ZZH coupling : A probe to the origin of EWSB ?

We argue that the $ZZH$ coupling constitutes a simple probe of the nature of the scalar sector responsible for electroweak symmetry breaking. We demonstrate the efficacy of this measure through an analysis of four-dimensional models containing scalars in arbitrary representation of $SU(2) \times U(1)$, as well as extra-dimensional models with a non-factorizable geometry. A possible role for the $t \bar t H$ couplings is also discussed.Comment: Minor modifications in the text. Version to appear in Nucl. Phys.

Looking for the Top-squark at the Tevatron with four jets

The scalar partner of the top quark is relatively light in many models of supersymmetry breaking. We study the production of top squarks (stops) at the Tevatron collider and their subsequent decay through baryon-number violating couplings such that the final state contains no leptons. Performing a detector-level analysis, we demonstrate that, even in the absence of leptons or missing energy, stop masses upto 210 \gev/c^2 can be accessible at the Tevatron.Comment: 4 pages, 4 embedded figures, RevTe

Higgs Boson Signals in Three b-jet Final States at the Fermilab Tevatron

At the Fermilab Tevatron, final states with three tagged b-jets could play an important role in searches for a Higgs boson with mass in the range 100-300 GeV. These signals arise from gb fusion and we demonstrate their observability in the limit of a large b-quark Yukawa coupling. Rather promising discovery limits on such a coupling are obtained and consequent effects on the parameter space of the Higgs-boson sector in the MSSM are discussed.Comment: 4 pages, 4 postscript figures, RevTeX (style files included

Search for the lightest scalar top quark in R-parity violating decays at the LHC

The scalar partner of the top quark (the stop) is relatively light in many models of supersymmetry breaking. We study the production of stops at the Large Hadron Collider (LHC) and their subsequent decays through baryon-number violating couplings such that the final state contains no leptons. A detailed analysis performed using detector level observables demonstrate that stop masses upto \sim 600 \gev may be explored at the LHC depending on the branching ratios for such decays and the integrated luminosity available. Extended to other analogous scenarios, the analysis will, generically, probe even larger masses.Comment: 11 pages, 6 fig

A supersymmetric resolution of the anomaly in charmless nonleptonic BB-decays

We examine the large branching ratio for the process $B\to \eta^{\prime} K$ from the standpoint of R parity violating supersymmetry. We have given all possible $R_p$ violating contributions to $B\to \eta^{\prime} K$ amplitudes. We find that only two pairs of $\lambda^{\prime}$-type $R_p$ violating couplings can solve this problem after satisfying all other experimental bounds. We also analyze those modes where these couplings can appear, {\em e.g.}, $B^\pm \to \pi^{\pm}K^0$, $B^{\pm,0} \to K^{*\pm,0} \eta^{(\prime)}$, $B^{\pm} \to\phi K^{\pm}$ etc., and predict their branching ratios. Further, one of these two pairs of couplings is found to lower the branching ratio of $B^{\pm}\to\phi K^\pm$, thereby allowing larger $\xi\equiv{1\over N_c}$. This allows us to fit $B^{\pm}\to \omega K^{\pm}$ and $B^{\pm}\to \omega \pi^{\pm}$, which could not be done in the SM framework.Comment: 12 pages, 5 figure