Probing New Physics From CP Violation in Radiative B Decays

When new CP-violating interactions are dominated by flavor changing neutral particle exchanges, that may occur in many extensions of the standard model. We examine a type 3 two Higgs doublet model and find that direct CP asymmetries can be as large as about 25% . Time-dependent and time-integrated mixing-induced CP asymmetries up to 85 and 40 %, respectively, are possible without conflict with other constraints. It mainly requirs an enhanced chromo-magnetic dipole $b\to sg$ decay to be close to the present experimental bound.Comment: 7 pages, latex, no figure

Beyond the Standard Model in B Decays: Three Topics

Three new results are discussed: (a) A non-vanishing amplitude for the `wrong sign{'} kaon decay $B \to J/\Psi \bar{K}$ or its CP conjugate is shown to be a necessary condition for obtaining different CP asymmetries in $B \to J/\Psi K_{S,L}$. A significant effect would require a scale of new physics far below the weak scale, all but ruling out this possibility. (b) The leading isospin breaking contributions to the $B \to K^* \gamma$ decay amplitudes can be calculated in QCD factorization, providing a sensitive probe of the penguin sector of the effective weak Hamiltonian. New physics models which reverse the predicted $10-20$ Standard Model amplitude hierarchy could be ruled out with more precise data. (c) A slowly falling $g^* g \eta^\prime$ form factor can be ruled out using the $\eta^\prime$ spectrum obtained by ARGUS at the $\Upsilon (1S)$. The decay $b \to s g \eta^\prime$ is therefore highly suppressed and the origin of the anomalously large $B \to \eta^\prime X_s$ rate remains unknown, perhaps requiring the intervention of New Physics.Comment: 12 pages, 3 figure

Formation of a condensed state with macroscopic number of phonons in ultracold Bose gases

A mechanism for the formation of a new type of stationary state with macroscopical number of phonons in condensed atomic gases is proposed. This mechanism is based on generating longitudinal phonons as a result of parametric resonance caused by a permanent modulation of the transverse trap frequency in an elongated trap. The phonon-phonon interaction predetermines the self-consistent evolution which is completed with macroscopic population of one from all levels within the energy interval of parametric amplification. This level proves to be shifted to the edge of this interval. All other levels end the evolution with zero population.Comment: 9 pages, 8 figure

Family nonuniversal Z-prime and b to s Gamma decay

We have calculated the branching ratio and CP asymmetry of B-->X_s +gamma decay within the family--nonuniversal Z' models. We have established certain bounds on the model parameters using the present experimental bounds. We also comment on the role of family--nonuniversality in the hadronic decay modes of the B meson.Comment: 15 pages, 2 figure

The top squark-mediated annihilation scenario and direct detection of dark matter in compressed supersymmetry

Top squark-mediated annihilation of bino-like neutralinos to top-antitop pairs can play the dominant role in obtaining a thermal relic dark matter abundance in agreement with observations. In a previous paper, it was argued that this can occur naturally in models of compressed supersymmetry, which feature a running gluino mass parameter that is substantially smaller than the wino mass parameter at the scale of apparent gauge coupling unification. Here I study in some more detail the parameter space in which this is viable, and compare to other scenarios for obtaining the observed dark matter density. I then study the possibility of detecting the dark matter directly in future experiments. The prospects are consistently very promising for a wide variety of model parameters within this scenario.Comment: 17 pages. v2: additions to figures 4 and

Manifestation of superfluidity in an evolving Bose-condensed gas

We study the generation of excitations due to an ''impurity''(static perturbation) placed into an oscillating Bose-condensed gas in the time-dependent trapping field. It is shown that there are two regions for the position of the local perturbation. In the first region the condensate flows around the ''impurity'' without generation of excitations demonstrating superfluid properties. In the second region the creation of excitations occurs, at least within a limited time interval, revealing destruction of superfluidity. The phenomenon can be studied by measuring the damping of condensate oscillations at different positions of the ''impurity''

Testing for new physics in singly Cabibbo suppressed D decays

We devise tests for a new physics origin of the recently measured direct CP violation in singly Cabibbo suppressed D decays. The tests take the form of sum rules for the CP asymmetries in various D decays. They are based on the fact that within the standard model CP violation arises from interference of the dominant tree amplitudes with the Delta I=1/2 penguin amplitudes. The sum rules would be violated if the observed CP violation is due to new physics contributions to the effective weak Hamiltonian that change isospin by Delta I=3/2.Comment: 6 page