학술논문
Experimental signature of in-medium mass modification of vector mesons at normal nuclear density
Document Type
Article
Author
Muto, R; Chiba, J; En'yo, H; Fukao, Y; Funahashi, H; Hamagaki, H; Ieiri, M; Ishino, M; Kanda, H; Kitaguchi, M; Mihara, S; Miwa, K; Miyashita, T; Murakami, T; Nakura, T; Naruki, M; Nomachi, M; Ozawa, K; Sakuma, F; Sasaki, O; Sato, H D; Sekimoto, M; Tabaru, T; Tanaka, K H; Togawa, M; Yamada, S; Yokkaichi, S; Yoshimura, Y
Source
Journal of Physics G: Nuclear and Particle Physics; August 1, 2004, Vol. 30 Issue: 8 pS1023-S1026, 4p
Subject
Language
ISSN
09543899; 13616471
Abstract
We measured invariant mass spectra of e+e− pairs produced in 12 GeV p + A interaction to investigate in-medium mass modification of vector mesons. We observed an enhancement over the known hadronic sources on the low-mass side of the ω meson mass peak. The obtained ρ/ω ratio indicates that this enhancement mainly results from ρ mesons whose mass was modified in nuclear matter. We performed a toy model calculation based on the prediction using the QCD sum rule. It reproduced well the tendency of our data.