Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Medium effects in the production and decay of vector mesons in
  pion-nucleus reactions   The $\omega$-, $\rho$- and $\phi$-resonance production and their dileptonic
decay in $\pi^- A$ reactions at 1.1 - 1.7 GeV/c are calculated within the
intranuclear cascade (INC) approach. The invariant mass distribution of the
dilepton pair for each resonance can be decomposed in two components which
correspond to their decay 'inside' the target nucleus and in the vacuum,
respectively. The first components are strongly distorted by the nuclear medium
due to resonance-nucleon scattering and a possible mass shift at finite baryon
density. These medium modifications are compared to background sources in the
dilepton spectrum from $\pi N$ bremsstrahlung as well as the Dalitz decays of
$\omega$ and $\eta$ mesons produced in the reaction. Detailed predictions for
$\pi^- Pb$ reactions at 1.3 and 1.7 GeV/c are made within several momentum bins
for the lepton pair.

7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con