Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measurement of $\mathcal{R}(D)$ and $\mathcal{R}(D^*)$ with a
  semileptonic tagging method   We report a measurement of the ratios of branching fractions
$\mathcal{R}(D^{(*)}) = {\cal B}(\bar{B} \to D^{(*)} \tau^-
\bar{\nu}_{\tau})/{\cal B}(\bar{B} \to D^{(*)} \ell^- \bar{\nu}_{\ell})$ where
$\ell$ denotes an electron or a muon. The results are based on a data sample
containing $772 \times 10^6$ $B\bar{B}$ events recorded at the $\Upsilon(4S)$
resonance with the Belle detector at the KEKB $e^+ e^-$ collider. The tag-side
B meson is reconstructed in a semileptonic decay mode, and the signal-side
${\tau}$ is reconstructed in a purely leptonic decay. The results are
$\mathcal{R}(D) = 0.307 \pm 0.037 \pm 0.016$ and $\mathcal{R}(D^*)=0.283 \pm
0.018 \pm 0.014$, where the first uncertainties are statistical and the second
are systematic. These results are in agreement with the Standard Model
predictions within 0.2 and 1.1 standard deviations, respectively.

34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
2
The categories of this paper are: math
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
18
The categories of this paper are: econ