arXiv subjects

F. Shaker

Publications and source records attributed to F. Shaker.

3 recordsLinked to original sources

arXiv2021

Optical calibration of the SNO+ detector in the water phase with deployed sources

SNO+ is a large-scale liquid scintillator experiment with the primary goal of searching for neutrinoless double beta decay, and is located approximately 2 km underground in SNOLAB, Sudbury, Canada. The detector acquired data for two years as a pure water Cherenkov detector, starting in May 2017. During this period, the optical properties of the detector were measured in situ using a deployed light diffusing sphere, with the goal of improving the detector model and the energy response systematic uncertainties. The measured parameters included the water attenuation coefficients, effective attenuation coefficients for the acrylic vessel, and the angular response of the photomultiplier tubes and their surrounding light concentrators, all across different wavelengths. The calibrated detector model was validated using a deployed tagged gamma source, which showed a 0.6% variation in energy scale across the primary target volume.

physics.ins-det↗

arXiv2016

Analytical study of properties of holographic superconductors with exponential nonlinear electrodynamics

Based on the Sturm-Liouville (SL) eigenvalue problem, we analytically study several properties of holographic $s$-wave superconductors with exponential nonlinear electrodynamics in the background of Schwarzschild anti-de Sitter (AdS) black holes. We assume the probe limit in which the scalar and gauge fields do not back react on the background metric. We show that for this system, one can still obtain an analytical relation between the critical temperature and the charge density. Interestingly enough, we find that logarithmic nonlinear electrodynamics decreases the critical temperature, $T_c$, of the holographic superconductors compared to the linear Maxwell field. This implies that the nonlinear electrodynamics make the condensation harder. The analytical results obtained in this paper are in good agreement with the existing numerical results. We also compute the critical exponent near the critical temperature and find out that it is still $1/2$ which seems to be an universal value in mean field theory.

hep-th↗

arXiv2016

Analytical study of holographic superconductor in Born-Infeld electrodynamics with backreaction

We generalize the analytical investigation on the properties of $s$-wave holographic superconductors in the presence of Born-Infeld nonlinear electrodynamics by taking the backreaction into account. We find that in the presence of nonlinear gauge field, one can still employ the analytical method when the backreaction is turned on. Our calculation is based on the Sturm-Liouville eigenvalue problem, which is a variational method. For the system under consideration, we obtain the relation between the critical temperature and the charge density. We find that both backreaction and Born-Infeld parameters decrease the critical temperature of the superconductor and make the condensation harder. At the ned of paper, we calculate the critical exponent associated with the condensation near the critical temperature and find that it has the universal value $1/2$ of the mean field theory.

hep-th↗