The experiment E325 has been performed at KEK PS. The data taking has been completed on February 2002. We have measured the invariant mass spectrum of e+e-pairs based on the statistics 100 times larger than our previous publication. On the low-mass side of ρ/ω meson, an enhancement over the known hadronic sources has been observed. The obtained ρ/ω ratio in the spectrum is smaller than the ratio in pp interaction. This suggests that ρ meson mass has been modified in nuclear matter.
ASJC Scopus subject areas
- Nuclear and High Energy Physics