Effects of an intermediate scale in SUSY grand unification

We discuss the production of lepton flavor violation and EDMs and the viability of the $b-\tau$ unification hypothesis in SUSY grand unification with an intermediate gauge symmetry breaking scale.Comment: 3 pages (Latex, esprc2.sty used), talk given at 4th International Conference on Supersymmetry (SUSY '96, College Park, MD, May 29 - June 1, 1996

Limits on Low Scale Gravity from e+e−→W+W−,ZZe^+ e^- \to W^+ W^-, ZZ and γγ\gamma \gamma

It has been proposed recently that the scale of quantum gravity (``the string scale'') can be $M_S \sim$ few TeV with $n \geq 2$ extra dimensions of size $R \stackrel{<}{\sim}$ mm so that, at distances greater than $R$, Newtonian gravity with $M_{Pl} \sim 10^{18}$ GeV is reproduced if $M_{Pl}^2 \sim R^n M_S^{n+2}$. Exchange of virtual gravitons in this theory generates higher-dimensional operators involving SM fields, suppressed by powers of $M_S$. We discuss constraints on this scenario from the contribution of these operators to the processes $e^+ e^- \to W^+ W^-, ZZ, \gamma \gamma$. We find that LEP2 can place a limit $M_S \approx 1$ TeV from $e^+ e^- \to W^+ W^-, ZZ, \gamma \gamma$.Comment: Replacing an earlier version. A discussion of using polarized electron beams and some minor comments have been adde

Exact calculations of vertex sˉγb\bar{s}\gamma b and sˉZb\bar{s} Z b in the unitary gauge

In this paper, we present the exact calculations for the vertex $\bar{s}\gamma b$ and $\bar{s} Z b$ in the unitary gauge. We found that (a) the divergent- and $\mu$-dependent terms are left in the effective vertex function $\Gamma^\gamma_\mu(p,k)$ for $b \to s \gamma$ transition even after we sum up the contributions from four related Feynman diagrams; (b) for an on-shell photon, such terms do not contribute et al; (c) for off-shell photon, these terms will be canceled when the contributions from both vertex $\bar{s}\gamma b$ and $\bar{s} Z b$ are taken into account simultaneously, and therefore the finite and gauge independent function $Z_0(x_t)=C_0(x_t)+ D_0(x_t)/4$, which governs the semi-leptonic decay $b \to s l^- l^+$, is derived in the unitary gauge.Comment: 13 pages, 2 figures, Revte

Electric dipole moments and b-τ\tau unification in the presence of an intermediate scale in SUSY grand unification

We show that an intermediate gauge symmetry breaking scale can be a significant source of electric dipole moments for the electron and neutron in supersymmetric grand unified theories. New phases, similar to that of the CKM matrix, appear which do not arise from the supersymmetry (SUSY) breaking operators. To illustrate, we choose some grand unified SUSY models having an intermediate gauge symmetry breaking scale with some attractive features. We also show how well the $b-\tau$ unification hypothesis works in this class of models.Comment: 14 pages(Latex), 2 PS Figures (uuencoded, epsf.tex

CP Violating Rate Difference Relations for B→PPB\to PP and B→PVB \to PV in Broken SU(3)

Within the standard model there exist certain relations between CP violating rate differences in B decays in the SU(3) limit. We study SU(3) breaking corrections to these relations in the case of charmless, hadronic, two body $B$ decays using the improved factorization model of Ref.\cite{3}. We consider the cases $B \to PP$ and $B \to PV$ for both $B_d$ and $B_s$ mesons. We present an estimate for $A_{CP}(\pi^- \pi^+)$ in terms of $A_{CP}(K^- \pi^+)$.Comment: Latex 13 pages, no figure

Branching Ratios and CP Asymmetries of B Decays to a Vector and a Pseudoscalar Meson

We consider two body decays of B meson into a light vector (V) and a pseudoscalar (P) meson. The constraint obtained from the $B\to P P$ modes on the parameter space of the input parameters is imposed also on $B\to V P$ modes. In particular we constrain $\xi\equiv (1/N_c)$ for those modes from recently measured $B\to \omega K, \phi K$ and are able to get a satisfactory pictures for all modes where data exists. Modes that should be seen shortly and those with possibly large CP asymmetries are identified.Comment: 15 pages(Latex), 3 Figure

