Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quark model: recent issues   In the first part I briefly survey recent issues in constituent quark models
raised by the observation of unusual hadronic states. In particular I discuss
the role of higher Fock components in the wave function of baryons and the
possible interpretation of open charm and of new charmonium-type resonances as
tetraquarks. In the second part I show support for the quark model dynamics
obtained in a model independent way from the $1/N_c$ expansion approach of QCD
which proved to be successful in describing baryon properties.

17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph