All Results

Charmless B(s) → VV Decays in Factorization-Assisted Topological-Amplitude Approach

Chao Wang; Qi-An Zhang; Ying Li; Cai-Dian LuSubjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

Within the factorization-assisted topological-amplitude approach, we studied the 33 charmless B(s) → VV decays, where V stands for a light vector meson. According to the flavor flows, the amplitude of each process can be decomposed into 8 different topologies. In contrast to the conventional flavor diagrammatic approach, we further factorize each topological amplitude into decay constant, form factors and unknown universal parameters. By χ2 fitting 46 experimental observables, we extracted 10 theoretical parameters with χ2 per degree of freedom around 2. Using the fitted parameters, we calculated the branching fractions, polarization fractions, CP asymmetries and relative phases between polarization amplitudes of each decay mode. The decay channels dominated by tree diagram have large branching fractions and large longitudinal polarization fraction. The branching fractions and longitudinal polarization fractions of color-suppressed decays become smaller. Current experimental data of large transverse polarization fractions in the penguin dominant decay channels can be explained by only one transverse amplitude of penguin annihilation dia-gram. Our predictions of those not yet measured channels can be tested in the ongoing LHCb experiment and the Belle-II experiment in future. |

Constrain the UT angle $\gamma$ by CP violation parameters in $B^0 \to \pi^+ \pi^-$

Qin Qin; Zhi-Tian Zou; Cai-Dian Lu; Ying LiSubjects: Physics >> Nuclear Physics

We calculate the tree and penguin amplitudes in the?B0→π+π??decay channel employing the perturbative QCD factorization approach. Using the amplitudes as input with the theoretical uncertainties sufficiently considered, we constrain the UT angle?γ?to?53?≤γ≤70?, from the measurements of the CP violation parameters?Cπ+π??and?Sπ+π??in?B0→π+π?. The U-spin breaking effect between?B0→π+π??and?B0s→K+K??is estimated to be around 30\%. |

Subjects: Physics >> Nuclear Physics

By assuming that the scalar meson?K?0(1430)?belongs to the first excited states or the lowest lying ground states, we study the pure annihilation-type decays?B→K?±0(1430)K(?)??in the QCD factorization approach. Within the standard model, the branching fractions are at the order of?10?8?10?7, which is possible to be measured in the ongoing LHCb experiment or forthcoming Belle-II experiment. We also study these decays in the family non-universal?Z′?model. The results show that if?mZ′≈600GeV?(ζ=0.02), both the branching fractions and?CPasymmetries of?B????0→K?+0(1430)K??could be changed remarkably, which provides us a place for probing the effect of new physics. These results could be used to constrain the parameters of?Z′?model. |

Spectra of heavy-light mesons in a relativistic model

Jing-Bin Liu; Cai-Dian LuSubjects: Physics >> Nuclear Physics

The spectra and wave functions of heavy-light mesons are calculated within a relativistic quark model, which is derived from the instantaneous Bethe-Salpeter equation by applying the Foldy-Wouthuysen transformation on the heavy quark. The kernel we choose is based on scalar confining and vector Coulomb potentials. The Hamiltonian for heavy-light quark-antiquark system is calculated up to order?1/m2Q. The results are in good agreement with available experimental data except for the masses of the anomalous?D?s0(2317)?and?Ds1(2460)?states. The newly observed charmed meson states can be accommodated successfully in the relativistic model and their assignments are presented, the?D?sJ(2860)?can be interpreted as the?|13/2D1??and?|15/2D3??states being the?JP=1??and?3??members of the 1D family in our model. |

Test flavor SU(3) symmetry in exclusive $\Lambda_c$ decays

Cai-Dian Lu; Wei Wang; Fu-Sheng YuSubjects: Physics >> Nuclear Physics

Flavor SU(3) symmetry is a powerful tool to analyze charmed baryon decays, however its applicability remains to be experimentally validated. Since there is not much data on Ξc decays, various exclusive Λc decays especially the ones into a neutron state are essential for the test of flavor symmetry. These decay modes are also helpful to investigate final state interactions in charmed baryon decays. In this work, we discuss the explicit roles of Λc decays into a neutron in testing the flavor symmetry and exploring final state interactions. The involved decay modes include semileptonic decays, two-body and three-body non-leptonic decays, but all of them have not been experimentally observed to date. |

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