W-pair production in Unparticle Physics

We consider the $W$-pair production for both $e^+e^-$ and hadron colliders in the context of unparticle physics associated with the scale invariant sector proposed by Georgi. We have shown that the unparticle contributions are quite comparable with standard model (SM) specially for low values of non-integral scaling dimension $(d_{\cal U})$ and hence it is worthwhile to explore in future colliders.Comment: 11 pages, 9 figures, 2 tables, included a new vertex in eqn(1) which was overlooked. Accordingly we updated figures 1,2,3,5,7,9 and modified the tables (1 & 2). Additional references adde

Non-extensive Statistical Mechanics and Black Hole Entropy From Quantum Geometry

Using non-extensive statistical mechanics, the Bekenstein-Hawking area law is obtained from microstates of black holes in loop quantum gravity, for arbitrary real positive values of the Barbero-Immirzi parameter$(\gamma)$. The arbitrariness of $\gamma$ is encoded in the strength of the "bias" created in the horizon microstates through the coupling with the quantum geometric fields exterior to the horizon. An experimental determination of $\gamma$ will fix this coupling, leaving out the macroscopic area of the black hole to be the only free quantity of the theory.Comment: 6 pages, published versio

Thermodynamics of Sultana-Dyer Black Hole

The thermodynamical entities on the dynamical horizon are not naturally defined like the usual static cases. Here I find the temperature, Smarr formula and the first law of thermodynamics for the Sultana-Dyer metric which is related to the Schwarzschild spacetime by a time dependent conformal factor. To find the temperature ($T$), the chiral anomaly expressions for the two dimensional spacetime are used. This shows an application of the anomaly method to study Hawking effect for a dynamical situation. Moreover, the analysis singles out one expression for temperature among two existing expressions in the literature. Interestingly, the present form satisfies the first law of thermodynamics. Also, it relates the Misner-Sharp energy ($\bar{E}$) and the horizon entropy ($\bar{S}$) by an algebraic expression $\bar{E}=2\bar{S}T$ which is the general form of the Smarr formula. This fact is similar to the usual static black hole cases in Einstein's gravity where the energy is identified as the Komar conserved quantity.Comment: typos corrected, to appear in JCA