In the present paper, we investigate the power-law behaviour of the magnetic field spectra in the Earths magnetosheath region using Cluster spacecraft data under solar minimum condition. The power spectral density of the magnetic field data and spect
ral slopes at various frequencies are analysed. Propagation angle and compressibility are used to test the nature of turbulent fluctuations. The magnetic field spectra have the spectral slopes between -1.5 to 0 down to spatial scales of 20 ion gyroradius and show clear evidence of a transition to steeper spectra for small scales with a second power-law, having slopes between -2.6 to -1.8. At low frequencies, f_sc<0.3f_ci(where f_ci is ion gyro-frequency), propagation angle approximately 90 degrees to the mean magnetic field, B_0, and compressibility shows a broad distribution, 0.1 < R > 0.9. On the other hand at f_sc>10f_ci, the propagation angle exhibits a broad range between 30-90 degree while R has a small variation: 0.2 < R > 0.5. We conjecture that at high frequencies, the perpendicularly propagating Alfven waves could partly explain the statistical analysis of spectra. To support our prediction of kinetic Alfven wave-dominated spectral slope behaviour at high frequency, we also present a theoretical model and simulate the magnetic field turbulence spectra due to the nonlinear evolution of kinetic Alfven waves. The present study also shows the analogy between the observational and simulated spectra.
We study the excitation function of the low-lying charmonium state: $Psi$(3686) in $bar p$ Au collisions taking into account their in-medium propagation. The time evolution of the spectral functions of the charmonium state is studied with a BUU type
transport model. We calculated the excitation function of $Psi$(3686) production and show that it is strongly effected by the medium. The energy regime will be available for the PANDA experiment.
The structure of the scalar mesons has been a subject of debate for many decades. In this work we look for $bar{q}q$ states among the physical resonances using an extended Linear Sigma Model that contains scalar, pseudoscalar, vector, and axial-vecto
r mesons both in the non-strange and strange sectors. We perform global fits of meson masses, decay widths and amplitudes in order to ascertain whether the scalar $bar{q}q$ states are below or above 1 GeV. We find the scalar states above 1 GeV to be preferred as $bar{q}q$ states.
We argue that with the current experimental setup of the OPERA neutrino experiment no `bit of information faster than light was or could be sent, and therefore no violation of Lorentz symmetry and/or causality was observed.
We investigate the influence of the asymmetric quark matter (rho_u e rho_d e rho_s) on the mass of the quasiparticles and the phase diagram of the chiral quark model parametrized at one-loop level of the renormalized theory, using the optimized pertu
rbation theory for the resummation of the perturbative series. The effect of various chemical potentials introduced in the grand canonical ensemble is investigated with the method of relativistic many-body theory. The temperature dependence of the topological susceptibility is estimated with the help of the Witten-Veneziano mass formula.
