Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userLooking for meson molecules in B decays
159
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We discuss the possibility of observing a loosely bound molecular state in a B three-body hadronic decay. In particular we use the QCD sum rule approach to study a $eta^prime-pi$ molecular current. We consider an isovector-scalar $I^G J^{PC}= 1^-~0^{++}$ molecular current and we use the two-point and three-point functions to study the mass and decay width of such state. We consider the contributions of condensates up to dimension six and we work at leading order in $alpha_s$. We obtain a mass around 1.1 GeV, consistent with a loosely bound state, and a $eta^prime-pirightarrow K^+ K^-$ decay width around 10 MeV.
rate research
Read More
We review the two and three-body baryonic $B$ decays with the dibaryon (${bf Bbar B}$) as the final states. Accordingly, we summarize the experimental data of the branching fractions, angular asymmetries, and $CP$ asymmetries. In the approach of perturbative QCD counting rules, we study the three-body decay channels. Using the $W$-boson annihilation (exchange) mechanism, the branching fractions of $Bto {bf B bf bar B}$ are shown to be interpretable. In particular, we review the $CP$ asymmetries of $Bto {bf Bbar B}M$, which are promising to be measured by the LHCb and Belle II experiments.
This article summarizes recent developments in $Bto D^{(ast)}tau u$ decays. We explain how to extract the tau leptons production properties from the kinematics of its decay products. The focus is on hadronic tau decays, which are most sensitive to the tau polarizations. We present new results for effects of new physics in tau polarization observables and quantify the observation prospects at BELLE II.
We provide a comprehensive test of factorization in the heavy-heavy $B$ decays motivated by the recent experimental data from BELLE and BABAR collaborations. The penguin effects are not negligible in the B decays with two pseudoscalar mesons. The direct CP asymmetries are found to be a few percent. We give estimates on the weak annihilation contributions by analogy to the observed annihilation-dominated processes. The $N_c$ insensitivity of branching ratios indicates that the soft final state interactions are not dominant. We also study the polarizations in $Bto D^*D_{(s)}^*$ decays. The power law shows that the transverse perpendicular polarization fraction is small. The effects of the heavy quark symmetry breaking caused by the perturbative QCD and power corrections on the transverse polarization are also investigated.
To date, the weak-phase $gamma$ has been measured using two-body $B$-meson decays such as $Bto D K$ and $Bto Dpi$, whose amplitudes contain only tree-level diagrams. But $gamma$ can also be extracted from three-body charmless hadronic $B$ decays. Since the amplitudes for such decays contain both tree- and loop-level diagrams, $gamma$ obtained in this way is sensitive to new physics that can enter into these loops. The comparison of the values of $gamma$ extracted using tree-level and loop-level methods is therefore an excellent test for new physics. In this talk, we will show how U-spin and flavor-SU(3) symmetries can be used to develop methods for extracting $gamma$ from $Bto Kpipi$ and $Bto KK{bar K}$ decays. We describe a successful implementation of the flavor-SU(3) symmetry method applied to BaBar data.
The approximate symmetry of the strong interactions under isospin transformations is among the most precise tools available to control hadronic matrix elements. It is crucial in extracting fundamental parameters, but also provides avenues for the search of phenomena beyond the Standard Model. The precision of the resulting predictions requires special care when determining the quantities they are to be tested with. Specifically, in the extraction of branching ratios often isospin symmetry is assumed at one point or another implicitly, implying a significant bias for precision analyses. We extract a bias-free value for the production asymmetry between charged and neutral $B$ meson pairs at $B$ factories and discuss its consequences for the determination of branching fractions generally, and isospin-violating observables like the rate asymmetries in B -> J/psi K or B -> K* gamma decays specifically.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
