Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonfactorizable Effects in Exclusive Charmless B Decays   Nonfactorizable effects in charmless $B\to PP, VP$ decays can be lumped into
the effective parameters a_i that are linear combinations of Wilson
coefficients, or equivalently absorbed into the effective number of colors N_c.
Naive factorization with N_c=3 fails to explain the CLEO data of $B^\pm \to
\omega K^\pm$, showing the first evidence for the importance of nonfactorizable
contributions to the penguin amplitude. The decays $B^\pm \to \omega\pi^\pm$
dominated by tree amplitudes are sensitive to the interference between external
and internal W-emission diagrams. Destructive interference implied by
$N_c=\infty$ leads to a prediction of ${\cal B}(B^\pm \to \omega \pi^\pm)$
which is about $2\sigma$ too small compared to experiment. Therefore, the CLEO
data of $B^\pm \to \omega K^\pm, \omega\pi^\pm$ suffice to rule out N_c=3 and
strongly disfavor $N_c=\infty$ for rare charmless B decays. Factorization based
on $N_c\approx 2$ can accommodate the data of $B^\pm \to \omega K^\pm$, but it
predicts a slightly smaller branching ratio of $B^\pm \to \omega\pi^\pm$ with
${\cal B}(B^\pm \to \omega\pi^\pm)/{\cal B} (B^\pm \to \omega K^\pm)=0.6$. We
briefly explain why the 1/N_c expansion is still applicable to the B meson
decay once the correct large-N_c counting rule for the Wilson coefficient
c_2(m_b) is applied.

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The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
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The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
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The categories of this paper are: plasm-ph
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
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The categories of this paper are: stat
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The categories of this paper are: econ
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
19
The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
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The categories of this paper are: cs