• S Panda

Articles written in Pramana – Journal of Physics

• Mass and decay constant of the (qq)-pion in a relativistic-potential model of independent quarks

Under the assumption that a meson is an assembly of independent quark and antiquark, confined in a first approximation by an effective potential$$V_q (r) = \raise.5ex\hbox{\scriptstyle 1}\kern-.1em/ \kern-.15em\lower.25ex\hbox{\scriptstyle 2} (1 + \gamma ^0 )(a^2 r + V_0 )$$ which presumably represents the non-perturbative gluon interactions, the mass and decay constant of the (qq)-pion together with the masses of ρ and ω-mesons are calculated by considering perturbatively the corrections due to the possible residual interaction such as quark-pion coupling arising out of the requirement of chiral symmetry and quark-gluon coupling arising out of one-gluon exchange and that due to the spurious motion of center of mass of the meson core.This results in the physical mass of the (qq)-pion in consistency with that of the PCAC-pion and the pion decay constant in a reasonable agreement with experiment.

• Black holes in brane worlds

A Kerr metric describing a rotating black hole is obtained on the three brane in a five-dimensional Randall-Sundrum brane world by considering a rotating five-dimensional black string in the bulk. We examine the causal structure of this space-time through the geodesic equations.

• Chemical potential and internal energy of the noninteracting Fermi gas in fractional-dimensional space

Chemical potential and internal energy of a noninteracting Fermi gas at low temperature are evaluated using the Sommerfeld method in the fractional-dimensional space. When temperature increases, the chemical potential decreases below the Fermi energy for any dimension equal to 2 and above due to the small entropy, while it increases above the Fermi energy for dimensions below 2 as a result of high entropy. The ranges of validity of the truncated series expansions of these quantities are extended from low to intermediate temperature regime as well as from high to relatively low density regime by using the Pad ́e approximant technique.

• Effect of conduction band nonparabolicity on the optical properties in a single quantum well under hydrostatic pressure and electric ﬁeld

The effect of conduction band nonparabolicity on the linear and nonlinear optical properties such as absorption coefﬁcients, and changes in the refractive index are calculated in the Al0.3Ga0.7As/GaAs heterostructure-based symmetric rectangular quantum well under applied hydrostatic pressure and electric ﬁeld. The electron envelope functions and energies are calculated in the effective mass equation including the conduction band nonparabolicity. The linear and nonlinear optical properties have been calculated in the density matrix formalism with two-level approximation. The conduction band nonparabolicity shifts the positions of the optical properties and decreases their strength compared to those without this correction. Both the optical properties are enhanced with the applied hydrostatic pressure. While the absorption coefﬁcients are bleached under the combined effect of high pressure and electric ﬁeld, the bleaching effect is reduced when nonparabolicity is included.

• Pramana – Journal of Physics

Volume 96, 2022
All articles
Continuous Article Publishing mode

• Editorial Note on Continuous Article Publication

Posted on July 25, 2019