Lepton flavor violating Z boson decays induced by scalar unparticle

We predict the branching ratios of the lepton flavor violating Z boson decays Z\to e^{\pm} \mu^{\pm}, Z\to e^{\pm} \tau^{\pm} and Z\to \mu^{\pm} \tau^{\pm} in the case that the lepton flavor violation is carried by the scalar unparticle mediation. We observe that their BRs are strongly sensitive to the unparticle scaling dimension and the branching ratios can reach to the values of the order of 10^{-8}, for the heavy lepton flavor case, for the small values of the scaling dimension.Comment: 15 pages, 5 figures, 1 tabl

Lepton Flavor Violating Z Decays in the Zee Model

We calculate lepton flavor violating (LFV) Z decays Z \to {{e_i^\pm}}e_j^\mp (i, j = e, \mu, \tau ; i\neq j) in the Zee model keeping in view the radiative leptonic decays e_i\to e_j\gamma (i = \mu, \tau ; j = e, \mu ; i\neq j), \mu decay and anomalous muon magnetic moment (\mu AMM). We investigate three different cases of Zee f_{ij} coupling (A) f_{e\mu}^2 = f_{\mu\tau}^2= f_{\tau e}^2, (B) f_{e\mu}^2 \gg f_{\tau e}^2 \gg f_{\mu\tau}^2, and (C) f_{\mu\tau}^2 \gg f_{e\mu}^2 \gg f_{\tau e}^2 subject to the neutrino phenomenology. Interestingly, we find that, although the case (C) satisfies the large excess value of \mu AMM, however, it is unable to explain the solar neutrino experimental result, whereas the case (B) satisfies the bi-maximal neutrino mixing scenario, but confronts with the result of \mu AMM experiment. We also find that among all the three cases, only the case (C) gives rise to largest contribution to the ratio B(Z\to e^\pm\tau^\mp)/B(Z\to \mu^\pm \mu^\mp) \simeq {10}^{-8} which is still two order less than the accessible value to be probed by the future linear colliders, whereas for the other two cases, this ratio is too low to be observed even in the near future for all possible LFV Z decay modes.Comment: 12 pages, RevTex, 2 figures, 3 Tables, typos corrected, reference added, version to appear in Phys. Rev.

A note on Friedmann equation of FRW universe in deformed Horava-Lifshitz gravity from entropic force

With entropic interpretation of gravity proposed by Verlinde, we obtain the Friedmann equation of the Friedmann-Robertson-Walker universe for the deformed Ho\v{r}ava-Lifshitz gravity. It is shown that, when the parameter of Ho\v{r}ava-Lifshitz gravity $\omega\rightarrow \infty$, the modified Friedmann equation will go back to the one in Einstein gravity. This results may imply that the entropic interpretation of gravity is effective for the deformed Ho\v{r}ava-Lifshitz gravity.Comment: 9 pages, no figure

Antimicrobial Activity of the Extract of Stem Bark of Diplotropis Ferruginea Benth

This is the first report about the antibacterial activity of Diplotropis ferruginea Benth. In this study, the ethanol extract of D. ferruginea was tested for its antimicrobial activity against strains gram-positive and gram-negative. In order to determine the minimal inhibitory concentration, assays were carried out by micro dilution method. The extract was screened for antimicrobial activity, and it showed antibacterial activity against Escherichia coli and Pseudomonas aeruginosa

Non-relativistic metrics with extremal limits

We present solutions of type IIB supergravity with z=2 Schrodinger asymptotics that admit an extremal limit, i.e. the black hole horizon has a double zero. These solutions are obtained as TsT transformations of the charged planar black hole in AdS_5 \times S^5. Unlike the uncharged solution, the Ramond-Ramond two-form is turned on. We study the thermodynamic properties of these new solutions, and we show that the ratio of shear viscosity to entropy density is 1/4\pi even in the extremal limit. We also consider the TsT-transformed soliton and show that, for a special radius of the compact circle, there is a confinement-deconfinement phase transition at zero temperature between the soliton and black hole phases.Comment: 23 pages, references and clarifications added, typos corrected, restriction in phase transition due to equation 6.5 emphasized; published versio

