共查询到20条相似文献,搜索用时 15 毫秒
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Using the next-to-leading-order low-energy effective Hamiltonian, the CP asymmetries for -meson decays into meson pairs are calculated in the spectator approximation. We do not compute the hadronic matrix elements
directly; instead, we use the amplitude ratios to estimate the CP asymmetries. This is quite different from previous treatments
in the literature. The values of the momentum squared carried by the virtual particles in timelike penguin diagrams are also
carefully discussed. From our calculated results, the best decay modes to observe CP violation in decays would be , , , , and , each of them needs about of events in experiment.
Received: 17 December 1998 / Published online: 30 June 1999 相似文献
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C. J. Gilmour 《Zeitschrift fur Physik C Particles and Fields》1983,18(2):163-172
Two-body weak decays of heavy mesons are studied using a simple non-relativistic model for the meson-quark-antiquark vertex. Numerical results are compared with experimental data where possible. The properties of the amplitudes calculated suggest that dynamical factors are important in determining the nature of these decays. 相似文献
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We study two-body charmless hadronic decays of B mesons to a pseudoscalar meson (P) and a tensor meson (T) in the frameworks of both flavor SU(3) symmetry and generalized factorization. Certain ways to test the validity of the
generalized factorization are proposed, based on the flavor SU(3) analysis. We present a set of relations between a flavor
SU(3) amplitude and the corresponding amplitude in the generalized factorization which bridge both approaches in decays. The branching ratios and CP asymmetries are calculated using the full effective Hamiltonian including all the penguin operators and the form factors obtained in the non-relativistic quark model of Isgur, Scora, Grinstein and Wise. We identify
the decay modes in which the branching ratios and CP asymmetries are expected to be relatively large.
Received: 6 July 2001 / Revised version: 8 October 2001 / Published online: 30 November 2001 相似文献
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ALEPH Collaboration D. Buskulic D. Casper I. De Bonis D. Decamp P. Ghez C. Goy J. -P. Lees A. Lucotte M. -N. Minard et al. 《Zeitschrift fur Physik C Particles and Fields》1995,69(1):379-392
A data sample of about 3.0 million hadronicZ decays collected by the ALEPH experiment at LEP in the years 1991 through 1994 is used to make an inclusive selection of
B hadron events. In this event sample 4227±140±252B* mesons in the decayB*→Bγ and 1944±108±161B**
u,d
mesons decaying into a B meson and a charged pion are reconstructed. Here and in the followingB**
u,d
denotes the eightL=1(bū) and (bd) states and their charge conjugate.
For the well establishedB* meson the following quantities are obtained:ΔM=M
B*−MB=(45.30±0.35±0.87) MeV/c2 andN
B*/(N
B+N
B*)=(77.1±2.6±7.0)%. The angular distribution of the photons in theB* rest frame is used to measure the relative contribution of longitudinalB* polarization states to beσ
L/(σ
L+σ
T)=(33±6±5)%. 相似文献
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H. Fritzsch 《Physics letters. [Part B]》1979,86(2):164-166
The weak decays B→ψ(J) + X are investigated. It is argued that these decays are dominated by B→ψ(J)Kπ (branching ratio of about 1%). Detailed predictions for these decays are made. 相似文献
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We investigate nonfactorizable contributions to charm meson decays into D → ππ/K K?/K K?*/K? K*/D → K*K?* modes. Obtaining the contributions from spectatorquark diagrams for N c = 3, we determine the nonfactorizable isospin amplitudes required to explain the data for these modes. For these decays, we observe that ππ, πρ, decay modes favor a nonfactorizable-isospin-amplitudes ratio A 0 nf /A 2 nf equal to (1.123±0.158) and for K K?, K K?*, K? K* and K*K?* modes, the ratio of nonfactorizable amplitudes A 0 nf and A 1 nf turns out to be unity. 相似文献
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V. A. Saleev 《Physics of Atomic Nuclei》2001,64(11):2027-2031
On the basis of the model of hard one-gluon exchange, the two-particle hadronic decays of B c mesons into S-and P-wave charmonium states, B c → X cc π(ρ), are considered at high momentum transfers and in the nonrelativistic approximation. It is shown that the width with respect to B c-meson decay into S-wave charmonium states is two times greater than the width with respect to B c-meson decay into P-wave states and that the yield of J/ψ mesons in the cascade processes of B c-meson decay via the formation and radiative decay of P-wave charmonium states is approximately 8% of the yield of directly produced J/ψ mesons. 相似文献
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《Zeitschrift fur Physik C Particles and Fields》1997,76(3):425-440
Results are presented on the production of excited charm and excited charm-strange mesons in hadronic Z0 decays. The results are obtained from approximately 4.3 million hadronic Z0 decays, collected on or near the Z0 resonance using the OPAL detector at LEP. The D0 1(2420) and D*0 2 (2460) mesons are reconstructed in the D*+π-. final state and their separate production rates in charm fragmentation and in weak decays of b-hadrons are determined. Assuming that the decay widths of these mesons are saturated by the allowed D*π and Dπ final states, the charm hadronization fractions and the inclusive branching ratios of b-hadrons to these neutral P-wave charm mesons are determined to be 相似文献
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S. Ya. Kotkovskii 《JETP Letters》1997,65(10):768-772
The probability of inclusive semileptonic decay of B mesons is calculated in the constituent-quark model. A compact formula is obtained for the differential decay width of a
B meson in terms of the corresponding decay width of a free b quark and the wave function of the internal motion of the quarks in the B meson. Numerical values of semileptonic-decay widths are obtained for a series of models of the wave function.
Pis’ma Zh. éksp. Teor. Fiz. 65, No. 10, 734–737 (25 May 1997) 相似文献