Bounds on charged higgs boson in the 2HDM type III from Tevatron

We consider the Two Higgs Doublet Model (2HDM) of type III which leads to Flavour Changing Neutral Currents (FCNC) at tree level. In the framework of this model we can use an appropriate form of the Yukawa Lagrangian that makes the type II model limit of the general type III couplings apparent. This way is useful in order to compare with the experimental data which is model dependent. The analytical expressions of the partial width $\Gamma (t \to H^+ b)$ are derived and we compare with the data available at this energy range. We examine the limits on the new parameters $\lambda_{ij}$ from the validness of perturbation theory.Comment: 14 pages, 4 figures, Universidad Nacional de Colombia. typos correcte

CP Nonconservation in e+e−→ttˉge^+e^-\to t\bar tg

CP violation effects in $e^+ e^- \to t\bar tg$ are examined. CP-odd, $T_n$-odd and $T_n$-even observables can both be used to extract information on the real and imaginary parts of Feynman amplitudes. Two Higgs doublet model with CP violating phase from neutral Higgs exchange is used to estimate possible effects.Comment: 9 pages, 4 Figures, Late

CP Violation in Top Physics at the NLC

Top quark is extremely sensitive to non-standard CP violating phases. General strategies for exposing different types of phases at the NLC are outlined. SUSY phase(s) cause PRA in $t\to Wb$. The transverse polarization of the $\tau$ in the reaction $t\to b\tau\nu$ is extremely sensitive to a phase from the charged Higgs sector. Phase(s) from the neutral Higgs sector cause appreciable dipole moment effects and lead to sizable asymmetries in $e^+e^-\to t\bar tH^0$ and $e^+e^-\to t\bar t\nu_e\bar\nu_e$.}]Comment: 4 pages, Latex, 2 figures. For the Proceedings of the 28th Int. Conf. on HEP, Warsaw(July 1996

Getting beta-alpha without penguins

Oscillation effects in B0 -> Ks D0 and related processes are considered to determine delta=beta-alpha+pi. We suggest that D0 decays to CP eigenstates used in concert with inclusive D0 decays provide a powerful method for determining delta cleanly i.e. without any complication from penguin processes. The CP asymmetry is expected to be <=40% for D0 decays to non-CP eigenstates and <=80% for decays to CP eigenstates. This method can lead to a fairly accurate determination of delta with O(10^8-10^9) B-mesons.Comment: 4 pages 1 figure; Version 2: minor changes; references added; Some changes in response to Referee Comment

Desperately Seeking Non-Standard Phases via Direct CP Violation in b→sg∗b\to sg^\ast Process

Attributing the recent CLEO discovery of $B \to \eta' + X_s$ to originate (primarily) from the fragmentation of an off-shell gluon ($g^*$) via $b \to s + g^*$, $g^* \to g + \eta'$, we emphasize that many such states ($X_g$) should materialize. Indeed the hadronic fragments ($X_g$) of $g^*$ states are closely related to those seen in $\psi \to \gamma (\phi, \omega) + X_g$. A particular final state of considerable interest is $X_g=K^+K^-$. Signals from such states in $B$ decays can be combined to provide a very sensitive search for CP violating phase(s) from non-standard physics. The method should work even if the contribution of these source(s) to the rates is rather small ($\sim10$) to the point that a comparison between theory and experiment may find it extremely difficult to reveal the presence of such a new physics.Comment: 16 pages, 5 figure

Pure Leptonic Radiative Decays B±,Ds→ℓνγB^\pm, D_s\to\ell\nu\gamma and the Annihilation Graph

Pure leptonic radiative decays of heavy-light mesons are calculated using a very simple non-relativistic model. Dominant contribution originates from photon emission from light initial quark. We find $BR(B^\pm\to\ell\nu\gamma)\sim3.5\times10^{-6}$ and $BR(D_s\to \ell\nu\gamma)\sim1.7 \times10^{-4}$. The importance of these reactions to clarify the dynamics of the annihilation graph is emphasized.Comment: 7 pages, LaTeX, 3 figure

The Anomalous Magnetic Moment of the Muon and Higgs-Mediated Flavor Changing Neutral Currents

In the two-Higgs doublet extension of the standard model, flavor-changing neutral couplings arise naturally. In the lepton sector, the largest such coupling is expected to be $\mu-\tau-\phi#. We consider the effects of this coupling on the anomalous magnetic moment of the muon. The resulting bound on the coupling, unlike previous bounds, is independent of the value of other unknown couplings. It will be significantly improved by the upcoming E821 experiment at Brookhaven National Lab.Comment: 7 pages Latex, 2 figure