Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Recent measurements of branching fractions and $CP$ asymmetries of
  charmless hadronic $B$ meson decays at Belle   Hadronic $B$ decays without a charm quark constitute a powerful probe to
search for physics beyond the standard model as well as to provide constraints
on $CP$ violation parameters. We report final measurements from Belle of the
branching fractions and $CP$ asymmetries for the decays $B^{0} \rightarrow
\pi^{0} \pi^{0}$ and $B^{\pm} \rightarrow K^{+} K^{-} \pi^{\pm}$. The $B^{0}
\rightarrow \pi^{0} \pi^{0}$ measurements enable us to improve constraints on
the angle $\phi_{2}$ of the CKM unitarity triangle. For $B^{\pm} \rightarrow
K^{+} K^{-} \pi^{\pm}$ we measure $CP$ asymmetry as a function of the invariant
mass of the $K^{+}K^{-}$ system, where we find a strong evidence for large $CP$
violation and a large increase in yield at low mass region. This result
challenges conventional theoretical approaches as it requires a large
enhancement in both tree and loop level diagrams in the same small region of
phase-space.

12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th