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Negative Hyperon Production in High-Energy Proton Interactions

Hungerbuhler, V. ; Majka, R. ; Marx, J.N. ; et al.

Phys.Rev.D 12 (1975) 1203-1210, 1975.

Inspire Record 104138 DOI 10.17182/hepdata.4668

Momentum spectra for forward Σ− and Ξ− production by protons on beryllium are presented. Σ− production data for two primary proton momenta are compared to test scaling of the invariant cross section. In addition, the observed single-particle momentum distributions are compared with single-particle spectra from other inclusive reactions initiated by protons.

6 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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The energy dependence of the pp->K+ n Sigma+ reaction close to threshold

Valdau, Yu. ; Barsov, S. ; Buscher, M. ; et al.

Phys.Rev.C 81 (2010) 045208, 2010.

Inspire Record 846092 DOI 10.17182/hepdata.55315

The production of the Sigma+ hyperon through the pp->K+nSigma+ reaction has been investigated at four energies close to threshold, 1.826, 1.920, 1.958, and 2.020 GeV. At low energies, correlated K+pi+ pairs can only originate from Sigma+ production so that their measurement allows the total cross section for the reaction to be determined. The results obtained are completely consistent with the values extracted from the study of the K+-proton correlation spectra obtained in the same experiment. These spectra, as well as the inclusive K+ momentum distributions, also provide conservative upper limits on the Sigma+ production rates. The measurements show a Sigma+ production cross section that varies roughly like phase space and, in particular, none of the three experimental approaches used supports the anomalously high near-threshold pp->K+ nSigma+ total cross section previously reported [T. Rozek et al., Phys. Lett. B 643, 251 (2006)].

6 data tables

Table 1

The K+ double-differential cross section at each of the 5 beam energies intgerated over momentum bins of width +- 12 MeV/c. Note the errors do not include the 7 PCT systematic uncertainty coming from the normalization.

Table 2

Total cross section for the P P --> K+ P LAMBDA.

Table 3

Total cross section for the P P --> K+ P SIGMA0.

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The p p --> K+ n Sigma+ reaction near threshold.

Valdau, Yu. ; Koptev, V. ; Barsov, S. ; et al.

Phys.Lett.B 652 (2007) 245-249, 2007.

Inspire Record 747303 DOI 10.17182/hepdata.31457

Inclusive K+ production in proton-proton collisions has been measured at a beam energy of 2.16 GeV using the COSY-ANKE magnetic spectrometer. The resulting spectrum, as well as those corresponding to K+ p and K+ pi+ correlated pairs, can all be well described using consistent values of the total cross sections for the pp->K+ p Lambda, pp->K+ p Sigma0, and pp->K+ n Sigma+ reactions. While the resulting values for Lambda and Sigma0 production are in good agreement with world data, our value for the total Sigma+ production cross section, sigma(pp->K+ n Sigma+) = 2.5+/-0.6(stat)+/-0.4(syst) mkb at an excess energy of epsilon=129 MeV, could only be reconciled with other recently published data if there were a highly unusual near--threshold behaviour.

4 data tables

Table 1

Total cross section for the reaction P P --> K+ N SIGMA+.

Table 2

Total cross section for the reaction P P --> K+ P LAMBDA.

Table 3

Total cross section for the reaction P P --> K+ P SIGMA0.

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Measurement of differential cross sections for processes $\gamma d\to p n$, $\pi^0 d$, and $p X$ in the energy range of dibaryon resonances

Baba, K. ; Endo, I. ; Fukuma, H. ; et al.

Phys.Rev.C 28 (1983) 286-293, 1983.

Inspire Record 195610 DOI 10.17182/hepdata.26333

The differential cross section for the reactions γd→pn, γd→π0d, and γd→pX has been measured by using a tagged photon beam in the energy range of dibaryon resonances. The most characteristic feature of the data for γd→pn is a forward nonpeaking angular distribution. This behavior is in complete disagreement with the existing predictions which take into account the dibaryon resonances. A phenomenological analysis is made by slightly modifying the model of the Tokyo group, but no satisfactory result is obtained. The data for γd→π0d at large angles show that the differential cross section decreases exponentially as a function of pion angle. A comparison is made with a Glauber model calculation. The result seems to be rather in favor of the existence of dibaryon resonances, but a clear conclusion is not possible because of a lack of more accurate data. In the process γd→pX, a broad peak due to quasifree pion production is observed, but the limitation of experimental sensitivity does not allow us to have a definite conclusion for the dibaryon resonance of mass 2.23 GeV conjectured by the Saclay group.

6 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

FOR ANGLES >16 DEG THE OVERALL UNCERTAINTY IN ABSOLUTE NORMALIZATION IS ABOUT 10%.