HEPData Search

The exclusive production cross sections for $\omega$ and $\phi$ mesons have been measured in proton-proton reactions at $p_{lab}=3.67$ GeV/c. The observed $\phi/\omega$ cross section ratio is $(3.8\pm0.2^{+1.2}_{-0.9})\times 10^{-3}$. After phase space corrections, this ratio is enhanced by about an order of magnitude relative to naive predictions based upon the Okubo-Zweig-Iizuka (OZI) rule, in comparison to an enhancement by a factor $\sim 3$ previously observed at higher beam momenta. The modest increase of this enhancement near the production threshold is compared to the much larger increase of the $\phi/\omega$ ratio observed in specific channels of $\bar pp$ annihilation experiments. Furthermore, differential cross section results are also presented which indicate that although the $\phi$ meson is predominantly produced from a $^3P_1$ proton-proton entrance channel, other partial waves contribute significantly to the production mechanism at this beam momentum.

8 data tables

Table 1

No description provided.

Table 2

Differential cross section of OMEGA production.

Table 3

Differential cross section of PHI production.

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Production of eta' mesons in the p p --> p p eta' reaction at 3.67-GeV/c.

The DISTO collaboration Balestra, F. ; Bedfer, Y. ; Bertini, R. ; et al.

Phys.Lett.B 491 (2000) 29-35, 2000.

Inspire Record 532685 DOI 10.17182/hepdata.31445

The ratio of the total exclusive production cross sections for $\eta\prime$ and $\eta$ mesons has been measured in the $pp$ reaction at $p_{beam}=3.67$ GeV/c. The observed $\eta\prime/\eta$ ratio is $(0.83\pm{0.11}^{+0.23}_{-0.18})\times 10^{-2}$ from which the exclusive $\eta\prime$ meson production cross section is determined to be $(1.12\pm{0.15}^{+0.42}_{-0.31})\mu b$. Differential cross section distributions have been measured. Their shape is consistent with isotropic $\eta\prime$ meson production.

5 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

Only statistial errors.

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Anti-proton He-4 interactions at 200-MeV/c

Balestra, F. ; Batusov, Yu.A. ; Bendiscioli, G. ; et al.

Phys.Lett.B 305 (1993) 18-22, 1993.

Inspire Record 362745 DOI 10.17182/hepdata.28940

The differential cross sections for antiproton elastic scattering on 4 He at 192.8 MeV/ c are measured. The annihilation cross section σ a = (377.6 ± 8.0) mb, the elastic cross section σ el = (206.3 ± 6.6) mb and the total p 4 He interaction cross section σ tot = (583.9 ± 10.4) mb are determined. The ratio of the real to imaginary part of the forward p 4 He amplitude is found: π =−0.17± 0.33 0.24 . Partial wave analysis reveals that the S, P and D waves are essential in this energy region.

7 data tables

Table 1

Charged prong multiplicity distributions in pbar HE annihilation.

Table 2

Mean charged particle multiplicity in pbar HE4 annihilations.

Table 3

No description provided.