Observation of rho/omega meson modification in nuclear matter.
/ Authors
K. Ozawa, H. En’yo, H. Funahashi, M. Kitaguchi, M. Ishino, H. Kanda, S. Mihara, T. Miyashita, T. Murakami, R. Muto
and 14 more authors
M. Naruki, F. Sakuma, H. Sato, T. Tabaru, S. Yamada, S. Yokkaichi, Y. Yoshimura, J. Chiba, M. Ieiri, M. Nomachi, O. Sasaki, M. Sekimoto, K. Tanaka, H. Hamagaki
/ Abstract
We measured the invariant mass spectra of electron-positron pairs in the target rapidity region of 12-GeV p+A reactions. We have observed a significant difference in the mass spectra below the omega meson between p+C and p+Cu interactions. This difference indicates that the spectral shape of mesons is modified at normal nuclear-matter density.
Journal: Physical review letters