Narrow Results

We determine the weak phases and the amplitudes by proposing an parametrization to each topologies of amplitudes in power of Wolfenstein parameter λ ~ 0.22. Comparing this parametrization with the experimental data, we can obtain the phase ϕ₃ from the B → Kπ data up to theoretical uncertainty of O(λ³) ~ 5%. We find that these solutions indicate a large color-suppressed tree amplitude. The extraction of the phase ϕ₂ and ϕ₃ are consistent with the global unitarity triangle fit.

A study of the decay is performed using 81 fb^-1 of data collected at the ϒ(4S) with the BABAR detector at PEP-II. The branching fraction of is measured to be (6.7 ± 0.9 ± 0.6) × 10⁶. An upper limit on the branching fraction of , where Θ*⁺⁺ is a narrow state decaying to pK⁺, is set to be 1.5 × 10^-7 for 1.43 < m(Θ*⁺⁺) < 1.85 GeV/c² at 90% confidence level. All results are preliminary.

The status of exclusive two-body and three-body baryonic B decays is reviewed. The threshold enhancement effect in the dibaryon invariant mass and the angular distributions in the dibaryon rest frame are stressed and explained. Weak radiative baryonic B decays mediated by the electromagnetic penguin process b→sγ are discussed. Puzzles with the correlation observed in decay and the unexpectedly large rate observed for are examined. The former may indicate that the system is produced through some intermediate states, while the latter implies the failure of naive factorization for modes and may hint at the importance of final-state rescattering effects.

New results on rare decays of B mesons and τ leptons are summarised. Measurement are generally in excellent agreement with the Standard Model predictions, the only exceptions being the polarisation of vector particles in B decays and the non-appearance of CP violation in B^± → K^±π⁰.

We show that Supersymmetric effects driven by penguin contributions to the $b\to c\tau {\nu }_{\tau }$ transition are able to account simultaneously for a sizeable increase of both branching ratios of $\bar{B}\to D\tau {\bar{\nu }}_{\tau }$ and $\bar{B}\to D^{\ast }\tau {\bar{\nu }}_{\tau }$ with respect to the Standard Model predictions, thereby approaching their experimentally measured values. We emphasize that a light chargino and neutralino, with masses less than 300 GeV, in addition to a large stau/sneutrino mass and a large $tan\beta$, are essential for enhancing the effect of the lepton penguin $\tau {\nu }_{\tau }{W}^{\pm }$, which is responsible for the improved theoretical predictions with respect to current data.

Lepton Flavor Universality Violation (LFUV) in $B$ decays in both neutral $b\to s{l}^{+}{l}^{-}$ and charged $b\to cl{\bar{\nu }}_l$ processes observed in the ratios $R_{K^{(\ast )}}$ and $R_{D^{(\ast )}}$ is investigated in the framework of a model based on the extended symmetry gauge $SU{(3)}_C\otimes SU{(3)}_L\otimes U{(1)}_X$ whose leptonic sector consists of five triplets. It is shown that in order to explain the experimentally observed deviations from the Standard Model in these flavor changing transitions, a nonminimal version of the model has to be considered. We investigate the ability of this model in accommodating the model-independent scenarios currently favored by global fits.

New results on rare decays of B mesons and τ leptons are summarised. Measurement are generally in excellent agreement with the Standard Model predictions, the only exceptions being the polarisation of vector particles in B decays and the non-appearance of CP violation in B^± → K^±π⁰.

We study B⁰ → J/ψπ⁺ π⁻ decays, investigating the f₀(980) and f₀(500) production by taking into account the final state interaction between the pseudoscalar mesons in the framework of chiral unitary theory. We obtain the π⁺π⁻ invariant mass distribution for these decay processes, which allows us to compare directly to the experiments and test the nature of the scalar resonances.