Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Vacuum structure of a modified MIT Bag   An alternative to introducing and subsequently renormalizing classical
parameters in the expression for the vacuum energy of the MIT bag for quarks is
proposed in the massless case by appealing to the QCD trace anomaly and scale
separation due to asymptotic freedom. The explicit inclusion of gluons implies
an unrealistically low separation scale.

9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc