Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The transverse structure of the QCD string   The characterization of the transverse structure of the QCD string is
discussed. We formulate a conjecture as to how the stress-energy tensor of the
underlying gauge theory couples to the string degrees of freedom. A consequence
of the conjecture is that the energy density and the longitudinal-stress
operators measure the distribution of the transverse position of the string, to
leading order in the string fluctuations, whereas the transverse-stress
operator does not. We interpret recent numerical measurements of the transverse
size of the confining string and show that the difference of the energy and
longitudinal-stress operators is the appropriate probe to use when comparing
with the next-to-leading order string prediction. Secondly we derive the
constraints imposed by open-closed string duality on the transverse structure
of the string. We show that a total of three independent `gravitational' form
factors characterize the transverse profile of the closed string, and obtain
the interpretation of recent effective string theory calculations: the square
radius of a closed string of length \beta, defined from the slope of its
gravitational form factor, is given by (d-1)/(2\pi\sigma)\log(\beta/(4r_0)) in
d space dimensions. This is to be compared with the well-known result that the
width of the open-string at mid-point grows as (d-1)/(2\pi\sigma) log(r/r_0).
We also obtain predictions for transition form factors among closed-string
states.

13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
28
The categories of this paper are: alg-geom