) is obtained where the finite hard-core size of baryons has been incorporated in a thermodynamically consistent formulation of excluded volume correction. Our model differs from other existing approaches on the following points. We assign a hard-core volume only to each baryon and mesons though possess a small volume but they can fuse and interpenetrate into one another. Use of the full quantum statistics is made in obtaining the grand canonical partition function where excluded-volume correction has been incorporated by explicitly integrating over volume. We thus find that the new model works even for the cases of extreme temperatures and/or densities where most of other approaches fail. The model does not violate causality even at extreme densities. The temperature and density dependence of various thermodynamical quantities, e.g. pressure, baryon density, entropy and energy density compare well with the results of other microscopic HG models. After suitable parametrization of the centre-of-mass energy in terms of temperature and baryon chemical potential, we explore some new freeze-out criteria which exhibit full independence of the collision energy and of the structures of the colliding nuclei. We further demonstrate the suitability of our model in explaining various experimental results of the multiplicity-ratios of various particles and their antiparticles. Finally, we use our excluded-volume model to obtain the transport behaviour of the hot and/or dense HG such as shear viscosity to entropy ratio, speed of sound etc. and compare the results with earlier calculations.Comment: 34 pages, 25 figures, 1 tabl

On Locating the Critical End Point in QCD Phase Diagram

We use the available two different self-consistent formulations of quasiparticle models and extend their applications for the description of quark gluon plasma (QGP) at non-vanishing baryon chemical potentials. The thermodynamical quantities calculated from these models are compared with the values obtained from lattice simulations and a good agreement between theoretical calculations and lattice QCD data suggests that the values of the parameters used in the paper are consistent. A new equation of state (EOS) for a gas of extended baryons and pointlike mesons is presented here which incorporates the repulsive hard-core interactions arising due to geometrical size of baryons. A first order deconfining phase transition is constructed using Gibb's equilibrium criteria between the hadron gas EOS and quasiparticle model EOS for the weakly interacting quark matter. This leads to an interesting finding that the phase transition line ends at a critical end point beyond which a crossover region exists in the phase diagram.Comment: 4 pages, 1 figure, talk given by P. K. Srivastava at 6th ICPAQGP-2010, Goa, India (Dec. 06-10, 2010). Submitted to Nuclear Physics

Upsilon suppression at energies available at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider in a modified color screening scenario

The suppression of heavy quarkonia e.g. $J/\psi$, $\Upsilon$ etc. is considered as a suitable probe to identify the nature of the matter created in heavy ion collisions. Recently we have presented a modified colour screening model for $J/\psi$ suppression in the quark gluon plasma (QGP) using quasiparticle model as the equation of state. In this paper, we extend our model to calculate the anomalous suppression of various states of $\Upsilon$ arising due to QGP medium alone. We obtain the suppression patterns of different bottomonia states with respect to centrality at various available collision energies and compare them with the available experimental data.Comment: 7 pages, 7 figures, Revised version accepted for publication in Physical Review C. arXiv admin note: substantial text overlap with arXiv:1208.479