8,595 research outputs found

### Charming penguin in nonleptonic B decays

In the study of two-body charmless B decays as a mean of looking for direct
CP-violation and measuring the CKM mixing parameters in the Standard Model, the
short-distance penguin contribution with its absorptive part generated by charm
quark loop seems capable of producing sufficient $B \to K\pi$ decays rates, as
obtained in factorization and QCD-improved factorization models. However there
are also long-distance charming penguin contributions which also give rise to a
strong phase due to the rescattering $D^{*}D^{*} \to K\pi$ . In this talk, I
would like to discuss \cite{Isola} a recent work on the long-distance charming
penguin as a a different approach to the calculation of the penguin
contributions in $B \to K\pi$ decays from charmed meson intermediate states.
Using chiral effective Lagrangian for light and heavy mesons, corrected for
hard pion and kaon momenta, we show that the charming-penguin contributions
increase significantly the $B \to K\pi$ decays rates from its short-distance
contributions, giving results in better agreement with experimental data.Comment: Talk given at the International Workshop on QCD: Theory and
Experiment, Martina Franca, Italy, 16--20 June 2001, LaTex, 9 page

### CP-violating asymmetry in $B^- \to \pi^+ \pi^- K^-$ and $B^- \rarr K^+ K^- K^-$ decays

The recent Belle and Babar measurements of the branching ratios $B^- \to
\pi^+ \pi^- K^-$ and $B^- \to K^+ K^- K^-$ and $B^\pm \to \chi_{c0} K^\pm$ have
renewed interests in these decays as another mean to look for direct CP
violation in B decays. In this talk, I would like to discuss a recent analysis
of the CP violating asymmetry in the partial widths for the decays $B^- \to
\pi^+ \pi^- K^-$ and $B^- \to K^+ K^- K^-$, which results from the interference
of the non resonant amplitude with the resonant amplitude $B^\pm \to \chi_{c0}
K^\pm$ $\rarr\pi^+ \pi^- K^\pm$ and $B^\pm \to \chi_{c0} K^\pm$ $\to K^+
K^- K^\pm$. For $\gamma \simeq 58^o$ we predict that the partial width
asymmetry could reach 10% for the $B^- \to \pi^+ \pi^- K^-$ decay and 16% for
the $B^- \to K^+ K^- K^-$decay.Comment: Talk given at the Quark Confinement and Hadron Spectrum V,
Gargnano,Italy,10-14 September 2002, LaTeX,4 page

### Power corrections in charmless B decays

Power corrections seem to play an important role in charmless B decays as
indicated by recent analysis using QCD Factorization. In this talk, I would
like to report on a recent work on power corrections in charmless B decays. By
using the ratio of the branching fraction of $B^+ \to \pi^+ K^{\ast 0}$ to that
of $B^0 \to \pi^- \rho^+$, for which the theoretical uncertainties are greatly
reduced, it is shown in a transparent manner that power corrections in
charmless B decays are probably large and that the $B^0 \to K^- \rho^+$ decay
could be explained with the annihilation term included. For ratios of direct CP
asymmetries, QCD Factorisation with the annihilation terms included would
predict the direct CP asymmetry of $B \to \pi^+ \pi^-$ to be about 3 times
larger than that of $B \to \pi^\pm K^\mp$, with opposite sign. In particular,
the large measured value for $B \to \pi^\pm K^\mp$ CP asymmetry implies
naturally a corresponding large $B \to \pi^+ \pi^-$ CP asymmetry as observed by
Belle. Experimentally any significant deviation from this prediction or
possibly the importance of long-distance rescattering effects.Comment: Talk given at the QCD Euroconference 2004, Montpellier 5-9 July
2004., LateX, 7 pages, 2 figure

### Relations for Direct CP asymmetries \\in $B\to \rm PP$ and $B\to \rm PV$ decays

The presence of additional strong phase from power corrections and other
chirally enhanced terms makes it more difficult to predict direct CP
asymmetries in two-body charmless B decays. In this talk, I would like to
report on a recent work on QCD Factorisation and Power Corrections in Charmless
B Decays. Using the measured branching ratios for $B\to \rm PV$, it is shown
that power corrections in charmless B decays are probably large, at least for
penguin dominated $\rm PV$ channels. Since the tree-penguin interference
responsible for direct CP asymmetries in two-body charmless B decays are
related by CKM factors and SU(3) symmetry, we find that, if power corrections
other than the chirally enhanced power corrections and annihilation topology
were negligible, QCD Factorisation would predict the direct CP asymmetry of $B
\to \pi^+ \pi^-$ to be about 3 times larger than that of $B \to \pi^\pm K^\mp$,
with opposite sign, in agreement with the latest measurement from Belle.
Similar relations are also given for direct CP asymmetries in $B\to\rm PV$ .Comment: Talk given at the QCD@Work 2005, Conversano, Bari, Italy, 16-20 June
2005, LateX, 7 pages, 2 figures, to appear in the Proceeding

### Non factorizable Effetcs in $B \to \chi_{c0} K^-$ from Charmed Meson Rescattering

The $B^{-} \to \chi_{c0} K^{-}$ decay which has no visible factorizable
amplitude, could be induced by the Cabibbo-allowed, color-favored $B^{-} \to
D_{s}D^{*0}$, $B^{-} \to D^{*0}_{s}D^{0}$ and $B \to D_{s}^{*}D^{*}$ via the
rescattering of these charmed mesons to $\chi_{co} K^{-}$. In this talk I would
like to discuss a recent calculation \cite{Colangelo} of these effects for
$B^{-} \to \chi_{c0} K^{-}$ and $B^{-} \to J/\psi K^{-}$ decays. We find that
charmed scattering effects seem capable of producing a large $B^{-} \to
\chi_{c0} K^{-}$ branching ratio measured by the Babar and Belle Collaboration
and make a significant contribution to the $B^{-} \to J/\psi K^{-}$ branching
ratios in agreement with experiments.Comment: Talk at the International Workshop on QCD: QCD@Work 2003 - Conversano
(Italy) 14-18 June 2003 (eConf C030614), 4 pages LaTeX, 3 eps figures,
revised version, 1 reference added, text unchange

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