Charmless hadronic B decays and the recent CLEO data

In the light of recent experimental data from the CLEO Collaboration we study, the decays of B mesons to a pair of pseudoscalar (P) mesons, and a vector (V) meson and a pseudoscalar meson, in the framework of factorization. In order to obtain the best fit for the recent CLEO data, we critically examine the values of several input parameters to which the predictions are sensitive. These input parameters are the form factors, the strange quark mass, $\xi \equiv 1/ N_c$ (N_c is the effective number of color), the CKM matrix elements and in particular, the weak phase $\gamma$. It is possible to give a satisfactory account of the recent experimental results in $B \to PP$ and VP decays, with constrained values of a \emph{single} $\xi$. We identify the decay modes in which CP asymmetries are expected to be large.Comment: 24 pages, 11 figures, LaTex; Version to appear in Phys. Rev.

Charmless Non-Leptonic B Decays and R-parity Violating Supersymmetry

We examine the charmless hadronic B decay modes in the context of R-parity violating (\rpv) supersymmetry. We try to explain the large branching ratio (compared to the Standard Model (SM) prediction) of the decay $B^{\pm}\to \eta' K^{\pm}$. There exist data for other observed $\eta^{(\prime)}$ modes and among these modes, the decay $B^{0}\to \eta K^{*0}$ is also found to be large compared to the SM prediction. We investigate all these modes and find that only two pairs of \rpv coupling can satisfy the requirements without affecting the other B\ra PP and B\ra VP decay modes barring the decay B\ra\phi K. From this analysis, we determine the preferred values of the \rpv couplings and the effective number of color $N_c$. We also calculate the CP asymmetry for the observed decay modes affected by these new couplings.Comment: 14 pages, 7 figures; revtex; version published in Phys. Lett.

Hadronic B Decays to Charmless VT Final States

Charmless hadronic decays of B mesons to a vector meson (V) and a tensor meson (T) are analyzed in the frameworks of both flavor SU(3) symmetry and generalized factorization. We also make comments on B decays to two tensor mesons in the final states. Certain ways to test validity of the generalized factorization are proposed, using $B \to VT$ decays. We calculate the branching ratios and CP asymmetries using the full effective Hamiltonian including all the penguin operators and the form factors obtained in the non-relativistic quark model of Isgur, Scora, Grinstein and Wise.Comment: 27 pages, no figures, LaTe

Einstein Manifolds As Yang-Mills Instantons

It is well-known that Einstein gravity can be formulated as a gauge theory of Lorentz group where spin connections play a role of gauge fields and Riemann curvature tensors correspond to their field strengths. One can then pose an interesting question: What is the Einstein equations from the gauge theory point of view? Or equivalently, what is the gauge theory object corresponding to Einstein manifolds? We show that the Einstein equations in four dimensions are precisely self-duality equations in Yang-Mills gauge theory and so Einstein manifolds correspond to Yang-Mills instantons in SO(4) = SU(2)_L x SU(2)_R gauge theory. Specifically, we prove that any Einstein manifold with or without a cosmological constant always arises as the sum of SU(2)_L instantons and SU(2)_R anti-instantons. This result explains why an Einstein manifold must be stable because two kinds of instantons belong to different gauge groups, instantons in SU(2)_L and anti-instantons in SU(2)_R, and so they cannot decay into a vacuum. We further illuminate the stability of Einstein manifolds by showing that they carry nontrivial topological invariants.Comment: v4; 17 pages, published version in Mod. Phys. Lett.

Absorption cross section in warped AdS_3 black hole revisited

We investigate the absorption cross section for minimal-coupled scalars in the warped AdS_3 black hole. According to our calculation, the cross section reduces to the horizon area in the low energy limit as usually expected in contrast to what was previously found. We also calculate the greybody factor and find that the effective temperatures for the two chiral CFT's are consistent with that derived from the quasinormal modes. Observing the conjectured warped AdS/CFT correspondence, we suspect that a specific sector of the CFT operators with the desired conformal dimension could be responsible for the peculiar thermal behaviour of the warped AdS_3 black hole.Comment: 16+1 pages, typos corrected, references and footnotes adde

A View of the Dutch IPO Cathedral

This is the Keynote Address for IPOs and the Internet Age: The Case for Updated Regulations, a symposium held at The Ohio State University Michael E. Moritz College of Law. Initial public offerings ( IPOs ) are an exercise in asymmetrical valuation. One mechanism for bridging these asymmetries is a private financial intermediary to conduct price discovery by meeting with preferred investors. An alternate mechanism is an auction, such as a descending-bid or Dutch procedure, to conduct price discovery by soliciting bids from all prospective investors. Recent disenchantment with the relationship between issuers and intermediaries has prompted some to hail (online) auction-based IPOs. This switch, however, incurs a variety of legal costs that may justify broader mandatory disclosure and state intervention. The legal costs of auction-based IPOs can be gleaned from examining various international regulatory regimes. To comparatively evaluate these regimes, this article introduces a paradigmatic framework derived from the classic tri-tiered schema that Guido Calabresi and A. Douglas Melamed formulated for legal entitlements. By conceptualizing IPOs as a problem of asymmetrically-valued shares, different kinds of regulations can assume the form of property, liability, and inalienability rules. The distinctions between these rules explain variations within the regulatory schemes of France, Israel, and Taiwan, the last bastions of auction-based IPOs, and evince the legal price that must be paid for the United States to offer an auction-based alternative to bookbuilding