Levi Sandri, P.
Proton-Proton Scattering
SIG/SIG
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A Study of the centrally produced pi+ pi- pi0 channel in p p interactions at 450-GeV/c

The WA102 collaboration Barberis, D. ; Beusch, W. ; Binon, F.G. ; et al.
Phys.Lett.B 422 (1998) 399-404, 1998.
Inspire Record 466032 DOI 10.17182/hepdata.41629

The reaction pp -> pf (pi+pi-pi0) ps has been studied at 450 GeV/c in an experiment designed to search for gluonic states. A spin analysis has been performed and the dPT filter applied. The analysis confirms the previous observation that all undisputed qqbar states are suppressed at small dPT. In addition, a clear difference is observed in the production mechanism for the eta and omega.

1 data table
Table 1

SIG(C=TOT) denotes the total cross section for each resonance. The variable ABS(PT(P=3)-PT(P=4)) is used as a glueball-QUARK QUARKBAR filter (see F.E.Close and A.Krik, PL 397B, 333 (1997)).


Production of Phi and omega mesons in near-threshold p p reactions.

The DISTO collaboration Balestra, F. ; Bedfer, Y. ; Bertini, R. ; et al.
Phys.Rev.Lett. 81 (1998) 4572-4575, 1998.
Inspire Record 481641 DOI 10.17182/hepdata.19496

The ratio of the exclusive production cross sections for φ and ω mesons has been measured in pp reactions at Tbeam=2.85GeV. The observed φ/ω ratio is (3.7±0.7−0.9+1.2)×10−3. After phase space corrections, this ratio is about a factor of 10 enhanced relative to naive predictions based upon the Okubo-Zweig-Iizuka rule, in comparison to an enhancement by a factor of ∼3 previously observed at higher energies. The modest increase of this enhancement near the production threshold is compared to the much larger increase of the φ/ω ratio observed in specific channels of p¯p annihilation experiments.

1 data table
Table 1

No description provided.


Anomalous J / psi suppression in Pb - Pb interactions at 158 GeV/c per nucleon

The NA50 collaboration Abreu, M.C. ; Alessandro, B. ; Alexa, C. ; et al.
Phys.Lett.B 410 (1997) 337-343, 1997.
Inspire Record 459314 DOI 10.17182/hepdata.28260

The Drell-Yan and J ψ cross-sections measured in PbPb collisions are compared with the values extrapolated from the results obtained in proton and light ion induced reactions. While the Drell-Yan production exhibits the normal expected behaviour, the yield of J ψ in PbPb interactions is abnormally low, as it lies 9 standard deviations below the expected value. Moreover, the departure from the expected behaviour increases significantly from peripheral to central collisions.

2 data tables
Table 1

The results from other experiments are also presented.

Table 2

Different data are rescaled at 200 GeV.


High Statistics Study of ($\sim$ 10$^6$ events) of $J/\psi$ Production and $\Upsilon$ Production in the energy range 150 to 280 GeV by $\pi^\pm$, $p^\pm$ incident particle

The Saclay-CERN-College de France-Ecole Poly-Orsay collaboration Badier, J. ; Boucrot, J. ; Bourotte, J. ; et al.
AIP Conf.Proc. 68 (1981) 201-204, 1981.
Inspire Record 154782 DOI 10.17182/hepdata.49656

We have performed in the NA3 experiment the study of high mass dimuon production by a hadronic unseparated beam on hydrogen and platinum targets. The comparison of the production cross‐section for proton and antiproton together with the differential cross‐section dσ/dx allows us to compare the data with a production mechanism involving quark‐antiquark and gluon‐gluon interactions. The cosΘ* distribution of the same J/ψ data have also been analysed and results will be presented. Finally we have observed T production from 150 GeV/c incident pions.

4 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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