Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Long-distance weak annihilation contribution to the $B^{\pm}\to
  (\pi^{\pm},K^{\pm}) \ell^+\ell^-$ decays   We propose an alternative evaluation of the long-distance weak annihilation
(WA, also called one-photon exchange in this paper) contribution to the rare
semileptonic $B^{\pm}\to (\pi^{\pm},K^{\pm})\ell^+\ell^-$ ($\ell=e,\,\mu$)
decays. This hadronic description at low energies is matched at intermediate
energies to its short-distance counterpart in terms of quark and gluon degrees
of freedom.
  Although the WA contribution does not contribute to solve the possible
breaking of lepton-universality observed by LHCb in the $B^{\pm}\to
K^{\pm}(\mu^+\mu^-/e^+e^-)$ ratio, nor provides an important hadronic
contamination to their decay rates, its contribution to the branching ratios
(and direct CP asymmetry) of the $B^{\pm}\to \pi^{\pm}\ell^+\ell^-$ transitions
turns out to be significant. This hadronic pollution should be taken into
account when looking for new physics effects in decays into pions, which
suggests to restrict these searches to squared lepton-pair invariant mass in
the $(1,8)$ GeV$^2$ range. The interference of the one-photon exchange
contribution with the dominant short-distance one-loop amplitude induces a
sizable CP asymmetry in these rare decays, which calls for dedicated
measurements.

26
The categories of this paper are: bayes-an
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
32
The categories of this paper are: atom-ph