arXiv subjects

S. Jabeen

Publications and source records attributed to S. Jabeen.

3 recordsLinked to original sources

arXiv2025

Spectrum of five-times ionized krypton: Kr VI

This work describes the spectral analysis of five-times ionized krypton ion (Kr VI) using a high-resolution spectrogram recorded on a 3 m normal incidence vacuum spectrograph in the wavelength 230--2075~Å~region. For spectral excitation, a gas-puff triggered spark source was used. This work thoroughly examined all previously reported spectroscopic analyses for Kr VI. Many missing and new levels were added to the list of known energy levels with the help of several supportive transitions. The present experimental findings were theoretically supported within the pseudo-relativistic Hartree-Fock (HFR) formalism implemented in the Cowan suite of codes. A total of 52 (including eight new) energy levels were established with the help of 169 unique observed spectral lines (31 are new) assigned to 175 (6 doubly assigned) transitions. All observed and Ritz wavelengths were reported with their uncertainties, modeled intensities, and other evaluated radiative transition parameters such as transition probabilities and cancellation factors.

physics.atom-ph↗

arXiv2020

Critically Evaluated Energy Levels, Wavelengths, Transition Probabilities, and Intensities of Six-Times Ionized Cesium: Cs VII

Previously reported works on the spectrum of Cs VII are critically studied using supplementary spectrograms recorded on a 3 m normal incidence vacuum spectrograph in the wavelength region 300-1240 A at the Antigonish laboratory (Canada). We confirmed the results of the earlier work of Gayasov and Joshi on this spectrum. Our analysis is supported by extended calculations with the pseudo-relativistic Hartree-Fock (HFR) method with superposition of configuration interactions implemented in Cowan's suite of codes. In this critical evaluation, in addition to the accurate energy levels of Cs VII with their uncertainties, observed and Ritz wavelengths with uncertainties and transition probabilities, the uniformly-scaled intensities of Cs VII lines are also presented. A total of 196 lines attributed to 197 transitions enabled us to optimize the energy values of 72 levels in Cs VII spectrum. Furthermore, Ritz wavelengths of 141 possibly observable lines are provided along with their transition probabilities.

physics.atom-ph↗

arXiv2007

Search for Single Top Quark Production Using Likelihood Discriminants at D0 in Run II

We present an improved search for single top quarks in two production modes, s-channel (tb) and t-channel (tqb). The search is performed in the electron+jets and muon+jets decay channels, with one or more b-tagged jets, on nearly 370 pb^{-1} of D0 Run II data collected between August 2002 and October 2004. Impact-parameter based b-quark tagging is used to select signal-like events. We use a likelihood discriminant method to separate signals from backgrounds. The resulting expected/observed 95% confidence level upper limits on the single top quark production cross sections are 3.3/5.0pb (s-channel) and 4.3/4.4pb (t-channel).

hep-ex↗