Effective String Theory Inspired Potential and Meson Masses in Higher Dimension

Nambu-Goto action in classical bosonic string model for hadrons predicts quark-antiquark potential to be\cite{Nambu-Goto} $V(r)=-\frac{\gamma}{r}+\sigma r +\mu_0$. In this report we present studies of masses of heavy flavour mesons in higher dimension with our recently developed wave functions obtained following string inspired potential. We report the dimensional dependence of the masses of mesons. Our results suggest that as the meson mass increases with the number of extra spatial dimension, it will attain the Planck scale ($\sim 10^{19}GeV$) asymptotically at an astronomically large spatial dimension (we call it Planck dimension) $D_{Planck} \sim 10^{11}$, which sets the limit of applicability of Schrodinger equation in large dimension

Some Aspects of Incentive-Based Optimal Pricing and Environmental Regulation with Asymmetric Information.

The paper aims to analyze the problem of regulating a pollution-generating single product monopolistic firm in the presence of information asymmetry about the firm?s cost performance. Following Boyer and Laffont (1999), incentive-based optimal regulation of the firm?s price/ output and the environmental performance is characterized when costs are increasing in output and declining in pollution generated during production. Further, the regulatory agency/ legislator may or may not be politically motivated. When he/ she is politically inclined, the process of lobbying assumes that interest groups offer monetary contributions to the regulatory agency or the legislator. These contributions from the lobby help fund election campaigns. Thus, he/ she no longer behaves as a benevolent maximizer of social welfare, but instead maximizes a weighted average of social welfare and welfare of the lobby. Two alternative cases are considered: one, where the lobby represents environmental interests alone, and another, where the lobby stands solely for firm?s/ industry?s interests. The analysis derives interesting implications for incentive-based regulation of the firm. In general, pricing and environmental performance are distorted for the inefficient firm type under asymmetric information to restrict rents accruing to the efficient firm type. In the presence of the environmental lobby, the politically inclined regulator imposes more stringent environmental regulation under both full information and incomplete information as compared to the no-lobbying case. Interestingly, lobbying by the firm/ industry group also induces the politically motivated regulator to have more restrictive environmental regulation, albeit it now combines it with a higher regulated output for the inefficient firm type under incomplete information vis-…-vis the case of no-lobbying activity.

An analysis of the Isgur-Wise Function and its derivatives within a Heavy-Light QCD Quark Model

In determining the mesonic wave function from QCD inspired potential model, if the linear confinement term is taken as parent (with columbic term as perturbation), Airy's function appears in the resultant wave function - which is an infinite series. In the study of Isgur-Wise function (IWF) and its derivatives with such a wave function, the infinite upper limit of integration gives rise to divergence. In this paper, we have proposed some reasonable cut-off values for the upper limit of such integrations and studied the subsequent effect on the results. We also study the sensitivity of the order of polynomial approximation of the infinite Airy series in calculating the derivatives of IWF.Comment: 14 pages,6 tables 8 figure

Reionization constraints on primordial magnetic fields

We study the impact of the extra density fluctuations induced by primordial magnetic fields on the reionization history in the redshift range: $6 < z < 10$. We perform a comprehensive MCMC physical analysis allowing the variation of parameters related to primordial magnetic fields (strength, $B_0$, and power-spectrum index $n_{\scriptscriptstyle \rm B}$), reionization, and $\Lambda$CDM cosmological model. We find that magnetic field strengths in the range: $B_0 \simeq 0.05{-}0.3$ nG (for nearly scale-free power spectra) can significantly alter the reionization history in the above redshift range and can relieve the tension between the WMAP and quasar absorption spectra data. Our analysis puts upper-limits on the magnetic field strength $B_0 < 0.358, 0.120, 0.059$ nG (95 % c.l.) for $n_{\scriptscriptstyle \rm B} = -2.95, -2.9, -2.85$, respectively. These represent the strongest magnetic field constraints among those available from other cosmological observables.Comment: Accepted for publication in MNRAS; 9 pages, 6 figure