Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Mixing angle of $K_1$ axial vector mesons   Analyses of various experimental measurements all indicate that the mixing
angle $\theta_{K_1}$ of $K_1(1270)$ and $K_1(1400)$ is in the vicinity of
$33^\circ$ or $57^\circ$. However, whether $\theta_{K_1}$ is greater or less
than $45^\circ$ is still quite controversial. For example, there were two very
recent studies of the strong decays of $K_1$ mesons. One group claimed that
$\theta_{K_1}\approx 60^\circ$, while the other group obtained
$\theta_{K_1}=(33.6\pm4.3)^\circ$. Since the determination of the mixing angles
$\alpha_{^3\!P_1}$ and $\alpha_{^1\!P_1}$ with the former (latter) being the
mixing angle of $f_1(1285)$ ($h_1(1170)$) and $f_1(1420)$ ($h_1(1380)$) in the
flavor basis through mass relations depend on $\theta_{K_1}$, we show that
$\theta_{K_1}\approx 57^\circ$ is ruled out as it leads to a too large
deviation from ideal mixing in the $^1\!P_1$ sector, inconsistent with the
lattice calculation of $\alpha_{^1\!P_1}$ and the observation of strong decays
of $h_1(1170)$ and $h_1(1380)$. We find that for $\theta_{K_1}\approx
(28-30)^\circ$, the corresponding $\alpha_{^3\!P_1}$ and $\alpha_{^1\!P_1}$
agree well with all lattice and phenomenological analyses. This again
reinforces the statement that $\theta_{K_1}\sim 33^\circ$ is much more favored
than $57^\circ$.

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The categories of this paper are: q-alg
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The categories of this paper are: ao-sci
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The categories of this paper are: adap-org
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The categories of this paper are: chao-dyn
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The categories of this paper are: supr-con
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The categories of this paper are: quant-ph
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The categories of this paper are: cond-mat
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The categories of this paper are: patt-sol
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The categories of this paper are: eess
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The categories of this paper are: q-fin
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The categories of this paper are: physics
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The categories of this paper are: q-bio
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The categories of this paper are: solv-int
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The categories of this paper are: math
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The categories of this paper are: stat
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The categories of this paper are: gr-qc