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1.
In this article, we calculate the branching ratios of B→K0^* (1430)K decays by employing the pertur-bative QCD (pQCD) approach at leading order. We perform the evaluations in the two scenarios for the scalar meson spectrum. We find that (i) The leading order pQCD predictions for the branching ratio Br(B^+→K^+K0^*(1430)^0)are in good agreement with the experimental upper limit in both scenarios, while the pQCD predictions for other considered B→K0^*(1430)K decay modes are also presented and will be tested by the LHC experiments; (ii) The annihilation contributions play an important role in these considered decays, for B^0→K0^*(1430)^±K^± decays,for example,which are found to be (1-4)×10^-6.  相似文献   

2.
Based on the assumption of two-quark structure of the scalar meson K*0(1430),we calculate the CP-averaged branching ratios for B→K0*(1430)η(') decays in the framework of the perturbative QCD(pQCD) approach here.We perform the evaluations in two scenarios for the scalar meson spectrum.We find that:(a) the pQCD predictions for Br(B→K*0(1430)η(')) which are about 10-5-10-6,basically agree with the data within large theoretical uncertainty;(b) the agreement between the pQCD predictions and the data in Scenario I is better than that in Scenario II,which can be tested by the forthcoming LHC experiments;(c) the annihilation contributions play an important role for these considered decays.  相似文献   

3.
Based on the assumption of two-quark structure of the scalar meson K*0(1430),we calculate the CP-averaged branching ratios for B→K0*(1430)η(') decays in the framework of the perturbative QCD(pQCD) approach here.We perform the evaluations in two scenarios for the scalar meson spectrum.We find that:(a) the pQCD predictions for Br(B→K*0(1430)η(')) which are about 10-5-10-6,basically agree with the data within large theoretical uncertainty;(b) the agreement between the pQCD predictions and the data in Scenario ...  相似文献   

4.
Based on the assumption of a two-quark structure of the scalar meson f0(980) ,we calculate the branching ratios and CP-violating asymmetries for the four B → f0(980) π and B → f0(980) η^(') decays by employing the perturbative QCD(pQCD) factorization approach. The leading order pQCD predictions for branching ratios are,Br(B^-→ f0(980) π^-) ~ 2.5×10^-6,Br(Bˉ^0 → f0(980) π^0) ~ 2.6×10^-7,Br(Bˉ^0 → f0(980) η) ~ 2.5×10^-7 and Br(Bˉ^0 → f0(980) η ) ~ 6.7×10^-7,which are consistent with both the QCD factorization predictions and the experimental upper limits.  相似文献   

5.
We calculate the CP averaged branching ratios and CP-violating asymmetries for Bs^0 → η'η' and η'η' decays in the perturbative QCD (pQCD) approach here. The pQCD predictions for the C P-averaged branching ratios are Br(Bs^0 → ηη)=(14.2-7.5^+18.0) ×10^-6,Br(Bs^0 → ηη')=(12.4-7.0^+18.2)×10^-6,and Br(Bs^0 → η'η') =(9.2-4.9^+15.3)×10^-6, which agree well with those obtained by employing the QCD factorization approach and also be consistent with available experimental upper limits. The gluonic contributions are small in size: less than 7% for Bs →ηηand ηη' decays, and around 18% for Bs →η'η' decay. The CP-violating asymmetries for three decays are very small: less than 3% in magnitude.  相似文献   

6.
By employing the perturbative QCD (pQCD) factorization approach, we calculate some important next- to-leading-order (NLO) contributions to the two-body charmless hadronic decays B^+ →ρ^+η(') and B^0 → ρ^0(ω, φ)η('), induced by the vertex QCD corrections, the quark-loops as well as the chromo-magnetic penguins. From the numerical results and phenomenological analysis we find that (a) for B^± → ρ^±η(') (B^0 → ρ^0(ω, φ)η(')decays, the partial NLO contributions to branching ratios are small (large) in magnitude; and (b) the pQCD predictions for ACP^dir(B^± → ρ^±η(')) are consistent with the data, while the predicted .ACP(B^0 → ρ^0(ω)η(')) are generally large in magnitude and could be tested by the forthcoming LHCb experiments.  相似文献   

7.
In this paper, we calculate the branching ratios and the direct CP-violating asymmetries for decays B^0 → a0^0(980)π^0, a0^+ (980)π^-, a0^-(980)π^+ and B^- → a0^0 (980)π^-, a0^- (980)π^0 by employing the perturbative QCD (pQCD) factorization approach at the leading order. We found that (a) the pQCD predictions for the branching ratios are around (0.4-2.8) × 10^-6, consistent with currently available experimental upper limits; (b) the CP asymmetries of B^0→ a0^0(980)π^0 and B^- → a0^- (980)π^0 decays can be large, about (70-80)% for α= 100°.  相似文献   

