φ and ω − ρ production in d–C, d–U, S–U and Pb–Pb at SPS energies

Abstract

Nuclear dependence of ϕ and ω − ρ production is studied from heavy nuclei and deuteron-induced reactions. In addition to the ratio ϕ/(ω + ρ), closely related to the strangeness saturation factor γS in transverse mass (MT) domains, absolute cross-sections and multiplicities are also presented. The ϕ multiplicities for central Pb–Pb collisions, as obtained in the most recent NA50 measurement, lead to an updated version of the ϕ puzzle, where reduced discrepancy between experiments opens a new space for a systematic difference between the leptonic and hadronic decay channels.

φ production in In–In collisions at 158 A GeV

“…The absolute yields, however, disagree by a factor ∼4 in full phase space [22]. A recent NA50 analysis of a new sample confirmed previous findings [23]. The NA49 and NA50 results disagree also on the T eff parameters extracted from the transverse mass spectra fitted with the thermal ansatz.…”

$ϕ$ Production in In-In Collisions at 158 AGeV

“…The absolute yields, however, disagree by a factor ∼ 4 in full phase space [22]. A recent NA50 analysis of a new sample confirmed previous findings [23]. The NA49 and NA50 results disagree also on the T ef f parameters extracted from the transverse mass spectra fitted with the thermal ansatz.…”

A comparative measurement of ϕ→K+K− and ϕ→μ+μ−Arnaldi1, Castor2, Chaurand3 et al. 2011Physics Letters B8140View full textAdd to dashboardCite

“…250 ± 4 1.03 ± 0.03 ± 0.07 253 ± 11 ± 5 1.01 ± 0.07 ± 0.05 3.5 ± 0.2 ± 0.2 177 249 ± 5 1.65 ± 0.06 ± 0.07 254 ± 13 ± 6 1.49 ± 0.11 ± 0.07 4.6 ± 0.3 ± 0.4 tios for the decay into kaon and lepton pairs may be modified in the medium [2,3]. φ meson production was first studied at the CERN SPS by the NA49 [4,5] and NA50 [6,7] experiments. NA49 detected the φ through its decay into K + K − pairs, while NA50 studied the φ → µ + µ − channel.…”