A Separate Higgs?

We investigate the possibility of a multi-Higgs doublet model where the lightest neutral Higgs boson ($h^0$) decouples from the fermion sector. We are partially motivated by the four $\ell^+\ell^-\gamma\gamma$ events with $M_{\gamma\gamma}\simeq60$\,GeV recently observed by the L3 collaboration, which could be a signal for $Z\to (Z^*\to \ell^+\ell^-)+(h^0\to \gamma\gamma)$. Collider signatures for the additional physical Higgs bosons present in such models are discussed.Comment: 8 pages (plus 2 figures, available by request), latex, ANL-HEP-PR-92-10

Prospects for Direct CP Violaton in Exclusive and Inclusive Charmless B decays

Within the Standard Model, CP rate asymmetries for $B\to K^-\pi^{+,0}$ could reach 10%. With strong final state phases, they could go up to 20--30%, even for $\bar K^0\pi^-$ mode which would have opposite sign. We can account for $K^-\pi^{+}$, $\bar K^0\pi^-$ and $\phi K$ rate data with new physics enhanced color dipole coupling and destructive interference. Asymmetries could reach 40--60% for $K\pi$ and $\phi K$ modes and are all of the same sign. We are unable to account for $K^-\pi^0$ rate. Our inclusive study supports our exclusive results.Comment: Minor changes, correct a small bug in Fig. 1(b). Version to appear in Phys. Rev. Let

Spin Effects in the Local Density of States of GaAs

We present spin-resolved measurements of the local density of states in Si doped GaAs. Both spin components exhibit strong mesoscopic fluctuations. In the magnetic quantum limit, the main features of the spin-up and spin-down components of the local density of states are found to be identical apart from Zeeman splitting. Based on this observation, we introduce a mesoscopic method to measure the $g$-factor in a material where macroscopic methods are severely restricted by disorder. Differences between the spin-up and spin-down components are discussed in terms of spin relaxation due to spin-orbit coupling.Comment: 4 pages and 5 figure

CP Violation in a Multi-Higgs Doublet Model

We study CP violation in a multi-Higgs doublet model based on a $S_3 \times Z_3$ horizontal symmetry. We consider two mechanisms for CP violation in this model: a) CP violation due to complex Yukawa couplings; and b) CP violation due to scalar-pseudoscalar mixings. We find that the predictions for $\epsilon'/\epsilon$, CP violation in B decays and the electric dipole moments of neutron and electron are different between these two mechanisms. These predictions are also dramatically different from the minimal Standard Model predictions.Comment: 17 pages + one figure, Revtex. Talk presented by Deshpande at the Conference WHEPP-3, December 199

Model-independent analysis of \bbox{B}-\bbox{\bar B} mixing and \bbox{CP} violation in \bbox{B} decays

We present a framework to analyze effects of new physics beyond the standard model on $B$-$\bar B$ mixing and $CP$ violation in $B$ decays in a model-independent manner. Assuming that tree level decay amplitudes are dominated by the standard model ones, new physics contribution to the $B$-$\bar B$ mixing can be extracted from several measurements at $B$ factories. Using this framework, we show the present constraint on new physics contribution to the $B$-$\bar B$ mixing, and illustrate constraints expected to be given by future experiments at $B$ factories. We also point out a possibility that $CP$ asymmetries in $B\rightarrow\psi K_S$, $B\rightarrow\pi\pi$, and $B\rightarrow DK$ modes look consistent with the standard model, even if a large new physics contribution is present in the $B$-$\bar B$ mixing.Comment: 11 pages, 3 Postscript figures, also available via anonymous ftp at ftp://ftp.kek.jp/kek/preprints/TH/TH-44

Left-Right Symmetry and Supersymmetric Unification

The existence of an SU(3) X SU(2)_L X SU(2)_R X U(1) gauge symmetry with g_L = g_R at the TeV energy scale is shown to be consistent with supersymmetric SO(10) grand unification at around 1O^{16} GeV if certain new particles are assumed. The additional imposition of a discrete Z_2 symmetry leads to a generalized definition of R parity as well as highly suppressed Majorana neutrino masses. Another model based on SO(10) X SO(10) is also discussed.Comment: 11 pages, 2 figures not included, UCRHEP-T124, Apr 199

Propagating residual biases in masked cosmic shear power spectra

In this paper we derive a full expression for the propagation of weak lensing shape measurement biases into cosmic shear power spectra including the effect of missing data. We show using simulations that terms higher than first order in bias parameters can be ignored and the impact of biases can be captured by terms dependent only on the mean of the multiplicative bias field. We identify that the B-mode power contains information on the multiplicative bias. We find that without priors on the residual multiplicative bias $\delta m$ and stochastic ellipticity variance $\sigma_e$ that constraints on the amplitude of the cosmic shear power spectrum are completely degenerate, and that when applying priors the constrained amplitude $A$ is slightly biased low via a classic marginalisation paradox. Using all-sky Gaussian random field simulations we find that the combination of $(1+2\delta m)A$ is unbiased for a joint EE and BB power spectrum likelihood if the error and mean (precision and accuracy) of the stochastic ellipticity variance is known to better than $\sigma(\sigma_e)\leq 0.05$ and $\Delta\sigma_e\leq 0.01$, or the multiplicative bias is known to better than $\sigma(m)\leq 0.07$ and $\Delta m\leq 0.01$.Comment: 12 pages, accepted to the Open Journal of Astrophysics, comments welcom

CP-Violation For B→Xsl+l−B \to X_sl^+l^- Including Long-Distance Effects

We consider the CP violating effect for $B\to X_sl^+l^-$ process, including both short and long distance effects. We obtain the CP asymmetry parameter and present its variation over the dilepton mass.Comment: 9 pages, Latex file, one figure include

Tiny scale opacity fluctuations from VLBA, MERLIN and VLA observations of HI absorption toward 3C 138

The structure function of opacity fluctuations is a useful statistical tool to study tiny scale structures of neutral hydrogen. Here we present high resolution observation of HI absorption towards 3C 138, and estimate the structure function of opacity fluctuations from the combined VLA, MERLIN and VLBA data. The angular scales probed in this work are ~ 10-200 milliarcsec (about 5-100 AU). The structure function in this range is found to be well represented by a power law S_tau(x) ~ x^{beta} with index beta ~ 0.33 +/- 0.07 corresponding to a power spectrum P_tau(U) ~ U^{-2.33}. This is slightly shallower than the earlier reported power law index of ~ 2.5-3.0 at ~ 1000 AU to few pc scales. The amplitude of the derived structure function is a factor of ~ 20-60 times higher than the extrapolated amplitude from observation of Cas A at larger scales. On the other hand, extrapolating the AU scale structure function for 3C 138 predicts the observed structure function for Cas A at the pc scale correctly. These results clearly establish that the atomic gas has significantly more structures in AU scales than expected from earlier pc scale observations. Some plausible reasons are identified and discussed here to explain these results. The observational evidence of a shallower slope and the presence of rich small scale structures may have implications for the current understanding of the interstellar turbulence.Comment: 6 pages, 5 figures. Accepted for publication in ApJ. The definitive version will be available at http://iopscience.iop.org