Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Search for the deeply bound $K^-pp$ state from the semi-inclusive
  forward-neutron spectrum in the in-flight $K^-$ reaction on helium-3   An experiment to search for the $K^-pp$ bound state was performed via the
in-flight $^3$He($K^-,n)$ reaction using 5.3 $\times$ $10^9$ kaons at 1 GeV/$c$
at the J-PARC hadron experimental facility. In the semi-inclusive neutron
missing-mass spectrum at $\theta_{n}^{lab}=0^\circ$, no significant peak was
observed in the region corresponding to $K^-pp$ binding energy larger than 80
MeV, where a bump structure has been reported in the $\Lambda p$ final state in
different reactions. Assuming the state to be isotropically decaying into
$\Lambda p$, mass-dependent upper limits on the production cross section were
determined to be 30--180, 70--250, and 100--270 $\mu$b/sr, for the natural
widths of 20, 60, and 100 MeV, respectively, at 95\% confidence level.

11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
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The categories of this paper are: comp-gas
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The categories of this paper are: solv-int
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The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
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The categories of this paper are: gr-qc
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The categories of this paper are: q-fin
10
The categories of this paper are: q-bio