@article{3053191,
    title = "Excess of continuum dimuon production at masses between threshold and
the J/Psi in S-W interactions at 200 GeV/c/nucleon",
    author = "Angelis, ALS and Antos, J and Beaulieu, M and Beker, H and Bystricky, J and and Catanesi, MG and Cerello, P and Dagan, S and Dellacasa, G and Di and Liberto, S and Dolgoshein, B and Esten, M and Fabjan, CW and Gaidot, A and and Gallio, M and Giubellino, P and Goerlach, U and Guerra, C and Hamel, and LA and Konovalov, S and Kralik, I and London, G and Martelli, F and and Martin, JP and Masera, M and Mazzoni, MA and Meddi, F and Muciaccia, MT and and Muraviev, S and Nomerotsky, A and Oren, Y and Pansart, JP and and Poulard, G and Ramello, L and Riccati, L and Rosa, G and Sandor, L and and Sarris, M and Scomparin, E and Shmeleva, A and Simone, S and Smirnov, S and and Taras, P and Urban, J and Vercellin, E and HELIOS 3 Collaboration",
    journal = "The European Physical Journal C - Particles and Fields",
    year = "2000",
    volume = "13",
    number = "3",
    pages = "433-452",
    publisher = "Springer-Verlag",
    issn = "1434-6044, 1434-6052",
    doi = "10.1007/s100520000314",
    abstract = "Results are presented on dimuon production for invariant masses ranging
from the dimuon threshold up to the J/Psi meson. Proton-tungsten and
sulphur-tungsten interactions at 200 GeV/c/nucleon were measured over a
large kinematic region, using the HELIOS/3 dimuon spectrometer at the
CERN SPS. In the continuum regions between the dimuon threshold and the
rho/omega mesons, and between the phi and J/Psi mesons, an excess is
observed in S-W interactions relative to minimum bias p-W interactions.
The observed excess is continuous over the explored mass range and has
no apparent resonant structure. In the low mass region the dimuon yield
increases by (76 +/- 4)% of the corresponding p-W dimuon spectrum,
whereas in the higher mass region the excess amounts to 2.4 +/- 0.3
times the p-W yield. The observed excess for the low mass region follows
an exponential transverse mass distribution with an average inverse
slope parameter T of (190 +/- 5) MeV/c(2), constant for all but the
lowest charged multiplicity interval and consistent with the slope of
the excess in the higher mass region. In the invariant mass range of
1.35-2.5 GeV/c(2) the continuum dimuon mass distribution observed in p-W
interactions can be quantitatively understood as a sum of three expected
contributions (vector meson decays, semileptonic charm decays and
Drell-Yan process), but both in central and in minimum bias S-W
interactions an excess is observed with respect to these sources which
does not depend on centrality, nor very strongly on the transverse
momentum."
}