B meson decays to baryons in the diquark model

We study B meson decays to two charmless baryons in the diquark model, including strong and electroweak penguins as well as the tree operators. It is shown that penguin operators can enhance \bar{B} \to \Bb_s \bar{\Bb} considerably, but affect \bar{B} \to \Bb_1 \bar{\Bb}_2 only slightly, where \Bb_{(1,2)} and \Bb_s are non-strange and strange baryons, respectively. The $\gamma$ dependence of the decay rates due to tree-penguin interference is illustrated. In principle, some of the \Bb_s \bar{\Bb} modes could dominate over \Bb_1 \bar{\Bb}_2 for $\gamma > 90^\circ$, but in general the effect is milder than their mesonic counterparts. This is because the $O_6$ operator can only produce vector but not scalar diquarks, while the opposite is true for $O_1$ and $O_4$. Predictions from diquark model are compared to those from the sum rule calculation. The decays \bar{B} \to \Bb_s \bar{\Bb}_s and inclusive baryonic decays are also discussed.Comment: 9 pages, 6 figures, Revte

Neutrino Masses in a 5D SU(3)WSU(3)_W TeV Unification Model

We study the generation of neutrino masses in the $SU(3)_W$ electroweak unified theory in $M_4\times S_1/(Z_2\times Z'_2)$ spacetime. By appropriate orbifolding, the bulk symmetry $SU(3)_W$ is broken into $SU(2)_L \times U(1)_Y$ at one of the fixed points, where the quarks reside. The leptons form $SU(3)_W$ triplets, localized at the other symmetric fixed point. The fermion masses arise from the bulk Higgs sector containing a triplet and an anti-sextet. We construct neutrino Majorana masses via 1-loop quantum corrections by adding a parity odd bulk triplet scalar. No right-handed neutrino is needed. The neutrino mass matrix is of the inverted hierarchy type. We show that the model can easily accommodate the bi-large mixing angle solution favored by the recent neutrino experiments without much fine tuning of parameters. The constraints from \mu\ra 3e transition and neutrinoless double beta decays are discussed.Comment: 14 pages, 4 figure

Bulk Higgs Boson Decays in Brane Localized Gravity

We embed the Standard Model in the Randall-Sundrum model of 5 dimensional brane localized gravity. The SM gauge and chiral fermion fields are restricted on the 4D visible brane whereas the Higgs and the right-handed neutrino are assumed to be 5D bulk fields. We calculate the effective couplings of the lowest mass Higgs field to the SM fermions and to the gauge bosons and find that the couplings are enhanced. Furthermore, the invisible decay width of a bulk Higgs of mass 150 GeV is shown to be large.Comment: 14 pages, 2 postscript figures, minor typos corrected, two references added, to appear in Physics Letters

QCD Corrections to b→sγγb\to s\gamma\gamma and Exclusive Bs→γγB_s\to \gamma\gamma Decay

The short distance QCD corrections to $b\to s\gamma \gamma$ are calculated in the leading logarithmic approximation. The equivalence of operator basis reduction for S-matrix elements by using the equations of motion or by proving a low energy theorem is discussed. We apply the above results to the exclusive $B_s\to \gamma\gamma$ decay. The branching ratio of this decay is found to be $5\times 10^{-7}$ in the Standard Model. We also found that QCD corrections modify considerably the ratio between CP-even and CP-odd two-photon amplitudes.Comment: revtex, 15 pages, 2 figures; revised version with corrections from electroweak penguin discussed, the conclusion remains unchange

Solutions to the R_b, R_c and alpha_s puzzles by Vector Fermions

We propose two minimal extensions of Standard Model, both of which can easily accommodate the recent puzzling observations about the excess in $R_b$, the deficit in $R_c$ and the discrepancy in the low energy and high energy determinations of $\alpha_{s}$. Each model requires three additional heavy vectorial fermions in order to resolve the puzzles. The current phenomenological constraints and the new potential phenomena are also discussed.Comment: 12 pages, in LaTeX, postscript file also appear http://www.uic.edu/~keung/pub/rbrc.p

Probing for the Charm Content of BB and Υ\Upsilon Mesons

A slow $J/\psi$ bump exists in the inclusive $B\to J/\psi + X$ spectrum, while the softness of $J/\psi$ spectrum in $\Upsilon(1S) \to J/\psi + X$ decay is in strong contrast with expectations from color octet mechanism. We propose {\it intrinsic} charm as the explanation:the former is due to $\bar B\to J/\psi D \pi$,with three charm quarks in the final state; the latter is just a small fraction of $\Upsilon(1S) \to (c\bar c)_{\rm slow} + 2$"jet" events, where the slow moving $c\bar c$ system evolves into $D^{(*)}$ pairs. Experimental search for these phenomena at B Factories and the Tevatron is strongly urged, as the implications go beyond QCD.Comment: 4 pages, REVTEX, 10 eps figures included. Major revision with more discussions on the rescattering background, and a reappraisal of the Upsilon(1S) decay in the presence of intrinsic charm, leading to a change in Titl

A new era for studies on cross-Strait relations: introduction

After more than half a century’s separation, interaction between China and Taiwan has increased and has progressively changed from a politico-economic interaction to a more civic interaction. Scholars working on cross-Strait relations have recently begun to pay attention to the civic influence of Taiwanese businesses on the relationship. Some emphasize the importance of sub-governmental interactions in the process of cross-Strait integration. Others assert that Taiwanese businesses can exercise economic leverage to constrain the Chinese government in cross-Strait policymaking. These scholars stress bottom–up processes by observing current phenomena, then deducing the emerging pattern of cross-Strait relations that may be influenced by business activities. Taking account of changing trends in scholarly discussions of the cross-Strait relationship, this special issue of China Information presents current research in this field. Unlike studies on top–down processes that affect political and economic interactions between China and Taiwan, several contributions in the special issue highlight bottom–up mechanisms affecting such interactions by examining the identity of Taiwanese businesspeople and migrants, as well as the activities and implications of Taiwanese charitable organizations operating in China. This issue focuses not only on the impact of China on Taiwan, but also the impact of Taiwanese investments, migrants, and exports on Chinese society