356 research outputs found
The kappa in E791 data for D->K-pi-pi
A combined fit is made to E791 data on D->K-pi-pi, LASS data on K-pi elastic
scattering, and BES II data on J/Psi->K*(890)-K-pi.In all cases, the K-pi
S-wave is fitted well with a kappa resonance and Ko(1430); the kappa requires
an s-dependent width with an Adler zero near threshold. The pole position of
the kappa is at M - iGamma/2 = (750 +30 -55) - i(342 +- 60) MeV. The E791
collaboration fitted their data using a form factor for the production process
D->kappa-pi. It is shown that this form factor is not needed. The data require
point-like production with an RMS radius <0.38 fm with 95 percent confidence.Comment: 11 pages, 4 figures. Typos corrected. Material added to explain how a
pole is possible without the phase shift on the real s-axis going through 90
degree
QCD factorisation and flavour symmetries illustrated in B_d,s -> KK decays
We present a new analysis of B_d,s -> KK modes within the SM, relating them
in a controlled way through SU(3)-flavour symmetry and QCD-improved
factorisation. We propose a set of sum rules for B_d,s -> K^0 \bar K^0
observables. We determine B_s -> KK branching ratios and CP-asymmetries as
functions of A_dir(B_d -> K^0 \bar K^0), with a good agreement with current
experimental measurements of CDF. Finally, we predict the amount of U-spin
breaking between B_d -> pi+ pi- and B_s -> K+K-.Comment: 4 pages, 2 figures. Talk given at the 4th International Workshop on
the CKM Unitarity Triangle (CKM2006), 12-16 December 2006, Nagoya, Japan, to
appear in the proceedings (KEK Report
Nonleptonic charmless B_c decays and their search at LHCb
International audienceWe discuss the decay of B_c mesons into two light (pseudoscalar and vector) mesons. All these decay channels come from a single type of diagram, namely tree annihilation which allows us to derive simple relations among these processes. The size of annihilation contributions is an important issue in B physics, and we provide two different estimates in the case of non-leptonic charmless B_c decays, either a comparison with annihilation decays of heavy-light mesons or a perturbative model inspired by QCD factorisation. We finally discuss a possible search for these channels at LHCb
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