7,277 research outputs found
Study of the weak annihilation contributions in charmless decays
In this paper, in order to probe the spectator-scattering and weak
annihilation contributions in charmless (where stands for a
light vector meson) decays, we perform the -analyses for the end-point
parameters within the QCD factorization framework, under the constraints from
the measured , , and
decays. The fitted results indicate that the end-point
parameters in the factorizable and nonfactorizable annihilation topologies are
non-universal, which is also favored by the charmless and (where
stands for a light pseudo-scalar meson) decays observed in the previous
work. Moreover, the abnormal polarization fractions measured by the LHCb
collaboration can be reconciled through the weak annihilation corrections.
However, the branching ratio of decay exhibits a
tension between the data and theoretical result, which dominates the
contributions to in the fits. Using the fitted end-point
parameters, we update the theoretical results for the charmless
decays, which will be further tested by the LHCb and Belle-II experiments in
the near future.Comment: 31 pages, 4 figures, 6 table
The role of inter-well tunneling strength on coherence dynamics of two-species Bose-Einstein condensates
Coherence dynamics of two-species Bose-Einstein condensates in double wells
is investigated in mean field approximation. We show that the system can
exhibit decoherence phenomena even without the condensate-environment coupling
and the variation tendency of the degree of coherence depends on not only the
parameters of the system but also the initial states. We also investigate the
time evolution of the degree of coherence for a Rosen-Zener form of tunneling
strength, and propose a method to get a condensate system with certain degree
of coherence through a time-dependent tunneling strength
Further understanding of the non- decays of
We provide details of the study of non- decays into
, where and denote light vector meson and pseudoscalar meson,
respectively. We find that the electromagnetic (EM) interaction plays little
role in these processes, while the strong interaction dominates. The strong
interaction can be separated into two parts, i.e. the short-distance part
probing the wave function at origin and the long-distance part reflecting the
soft gluon exchanged dynamics. The long-distance part is thus described by the
intermediate charmed meson loops. We show that the transition of can be related to such that the parameters in our model
can be constrained by comparing the different parts in to
those in . Our quantitative results confirm the findings of
[Zhang {\it et al.}, Phys. Rev. Lett. 102, 172001 (2009)] that the
OZI-rule-evading long-distance strong interaction via the IML plays an
important role in decays, and could be a key towards a full
understanding of the mysterious non- decay mechanism.Comment: 11 pages, 4 figures, version to appear in Phys. Rev.
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