8.
We examine the effects of an unparticle U as a possible source of missing energy in the p-wave decays of a B meson. The dependence of the differential branching ratio on the K0^* (K1) - meson's energy is discussed in the presence of scalar and vector unparticle operators and significant deviation from the standard model value is found after addition of these operators. Finally, we have shown the dependence of the branching ratio for the above-mentioned decays on the parameters of unparticle stuff like effective couplings, cutoff scale Au and the scale dimensions du.  相似文献   

9.
By employing the perturbative QCD (pQCD) factorization approach, we calculate the full leading and the partial next-to-leading order (NLO) contributions to the seven B →πη(′) and η(′)η(′) decays. For B^+→ π+η(′) decays, the pQCD predictions for their decay rates agree very well with the data after the inclusion of the small NLO contributions. For neutral decays, the pQCD predictions are also consistent with the experimental upper limits and can be tested by the LHC experiments. The measured value of dir .Acp^dir(π+η)= 19±7% can also be accommodated by the pQCD approach.  相似文献   

10.
In the two-quark model supposition for K0*(1430), which can be viewed as either the first excited state (ScenarioⅠ) or the lowest lying state (Scenario Ⅱ), the branching ratios and the direct CP-violating asymmetries for decays s0 → K0*0(1430)η (’) are studied by employing the perturbative QCD factorization approach. We find the following results: (a) The CP averaged branching ratios ofs0 → K0*0 (1430)η ands0→ K0*0(1430)η’ are small and both in the order of 10-7 . If one views K0* (1430) as the lowest lying state, B(s0→K0*0(1430)η) ≈ 3.9×10-7 and B(s0→K0*0(1430)η’) ≈ 7.8×10-7.(b) While the direct CP-violating asymmetries of these two decays are not small: if we still take the parameters of K0* (1430) in scenario , ACPdir(s0→K0*0(1430)η) ≈ 56.2% and ACPdir(s0→ K0*0(1430)η’) ≈ 42.4%. (c) The annihilation contributions will play an important role in accounting for future data, because both the branching ratios and the direct CP asymmetries of these two decays are sensitive to the annihilation type contributions.  相似文献   

11.
In this paper,we calculated the B →(J/ψ,ηc) K decays in the perturbative QCD(pQCD) factorization approach with the inclusion of the partial next-to-leading order(NLO) contributions. With the inclusion of the significant enhancement from the NLO vertex corrections,the NLO pQCD predictions for the branching ratios agree with the data within 2σ errors:Br(B0 → J/ψK0) = 5.2-+32..58×10-4,Br(B+ → J/ψK+) = 5.6-+32..79×10-4,Br(B0 →ηcK0) = 5.5-+22..30 × 10-4,Br(B+ →ηcK+) = 5.9-+22..51 × 10-4.  相似文献   

12.
In this paper, we calculate the branching ratios for B^+→ Ds^+η, B^+→ Ds^+η′, B^+→ Ds^(→)η and B^+ → Ds^+η′ decays by employing the perturbative QCD (pQCD) factorization approach. Under the two kinds of η - η′ mixing schemes, the quark-flavor mixing scheme and the singlet-octet mixing scheme, we find that the calculated branching ratios agree well with the currently available experimental upper limits. We also consider the so called "fDs puzzle", by using two groups of parameters about the Ds^(→) meson decay constants, that are fDs = 241 MeV, fDs^→ = 272 MeV and fDs = 274 MeV, fDs^→ = 312 MeV, to calculate the branching ratios for the considered decays. We find that the results change 30%by using these two different kinds of paramters.  相似文献   

13.
By employing the perturbative QCD(pQCD) factorization approach, we calculate the new physics contributions to the four B→Kη()decays in the Standard Model(SM) with a fourth generation of fermions(SM4),induced by the loop diagrams involving t quark. Within the considered parameter space of the SM4 we find that:(a) the next-to-leading order(NLO) pQCD predictions for the branching ratios and CP-violating asymmetries in both the SM and SM4 generally agree with the data within one standard deviation;(b) for Br(B→Kη), the inclusion of the fourth generation contributions can improve the agreement between the theoretical predictions and the data effectively;(c) however, for Br(B → Kη) the decrease due to t loops is disfavored by the data; and,(d) the new physics corrections to the CP-violating asymmetries of the considered decays are only about 10%.  相似文献   

