Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Collective mechanism of dilepton production in high-energy nuclear
  collisions   Collective bremsstrahlung of vector meson fields in relativistic nuclear
collisions is studied within the time-dependent Walecka model. Mutual
deceleration of the colliding nuclei is described by introducing the effective
stopping time and average rapidity loss of baryons. It is shown that
electromagnetic decays of virtual omega-mesons produced by bremsstrahlung
mechanism can provide a substantial contribution to the soft dilepton yield at
the SPS bombarding energies. In particular, it may be responsible for the
dilepton enhancement observed in 160 AGev central Pb+Au collisions. Suggestions
for future experiments to estimate the relative contribution of the collective
mechanism are given.

16
The categories of this paper are: stat
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex