First measurement of the rho spectral function in high-energy nuclear collisions.
Phys Rev Lett
; 96(16): 162302, 2006 Apr 28.
Article
em En
| MEDLINE
| ID: mdl-16712218
We report on a precision measurement of low-mass muon pairs in 158 AGeV indium-indium collisions at the CERN SPS. A significant excess of pairs is observed above the yield expected from neutral meson decays. The unprecedented sample size of 360,000 dimuons and the good mass resolution of about 2% allow us to isolate the excess by subtraction of the decay sources. The shape of the resulting mass spectrum is consistent with a dominant contribution from pi+pi- -->rho -->mu+mu- annihilation. The associated space-time averaged spectral function shows a strong broadening, but essentially no shift in mass. This may rule out theoretical models linking hadron masses directly to the chiral condensate.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Phys Rev Lett
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Itália