Determining the Weak Phase γ\gamma in the Presence of Rescattering

We suggest a new technique to determine the CKM phase $\gamma$ {\em without} neglecting the (soft) final state rescattering effects. We use (time integrated) $B$ meson decay rates to $\pi$'s and $K$'s. A set of 5 $\Delta S = 0$ (or 1 $\Delta S =0$ and 4 $\Delta S= 1$) decay rates is used to compute the strong phases and magnitudes of the tree level and penguin contributions as functions of $\gamma$. These are used to {\em predict} a $\Delta S = 1$ $(\Delta S = 0) B_{d/s}$ decay rate as a function of $\gamma$ (using SU(3) symmetry). The measurement of this decay rate then gives $\gamma$. We illustrate this technique using different cases. Most of the decay modes we use are expected to be accessible at the B-factories (e^+ e^- or hadron machines).Comment: LaTeX file, 15 pages including 2 figures. Replacing an earlier version. In version 4, we have corrected some typographic errors. We have also clarified which decay modes require external tagging and have changed/added some comment

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

Influence of the Calcination Temperature on the Combustion Synthesized Perovskite LaMnO3 Compound

A simple combustion method based on principles of propellent chemistry in which Polyvinyl alcohol (PVA) as fuel and nitrates as oxidizer were used for synthesizing the perovskite like LaMnO3 powders. The oxidizer to fuel ratio was maintained at 5 : 1. The darkish black powder obtained was calcined at 800 °C and 1000 °C for 5 hour. The combustion and thermal decomposition of the precursor were investigated using the TG-DTA and Fourier Transform Infra-Red (FT-IR) techniques. The X-ray diffraction (XRD) pattern of all three samples i.e., un-heated LaMnO3 powder (LMO-UH), calcined at 800 °C (LMO-800) and at 1000 °C (LMO-1000) were carried out. The single phase orthorhombic crystal structure was revealed to crystallize at LMO-800 and LMO-1000 with elevation in the crystalline size. A small impurity peak at 28.7° was seen of Mn3O4 for LMO-UH, which vanished after calcining it. The strong absorption in FT-IR spectra found at around 615 cm – 1 was due to the formation of metal-oxygen (M-O) bond. Moreover a small shift in this M-O bond with increase in calcination temperature suggested the strained LaMnO3 compound. Elemental analysis using the energy dispersive X-ray fluorescence spectrometer (EDXRF) indicated the presence of La and Mn with increase in the Mn contents after calcinations. The oxygen, nitrogen and hydrogen content in the sample were determined from the ONH analysis indicating a decrease in the oxygen content for LMO-800. Well defined porous-foam like morphology of the sample was achieved from scanning electron microscopic (SEM) study, which become compact with calcination process. Magnetic properties were found to transform from the ferromagnetic-to-paramagnetic phase for LMO-UH sample, while reduction in magnetization values and coercivity at low temperatures was obtained for LMO-800 and LMO-1000 samples

Exclusive and Semi-Inclusive B Decays Based on \hspace{0.3cm} b →\rightarrow s \hspace{0.01cm}ηc\eta_c \hspace{0.3cm} Transition

We calculate the semi-inclusive processes B $\rightarrow X_{s} \eta_c$ and relate it to B $\rightarrow X_{s} \psi$ in next to leading order QCD, and show how it can be used to determine an accurate value of $f_{\eta_{c}}$. The exclusive modes B $\rightarrow$ K$\eta_c$ and B $\rightarrow$ K$\psi$ also yield similar results, whereas B $\rightarrow$ K$^*\eta_c$ and B $\rightarrow$ K$^*\psi$ can provide valuable information on hadronic form factors. We also estimate the branching ratios and the ratios of exclusive to inclusive decay modes dominated by b \rightarrow s\e.Comment: 12 pages LATEX, (used new data on B decays, give determination of $f_{\eta_c}$ and more models