Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Third Family Hypercharge Model for $R_{K^{(\ast)}}$ and Aspects of the
  Fermion Mass Problem   We present a model to explain LHCb's recent measurements of $R_K$ and
$R_{K^{\ast}}$ based on an anomaly-free, spontaneously-broken $U(1)_F$ gauge
symmetry, without any fermionic fields beyond those of the Standard Model (SM).
The model explains the hierarchical heaviness of the third family and the
smallness of quark mixing. The $U(1)_F$ charges of the third family of SM
fields and the Higgs doublet are set equal to their respective hypercharges. A
heavy $Z^\prime$ particle with flavour-dependent couplings can modify the
$[\overline{b_L} \gamma^\rho s_L][\overline{\mu_L} \gamma_\rho \mu_L]$
effective vertex in the desired way. The $Z^\prime$ contribution to
$B_s-\overline{B_s}$ mixing is suppressed by a small mixing angle connected to
$V_{ts}$, making the constraint coming from its measurement easier to satisfy.
The model can explain $R_K$ and $R_{K^{(\ast)}}$ whilst simultaneously passing
other constraints, including measurements of the lepton flavour universality of
$Z$ couplings.

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The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
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The categories of this paper are: comp-gas
24
The categories of this paper are: dg-ga
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The categories of this paper are: funct-an
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The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph