Mesino - Antimesino Oscillations

The phenomenological implications of supersymmetric theories with low scale supersymmetry breaking and a squark as the lightest standard model superpartner are investigated. Such squarks hadronize with light quarks, forming sbaryons and mesinos before decaying. Production of these supersymmetric bound states at a high energy collider can lead to displaced jets with large negative impact parameter. Neutral mesino - antimesino oscillations are not forbidden by any symmetry and can occur at observable rates with distinctive signatures. Stop mesino - antimesino oscillations would give a sensitive probe of up-type sflavor violation in the squark sector, and can provide a discovery channel for supersymmetry through events with a same-sign top-top topology.Comment: 4 pages, 1 figure, LaTe

Graphical amplitudes from SCET

We discuss the relationship between the graphical amplitudes T, C, P, ... used to parameterize nonleptonic B decay amplitudes, and matrix elements of operators in the soft-collinear effective theory (SCET) at leading order in \Lambda/m_b. Using the SU(3) flavor symmetry of the weak Hamiltonian we derive all-order constraints on the electroweak penguin contributions to the Wilson coefficients of SCET operators.Comment: 7 pages; one additional relation included, minor corrections. version published in Physics Letters

Obtaining CKM Phase Information from B Penguin Decays

We discuss a method for extracting CP phases from pairs of B decays which are related by flavor SU(3). One decay (B0 -> M1 M2) receives a significant bbar -> dbar penguin contribution. The second (B' -> M1' M2') has a significant bbar -> sbar penguin contribution, but is dominated by a single amplitude. CP phase information is obtained using the fact that the B' -> M1' M2' amplitude is related by SU(3) to a piece of the B0 -> M1 M2 amplitude. The leading-order SU(3)-breaking effect (~25%) responsible for the main theoretical error can be removed. For some decay pairs, it can be written in terms of known decay constants. In other cases, it involves a ratio of form factors. However, this form-factor ratio can either be measured experimentally, or eliminated by considering a double ratio of amplitudes. In all cases, one is left only with a second-order effect, ~5%. We find twelve pairs of B decays to which this method can be applied. Depending on the decay pair, we estimate the total theoretical error in relating the B' -> M1' M2' and B0 -> M1 M2 amplitudes to be between 5% and 15%. The most promising decay pairs are Bd -> pi+ pi- and Bu+ -> K0 pi+, and Bd -> D+ D- and Bd -> Ds+ D- or Bu+ -> Ds+ D0bar.Comment: 38 pages, JHEP format, no figures. Comments added to text regarding most promising decay pairs; references added; conclusions unchange

P and CP violation in B physics

While the Kobayashi--Maskawa single phase origin of CP violation passed its first crucial precision test in $B\to J/\psi K_S$, the chirality of weak $b$-quark couplings has not yet been carefully tested. We discuss recent proposals for studying the chiral and CP-violating structure of these couplings in radiative and in hadronic B decays.Comment: 15 pages, talk at PASCOS'03, Tata Inst., Mumbai, Jan. 200

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

Identification of Neutral B Mesons Using Correlated Hadrons

The identification of the flavor of a neutral $B$ meson can make use of hadrons produced nearby in phase space. Examples include the decay of ``$B^{**}$'' resonances or the production of hadrons as a result of the fragmentation process. Some aspects of this method are discussed, including time-dependent effects in neutral $B$ decays to flavor states, to eigenstates of CP and to other states, and the effects of possible coherence between $B^0$ and $\overline{B}^0$ in the initial state. We study the behavior of the leading hadrons in $b$-quark jets and the expected properties of $B^{**}$ resonances. These are extrapolated from the corresponding $D^{**}$ resonances, of whose properties we suggest further studies.Comment: To be submitted to Phys. Rev. D. 26 pages, LaTeX, figures not included (available upon request). Technion-PH-93-32 / EFI 93-4

Final-State Phases in B→B \to Baryon-Antibaryon Decays

The recent observation of the decay \ob \to \Lambda_c^+ \bar p suggests that related decays may soon be visible at $e^+ e^-$ colliders. It is shown how these decays can shed light on strong final-state phases and amplitudes involving the spectator quark, both of which are normally expected to be small in B decays.Comment: 14 pages, LaTeX, 2 figures, submitted to Phys. Rev. D, references and discussion of helicity amplitudes adde

Possible Large Direct CP Violations in Charmless B-Decays

We discuss the perturbative QCD approach for the exclusive two body B-meson decays to light mesons. We briefly review its ingredients and some important theoretical issues on factorization approach. We show numerical results which are compatible with present experimantal data for the charmless B-meson decays. Specailly we predict the possibility of large direct CP violation effects in $B^0 \to \pi^{+}\pi^{-}$ $(23\pm7$ and $B^0\to K^{+}\pi^{-}$ $(-17\pm5$. In the last section we investigate two methods to determine the weak phases $\phi_2$ and $\phi_3$ from $B \to \pi\pi,K\pi$ processes. We obtain bounds on $\phi_2$ and $\phi_3$ from present experimental measurements.Comment: 18 pages, latex, 8 figures and 8 tables, typos corrected and added more tables and references. Presented at the 3rd workshop on Higher Luminosity B Factory, 6-7 August 2002, Kanagawa, Japan; Submitted to Phys. Rev.

New Physics Effects From B Meson Decays

In this talk, we point out some of the present and future possible signatures of physics beyond the Standard Model from B-meson decays, taking R-parity conserving and violating supersymmetry as illustrative examples.Comment: Talk given at the Sixth Workshop on High Energy Particle Phenomenology (WHEPP-6), Chennai (Madras), India. Includes 2 epsf figure

New Physics in CP Asymmetries and Rare B Decays

We review and update the effects of physics beyond the standard model on CP asymmetries in B decays. These asymmetries can be significantly altered if there are important new-physics contributions to \bqbqbar mixing. This same new physics will therefore also contribute to rare, flavor-changing B decays. Through a study of such decays, we show that it is possible to partially distinguish the different models of new physics.Comment: 42 pages, plain TeX (macros included), 1 figure (included). A few sentences added, references updated. Present manuscript is now identical to the version accepted for publication in Phys. Rev.