Particle Probe of Horava-Lifshitz Gravity

Kehagias-Sfetsos black hole in Ho\v{r}ava-Lifshitz gravity is probed through particle geodesics. Gravitational force of KS black hole becomes weaker than that of Schwarzschild around horizon and interior space. Particles can be always scattered or trapped in new closed orbits, unlike those falling forever in Schwarzschild black. The properties of null and timelike geodesics are classified with values of coupling constants. The precession rates of the orbits are evaluated. The time trajectories are also classified under different values of coupling constants for both null and timelike geodesics. Physical phenomena that may be observable are discussed.Comment: 10 pages, 8 figure

Observational constraints on Horava-Lifshitz cosmology

We use observational data from Type Ia Supernovae (SNIa), Baryon Acoustic Oscillations (BAO), and Cosmic Microwave Background (CMB), along with requirements of Big Bang Nucleosynthesis (BBN), to constrain the cosmological scenarios governed by Horava-Lifshitz gravity. We consider both the detailed and non-detailed balance versions of the gravitational sector, and we include the matter and radiation sectors. We conclude that the detailed-balance scenario cannot be ruled out from the observational point of view, however the corresponding likelihood contours impose tight constraints on the involved parameters. The scenario beyond detailed balance is compatible with observational data, and we present the corresponding stringent constraints and contour-plots of the parameters. Although this analysis indicates that Horava-Lifshitz cosmology can be compatible with observations, it does not enlighten the discussion about its possible conceptual and theoretical problems.Comment: 11 pages, 6 figures, version published in JCA

Lepton Flavour Violating Leptonic/Semileptonic Decays of Charged Leptons in the Minimal Supersymmetric Standard Model

We consider the leptonic and semileptonic (SL) lepton flavour violating (LFV) decays of the charged leptons in the minimal supersymmetric standard model (MSSM). The formalism for evaluation of branching fractions for the SL LFV charged-lepton decays with one or two pseudoscalar mesons, or one vector meson in the final state, is given. Previous amplitudes for the SL LFV charged-lepton decays in MSSM are improved, for instance the $\gamma$-penguin amplitude is corrected to assure the gauge invariance. The decays are studied not only in the model-independent formulation of the theory in the frame of MSSM, but also within the frame of the minimal supersymmetric SO(10) model within which the parameters of the MSSM are determined. The latter model gives predictions for the neutrino-Dirac Yukawa coupling matrix, once free parameters in the model are appropriately fixed to accommodate the recent neutrino oscillation data. Using this unambiguous neutrino-Dirac Yukawa couplings, we calculate the LFV leptonic and SL decay processes assuming the minimal supergravity scenario. A very detailed numerical analysis is done to constrain the MSSM parameters. Numerical results for SL LFV processes are given, for instance for tau -> e (mu) pi0, tau -> e (mu) eta, tau -> e (mu) eta', tau -> e (mu) rho0, tau -> e (mu) phi, tau -> e (mu) omega, etc.Comment: 36 pages, 3 tables, 5 .eps figure

Thermodynamics of Ho\v{r}ava-Lifshitz black holes

We study black holes in the Ho\v{r}ava-Lifshitz gravity with a parameter $\lambda$. For $1/3 \le \lambda < 3$, the black holes behave the Lifshitz black holes with dynamical exponent $0 3$, the black holes behave the Reissner-Nordstr\"om type black hole in asymptotically flat spacetimes. Hence, these all are quite different from the Schwarzschild-AdS black hole of Einstein gravity. The temperature, mass, entropy, and heat capacity are derived for investigating thermodynamic properties of these black holes.Comment: 12 pages, 5 figures, v2:substantial improved version to make connection to Lifshitz black holes and Reissner-Norstr\"om type black holes,v3: version to appear in EPJ