Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quark Masses and Chiral Symmetry   I discuss the global structure of the strongly interacting gauge theory of
quarks and gluons as a function of the quark masses and the CP violating
parameter $\theta$. I concentrate on whether a first order phase transition
occurs at $\theta=\pi.$ I show why this is expected when multiple flavors have
a small degenerate mass. This transition can be removed by sufficient
flavor-breaking. I speculate on the implications of this structure for Wilson's
lattice fermions.

18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
13
The categories of this paper are: quant-ph