• N A Narasimham

Articles written in Pramana – Journal of Physics

• Intensity ratios of mesonic x-ray lines$$K_{\alpha _1 } , K_{\alpha _2 }$$ and$$L_{\alpha _1 } , L_{\beta _2 }$$

Intensity ratios ofμ-mesonic x-rays in some heavy elements are discussed. Intensity ratios of the$$K_{\alpha _1 } /K_{\alpha _2 }$$ and$$L_{\alpha _1 } /L_{\beta _2 }$$ lines have been calculated for206Pb,209Bi and238U with relativistic wavefunctions and retardation effect. Though for a refined calculation, it is necessary to take into consideration several features that are peculiar to mesonic atoms, the present calculations have shown that the observed intensity ratios of mesonic x-rays are not anomalous.

• On the widths ofK levels of heavy elements

The ratios of the widths ofK levels of heavy elements with atomic number 70 to 92 have been calculated with relativistic wave functions, retardation, screening and field theoretical corrections to relativistic energy. The calculated values have been compared with the available observed data and good agreement has been obtained.

• Reinvestigation of the second negative (A2ΠuX2Πg) band system of O2+

TheA2Πustate of O2+ was earlier established as an inverted state contrary to previous assumptions. The rotational analysis of a few more bands of theA-X system of O2+ has now been completed. These studies show that the spin-orbit coupling constantA in theA2Πustate gradually varies with the vibrational quantum numberν and is found to be positive forν⩾6. It has also been observed that the spia-rotation interaction is not negligible in theA2Πustate. The spin splitting constantγ is reported for various vibrational levels of this electronic state.

• Rotational analysis of the 0–9, 0–10 and 0–11 bands of theA2IIu-X2IIg band system of (16O18O)+

High-resolution spectra of the 0–9, 0–10 and 0–11 bands of theA2IIuX2IIg system of (16O18O)+ ion have been studied for their rotational structure. This study enables a direct determination of the Λ-doubling parameters of theA2IIu andX2IIg states. The model of ‘pure precession’ explains, though not entirely, the Λ-doubling of theX2IIa state as arising out of its interaction with theB2Σg state. The Λ-doubling in theA2IIu state was found insignificant.

• Rotational analysis of the ultraviolet bands of PS

The 2-0, 1-0 and 0-0 bands of the ultraviolet system of PS have been analysed for their rotational structure. It is shown that they involve the transitionC2Σ -X2 Πr(a). TheC2Σ state shows a significant spin doubling.

• # Pramana – Journal of Physics

Current Issue
Volume 93 | Issue 6
December 2019

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019