Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Light-meson masses in an unquenched quark model   We perform a coupled-channels calculation of the masses of light mesons with
the quantum numbers $IJ^{P=-}$, $(I,J)=0,1$, by including $q\bar{q}$ and
$(q\bar{q})^2$ components in a nonrelativistic chiral quark model. The coupling
between two- and four-quark configurations is realized through a $^3P_0$
quark-pair creation model. With the usual form of this operator, the mass
shifts are large and negative, an outcome which raises serious issues of
validity for the quenched quark model. Herein, therefore, we introduce some
improvements of the $^3P_0$ operator in order to reduce the size of the mass
shifts. By introducing two simple factors, physically well motivated, the
coupling between $q\bar{q}$ and $(q\bar{q})^2$ components is weakened,
producing mass shifts that are around 10-20% of hadron bare masses.

1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph