We study the Bc,u,d→X(3872)P decays in the perturbative QCD(PQCD)approach,involving the puzzling resonance X(3872),where P represents a light pseudoscalar meson(K orπ).Assuming X(3872)to be a 1++charmonium state,we ...We study the Bc,u,d→X(3872)P decays in the perturbative QCD(PQCD)approach,involving the puzzling resonance X(3872),where P represents a light pseudoscalar meson(K orπ).Assuming X(3872)to be a 1++charmonium state,we obtain the following results.(a)The branching ratios of the Bc+→X(3872)π+and Bc+→X(3872)K+decays are consistent with the results predicted by the covariant light-front approach within errors;however,they are larger than those given by the generalized factorization approach.(b)The branching ratio of the B+→X(3872)K+decay is predicted as(3.8-1.0+1.1)×10-4,which is smaller than the previous PQCD calculation result but still slightly larger than the upper limits set by Belle and BaBar.Hence,we suggest that the B0,+→X(3872)K0,+decays should be precisely measured by the LHCb and Belle II experiments to help probe the inner structure of X(3872).(c)Compared with the Bu,d→X(3872)K decays,the Bu,d→X(3872)πdecays have significantly smaller branching ratios,which drop to values as low as 10-6.(d)The direct CP violations of these considered decays are small(10-3~10-2)because the penguin contributions are loop suppressed compared to the tree contributions.The mixing-induced CP violation of the B→X(3872)K0S decay is highly consistent with the current world average value sin 2β=(69.9±1.7)%.Experimentally testing the results for the branching ratios and CP violations,including the implicit SU(3)and isospin symmetries of these decays,helps probe the nature of X(3872).展开更多
In this study,we investigate quasi-two-body B_((s))→K^(*)γ→Kπγ decays in the perturbative QCD approach.Two-meson distribution amplitudes are introduced to describe the final state interactions of the Kπpair,whic...In this study,we investigate quasi-two-body B_((s))→K^(*)γ→Kπγ decays in the perturbative QCD approach.Two-meson distribution amplitudes are introduced to describe the final state interactions of the Kπpair,which involve time-like form factors and Gegenbauer polynomials.We calculate the CP averaged branching ratios of the B_((s))→K^(*)γ→Kπγ decays.Our results are in agreement with newly updated data measured by Belle Ⅱ.This suggests that it is more appropriate to analyze these quasi-two-body B decays in the three-body framework than the two-body framework.We also predict direct CP asymmetries for the considered decay modes and find that A_CP(B_(u,d)→K^(*)γ→Kπγ) is small and less than 1% in magnitude,whereas A_CP(B_(s)→K^(*)γ→Kπγ)is larger and can reach a few percent.Our predictions can be tested in future B meson experiments.展开更多
基金Supported by the National Natural Science Foundation of China(11347030)the Program of Science and Technology Innovation Talents in Universities of Henan Province(14HASTIT037)。
文摘We study the Bc,u,d→X(3872)P decays in the perturbative QCD(PQCD)approach,involving the puzzling resonance X(3872),where P represents a light pseudoscalar meson(K orπ).Assuming X(3872)to be a 1++charmonium state,we obtain the following results.(a)The branching ratios of the Bc+→X(3872)π+and Bc+→X(3872)K+decays are consistent with the results predicted by the covariant light-front approach within errors;however,they are larger than those given by the generalized factorization approach.(b)The branching ratio of the B+→X(3872)K+decay is predicted as(3.8-1.0+1.1)×10-4,which is smaller than the previous PQCD calculation result but still slightly larger than the upper limits set by Belle and BaBar.Hence,we suggest that the B0,+→X(3872)K0,+decays should be precisely measured by the LHCb and Belle II experiments to help probe the inner structure of X(3872).(c)Compared with the Bu,d→X(3872)K decays,the Bu,d→X(3872)πdecays have significantly smaller branching ratios,which drop to values as low as 10-6.(d)The direct CP violations of these considered decays are small(10-3~10-2)because the penguin contributions are loop suppressed compared to the tree contributions.The mixing-induced CP violation of the B→X(3872)K0S decay is highly consistent with the current world average value sin 2β=(69.9±1.7)%.Experimentally testing the results for the branching ratios and CP violations,including the implicit SU(3)and isospin symmetries of these decays,helps probe the nature of X(3872).
基金Supported in part by the National Natural Science Foundation of China under(11347030)the Program of Science and Technology Innovation Talents in Universities of Henan Province(14HASTIT037)。
文摘In this study,we investigate quasi-two-body B_((s))→K^(*)γ→Kπγ decays in the perturbative QCD approach.Two-meson distribution amplitudes are introduced to describe the final state interactions of the Kπpair,which involve time-like form factors and Gegenbauer polynomials.We calculate the CP averaged branching ratios of the B_((s))→K^(*)γ→Kπγ decays.Our results are in agreement with newly updated data measured by Belle Ⅱ.This suggests that it is more appropriate to analyze these quasi-two-body B decays in the three-body framework than the two-body framework.We also predict direct CP asymmetries for the considered decay modes and find that A_CP(B_(u,d)→K^(*)γ→Kπγ) is small and less than 1% in magnitude,whereas A_CP(B_(s)→K^(*)γ→Kπγ)is larger and can reach a few percent.Our predictions can be tested in future B meson experiments.
