Low mass dimuon production in proton and ion induced interactions at the SPS

Citation
Mc. Abreu et al., Low mass dimuon production in proton and ion induced interactions at the SPS, EUR PHY J C, 13(1), 2000, pp. 69-78
Citations number
41
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
EUROPEAN PHYSICAL JOURNAL C
ISSN journal
1434-6044 → ACNP
Volume
13
Issue
1
Year of publication
2000
Pages
69 - 78
Database
ISI
SICI code
1434-6044(200003)13:1<69:LMDPIP>2.0.ZU;2-0
Abstract
The low mass dimuon spectra collected in p-U collisions by the NA38 experim ent significantly exceeds the total cross section expected from previous an alysis, done by other experiments. The 'excess' events have a harder p(T) d istribution than the muon pairs from eta and omega Dalitz decays, expected to dominate the mass window 0.4-0.65 GeV/c(2). We conjecture that the exces s events may be due to q (q) over bar annihilations, negligible at low p(T) but made visible by the m(T) cut applied in the NA38 data. Taking this ass umption to parametrise the p-U spectra, we proceed with the corresponding a nalysis of the S-Cu, S-U and Pb-Pb data, collected by the NA38 and NA50 exp eriments, comparing the measured low mass dimuon spectra with the 'expected cocktail'.