Abstract
The NA60 experiment has studied low-mass muon pairs in 158 AGeV Indium-Indium collisions at the CERN SPS. A strong excess of pairs is observed above the expectation from neutral meson decays. The unprecedented sample size of 360 000 events and the good mass resolution of about 2% allow to isolate the excess by subtraction of the known sources. The shape of the resulting mass spectrum is consistent with a dominant contribution from π+ π- → ρ → μ+ μ- annihilation. The associated ρ spectral function shows a strong broadening, but essentially no shift in mass.
| Lingua originale | Inglese |
|---|---|
| pagine (da-a) | 715-718 |
| Numero di pagine | 4 |
| Rivista | Nuclear Physics A |
| Volume | 774 |
| Numero di pubblicazione | 1-4 |
| DOI | |
| Stato di pubblicazione | Pubblicato - 7 ago 2006 |
| Pubblicato esternamente | Sì |