Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Extraction of $ND$ scattering lengths from the
  $\Lambda_b\rightarrow\pi^-pD^0$ decay and properties of the
  $\Sigma_c(2800)^+$   The isovector and isoscalar $ND$ $s$-wave scattering lengths are extracted by
fitting to the LHCb data of the $pD^0$ invariant-mass distribution in the decay
$\Lambda_b\rightarrow\pi^-pD^0$, making use of the cusp effect at the $nD^+$
threshold. The analysis is based on a coupled-channel nonrelativistic effective
field theory. We find that the real part of the isovector $ND$ scattering
length is unnaturally large due to the existence of a near-threshold state with
a mass around 2.8 GeV. The state is consistent with the $\Sigma_c(2800)^+$
resonance observed at Belle. Our results suggest that it couples strongly to
the $ND$ channel in an $s$-wave, and that its quantum numbers are $J^P=1/2^-$.
The strong cusp behavior at the $nD^+$ threshold can be verified using updated
LHCb data.

23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph