Production of Ξ−\Xi^--hypernuclei via the (K−,K+K^-,K^+) reaction in a quark-meson coupling model

We study the production of $\Xi^-$-hypernuclei, $^{12}_{\Xi^{-}}$Be and $^{28}_{\Xi^{-}}$Mg, via the ($K^-,K^+$) reaction within a covariant effective Lagrangian model, employing the bound $\Xi^-$ and proton spinors calculated by the latest quark-meson coupling model. The present treatment yields the $0^\circ$ differential cross sections for the formation of simple s-state $\Xi^-$ particle-hole states peak at a beam momentum around 1.0 GeV/c with a value in excess of 1 $\mu$b.Comment: Accepted version with miner changes, 4 pages, 2 figures, Presented at the 20th International IUPAP Conference on Few-Body Problems in Physics, 20 - 25 August, 2012, Fukuoka, Japa

Photoproduction of hypernuclei within the quark-meson coupling model

We study the photoproduction of the ^12{_Lambda}B hypernucleus within a fully covariant effective Lagrangian based model, employing Lambda bound state spinors derived from the latest quark-meson coupling model. The kaon production vertex is described via creation, propagation and decay of N*(1650), N*(1710), and N*(1720) intermediate baryonic resonant states in the initial collision of the photon with a target proton in the incident channel. The parameters of the resonance vertices are fixed by describing the total and differential cross section data on the elementary gamma (p, K+) Lambda reaction in the energy regime relevant to the hypernuclear production. It is found that the hypernuclear production cross sections calculated with the quark model based hyperon bound state spinors differ significantly from those obtained with the phenomenological Dirac single particle wave functions.Comment: 16 pages, 5 figures, version to appear in Phys. Lett.

Studying the Imaging Characteristics of Ultra Violet Imaging Telescope (UVIT) through Numerical Simulations

Ultra-Violet Imaging Telescope (UVIT) is one of the five payloads aboard the Indian Space Research Organization (ISRO)'s ASTROSAT space mission. The science objectives of UVIT are broad, extending from individual hot stars, star-forming regions to active galactic nuclei. Imaging performance of UVIT would depend on several factors in addition to the optics, e.g. resolution of the detectors, Satellite Drift and Jitter, image frame acquisition rate, sky background, source intensity etc. The use of intensified CMOS-imager based photon counting detectors in UVIT put their own complexity over reconstruction of the images. All these factors could lead to several systematic effects in the reconstructed images. A study has been done through numerical simulations with artificial point sources and archival image of a galaxy from GALEX data archive, to explore the effects of all the above mentioned parameters on the reconstructed images. In particular the issues of angular resolution, photometric accuracy and photometric-nonlinearity associated with the intensified CMOS-imager based photon counting detectors have been investigated. The photon events in image frames are detected by three different centroid algorithms with some energy thresholds. Our results show that in presence of bright sources, reconstructed images from UVIT would suffer from photometric distortion in a complex way and the presence of overlapping photon events could lead to complex patterns near the bright sources. Further the angular resolution, photometric accuracy and distortion would depend on the values of various thresholds chosen to detect photon events.Comment: Submitted to PASP, 16 Pages, 9 figure

A Foucauldian Theory of American Islamophobia

With the emergence of ISIS andAmerican public furor over allowing Syrian refugees safe haven, Muslim Americans find themselves once again in the cross-hairs of a nation obsessed with searching for answers and someone to blame. I argue that the premise behind American anti-Muslim sentiment is rooted in two of Michel Foucault’s concepts -“biopower” and “pastoral power.” This article is divided in two halves. In the first, I argue that American nationalism is articulated in a unique way, particularly through “pastoral power.” In conjunction with an “imagined” American nationhood (Anderson 1983), it has created a state that is often viewed as secular, but is quite Christian ideologically and structurally. Drawing on Göle (1996), I surmise that the Western “culture of confession,” an extension of pastoral power, is incompatible with Islam – or at least is viewed as such. In the second half, I present my main argument towards a new understanding of Foucault’s (1990) biopower in the context of the sovereign and its ability to designate who is “sacred,” a la Agamben (1998). I suggest that a new evaluation of Agamben (1998) should be undertaken to account for the renewed racialization of and discrimination towards American Muslims