arXiv subjects
Publications and source records attributed to O. Leitner.
A complete study of the process B to pi+ pi- V(V=1--) is performed both in the framework of the helicity formalism and the effective lagrangian approach. Emphasis is put on the factorization hypothesis and the importance of the rho0- omega mixing in enhancing the direct CP violation. New results involving some branching ratios and the ratio of the Penguin/Tree amplitude are given in details.
Simulation methods for the decays $ B \to π^+ π^- V$, where $V$ is a $1^{--}$ vector-meson, are presented in detail. Emphasis is put on the use of the helicity formalism and the use of effective Lagrangians. We show the importance of ${ρ^{0}}-ω$ mixing in enhancing the direct $CP$ violation (DCPV) when the pion-pion invariant mass is near the mass of the $ω$.
Direct CP violation in the hadronic decays $\Bar{B}^{0} \to π^{+}π^{-} π^{0}$ is investigated near the peak of the $ρ^{0}$ taking into account the effect of $ρ- ω$ mixing. Branching ratios for processes $B^{\pm,0} \to ρ^{\pm,0}π^{\pm,0}$ and $B^{-} \to ωπ^{-}$ are calculated as well. We find that the CP violating asymmetry is strongly dependent on the CKM matrix elements. For a fixed $N_{c}^{eff}$, the CP violating asymmetry, $a$, has a maximum of order -40% to -70% for $\Bar{B}^{0} \to ρ^{0}(ω) π^{0}$ when the invariant mass of the $π^{+}π^{-}$ pair is in the vicinity of the $ω$ resonance. The sensitivity of the asymmetry to $N_{c}^{eff}$ is small in that case. Moreover, we find that in the range of $N_{c}^{eff}$ which is allowed by the most recent experimental branching ratios from the BABAR, BELLE and CLEO Collaborations, the sign of $\sin δ$ is always positive. Thus, a measurement of direct CP violation in decays $\Bar{B}^{0} \to π^{+}π^{-} π^{0}$ would remove the mod$(π)$ ambiguity in the determination of the CP violating phase angle $α$.
Based on the QCD factorization approach we analyse the branching ratios for the channel $B \to ρπ$. From the comparisons with experimental data provided by CLEO, BELLE and BABAR we constrain the form factor $F^{B \to π}(m_ρ^{2})$ and propose boundaries for this form factor depending on the CKM matrix element parameters $ρ$ and $η$.
We present a detailed study of direct CP violation and branching ratios in the channels $B^{0,\pm} \to π^{+}π^{-} V^{0,\pm}$, where $V$ is a vector meson ($K^{* 0,\pm}$ or $ρ^{\pm}$). Emphasis is placed upon the important role played by ${ρ^{0}}-ω$ mixing effects in the estimation of the CP-violating asymmetry parameter, $a_{cp}$, associated with the difference of $B$ and $\bar B$ decay amplitudes. A thorough study of the helicity amplitudes is presented as a function of the pion-pion invariant mass. All of the calculations and simulations considered correspond to channels which will be analyzed at the LHCb facility.
In this paper, a complete description of the channels $B \to V_1 V_2$ is given. Emphasis is put on the determination of the dynamical density matrix which elements are computed according to the Wilson operator product expansions entering into the formulation of the weak effective hamiltonian. \vskip 0.3cm Kinematical consequences related to the particular channel $B \to K^* ρ^0 (ω)$ are described in details.
We investigate in a phenomenological way, direct CP violation in the hadronic decays $B^{\pm,0} \to π^{+} π^{-} K^{\pm,0}$ where the effect of $ρ- ω$ mixing is included. If $N_{c}^{eff}$ (the effective parameter associated with factorization) is constrained using the most recent experimental branching ratios (to $ρ^{0}K^{0}, ρ^{\pm}K^{\mp}, ρ^{\pm}K^{0}, ρ^{0} K^{\pm}$ and $ωK^{\pm}$) from the BABAR, BELLE and CLEO Collaborations, we get a maximum CP violating asymmetry, $a_{max}$, in the range -25% to $+49%$ for $B^{-} \to π^{+}π^{-} K^{-}$ and -24% to $+55%$ for ${\Bar B}^{0} \to π^{+}π^{-} {\Bar K}^{0}$. We also find that CP violation is strongly dependent on the Cabibbo-Kobayashi-Maskawa matrix elements. Finally, we show that the sign of $\sin δ$ is always positive in the allowed range of $N_{c}^{eff}$ and hence, a measurement of direct $CP$ violation in $B^{\pm,0} \to π^{+} π^{-} K^{\pm,0}$ would remove the mod$(π)$ ambiguity in ${\rm arg}[ - \frac{V_{ts}V_{tb}^{\star}}{V_{us}V_{ub}^{\star}}]$.
We study direct CP violation in the hadronic decay $B^{\pm} \to ρ^{0}π^{\pm}$, including the effect of $ρ- ω$ mixing. We find that the CP violating asymmetry is strongly dependent on the CKM matrix elements, especially the Wolfenstein parameter $η$. For fixed $N_{c}$ (the effective parameter associated with factorization), the CP violating asymmetry, $a$, has a maximum of order $30%-50%$ when the invariant mass of the $π^{+}π^{-}$ pair is in the vicinity of the $ω$ resonance. The sensitivity of the asymmetry, $a$, to $N_{c}$ is small. Moreover, if $N_{c}$ is constrained using the latest experimental branching ratios from the CLEO collaboration, we find that the sign of $\sin δ$ is always positive. Thus, a measurement of direct CP violation in $B^{\pm} \to ρ^{0}π^{\pm}$ would remove the mod$(π)$ ambiguity in ${\rm arg}[ - \frac{V_{td}V_{tb}^{\star}}{V_{ud}V_{ub}^{\star}}]$.