14.
B^0(Bs)→γvv decays are useful to determining the decay constants fB(fBs) and B(Bs) meson wave function. Using the B meson wave function determined in hadronic B(Bs) decays, we study the uncertainties due to the types of B meson wave functions. We find that the branching ratios are sensitive to the type of wave functions and input parameters, but the energy spectrum is independent. The predicted branching ratios are (0.45-1.04)×10^-9 and (2.14-3.27)×10^-8 for B^0 and Bs decay, respectively.  相似文献   

15.
By assuming that the scalar meson K_0~*(1430) belongs to the first excited states or the lowest lying ground states of qq',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 of the order of 10~(-8) 10~(-7),which is possible to measure 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 m_Z≈600 GeV(ζ=0.02),both the branching fractions and CP asymmetries of B~0→K_0~+(1430)K~- could be changed remarkably,which provides us with a place for probing the effect of new physics.These results could be used to constrain the parameters of the Z' model.  相似文献   

16.
Within the framework of the perturbative quantum chromodynamics(PQCD) approach, we study the charmless two-body decays B → a1(1260)K*, b1(1235)K*. Using the decay constants and the light-cone distribution amplitudes for these mesons derived from the QCD sum rule method, we find the following results.(a) Our predictions for the branching ratios are consistent with the QCD factorization(QCDF) results within errors, but much larger than the naive factorization approach calculation values.(b) We predict that the anomalous polarizations occurring in the decays B→φK*, ρK*also happen in B→a1 K*decays, while they do not happen in B→b1 K*decays. Here the contributions from the annihilation diagrams play an important role in explaining the larger transverse polarizations in the B→a1 K*decays, while they are not sensitive to the polarizations for the B→b1 K*decays.(c) Our predictions for the direct C P-asymmetries agree well with the QCDF results within errors. The decaysˉB0→b1+K*-, B-→b10K*-have larger direct C P-asymmetries, which could be measured by the present LHCb experiment and the forthcoming Super-B experiment.  相似文献   

17.
In this article, we assume that the (0^+,1^+) strange-bottom mesons are the conventional bs mesons, and calculate the electromagnetic coupling constants d, g1, g2, and g3 using the light-cone QGD sum rules. Then we study the radiative decays Bs0→Bs^*γ, Bs1→Bsγ, Bs1→Bs^*γ, and Bs1→Bs0γ, and observe that the widths are rather narrow. We can search for the (0^+, 1^+) strange-bottom mesons in the invariant Bsπ^0 and Bs^*π^0 mass distributions in the strong decays or in the invariant Bs^*γ, and Bsγ mass distributions in the radiative decays.  相似文献   

18.
Motivated by the recent LHCb collaboration measurements of charmless three-body decays of ■s meson, we calculate the branching fractions of ■ s →K0π+π-, ■s→K0K+K-, ■s→K0π+K- and ■s→K0K+π- decay modes using the factorization approach.Both the resonant and nonresonant contributions are studied in detail. For the decays ■s→K0π+π- and ■s→K0K+K-, our results agree well with experimental data, and the former is dominated by the K*, while the latter one is dominated by the nonresonant contribution. Considering the flavor S U(3) symmetry violation, the sum of branching fractions of ■s→K0π+K- and ■s→K0K+π-could accommodate the data well too. It should be noted that both branching fractions are sensitive to the scalar density Kπ|ˉsq|0.Furthermore, the resonant contributions are dominated by the scalar K*0(1430). We hope that these branching fractions could be measured individually in the experiments so as to test the factorization approach and the flavor S U(3) asymmetry. Moreover, the direct C P asymmetries of these decays are also investigated, which could be measured in the running LHCb experiment and Super-b factory in the future.  相似文献   

19.
We calculate the branching ratio of rare decay D^0→ФK using the perturbative QCD factorization approach based on kT factorization. Our result shows this branching ratio is (8.7 ± 1.4) x 10^-3, which is consistent with experimental data. We hope that the CLEO-C and BES-Ⅲ can measure it more accurately, which will help us to understand QCD dynamics and D meson weak decays.  相似文献   

20.
We apply perturbative QCD to the radiative decays of charmonia J/ψ and χcJ into light mesons. We perform a complete numerical calculation for the quark-gluon loop diagrams involved in these processes. The calculated J/ψ decay branching ratios into p-wave mesons f2(1270) and f1(1285) fit the data well, while that of fo(980) (if treated as an ss meson) is predicted to be 1.6×10^-4, which implies that f0(1710) can not be the ss or (uu+dd)/√2 meson. Decays of p-wave charmonia χcJ→ρ(ω;φ)γ (J = 0, 1, 2) are also studied, and the branching ratio of χc1→ργ is predicted to be 1.4×10^-5, which may be tested by CLEO-c collaboration and BESlg collaboration with future experiments.  相似文献   

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