Separated structure functions for the exclusive electroproduction of K+ Lambda and K+ Sigma0 final states.

The CLAS collaboration Ambrozewicz, P. ; Carman, D.S. ; Feuerbach, R.J. ; et al.
Phys.Rev.C 75 (2007) 045203, 2007.
Inspire Record 732363 DOI 10.17182/hepdata.4994

We report measurements of the exclusive electroproduction of $K^+\Lambda$ and $K^+\Sigma^0$ final states from a proton target using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The separated structure functions $\sigma_T$, $\sigma_L$, $\sigma_{TT}$, and $\sigma_{LT}$ were extracted from the $\Phi$- and $\epsilon$-dependent differential cross sections taken with electron beam energies of 2.567, 4.056, and 4.247 GeV. This analysis represents the first $\sigma_L/\sigma_T$ separation with the CLAS detector, and the first measurement of the kaon electroproduction structure functions away from parallel kinematics. The data span a broad range of momentum transfers from $0.5\leq Q^2\leq 2.8$ GeV$^2$ and invariant energy from $1.6\leq W\leq 2.4$ GeV, while spanning nearly the full center-of-mass angular range of the kaon. The separated structure functions reveal clear differences between the production dynamics for the $\Lambda$ and $\Sigma^0$ hyperons. These results provide an unprecedented data sample with which to constrain current and future models for the associated production of strangeness, which will allow for a better understanding of the underlying resonant and non-resonant contributions to hyperon production.

531 data tables

Cross sections for incident energy 2.567 GeV for the Q**2 range 0.5 to 0.8 GeV**2 and W range 1.6 to 1.7 GeV.

Cross sections for incident energy 2.567 GeV for the Q**2 range 0.5 to 0.8 GeV**2 and W range 1.70 to 1.75 GeV.

Cross sections for incident energy 2.567 GeV for the Q**2 range 0.5 to 0.8 GeV**2 and W range 1.75 to 1.80 GeV.

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Measurement of the reaction gamma p --> K0 Sigma+ at photon energies up to 2.6-GeV.

Lawall, R. ; Barth, J. ; Bennhold, C. ; et al.
Eur.Phys.J.A 24 (2005) 275-286, 2005.
Inspire Record 680746 DOI 10.17182/hepdata.43595

The reaction gamma p --> K0 Sigma+ was measured in the photon energy range from threshold up to 2.6 GeV with the SAPHIR detector at the electron stretcher facility, ELSA, in Bonn. Results are presented on the reaction cross section and the polarization of the Sigma+ as a function of the kaon production angle in the centre-of-mass system, cos(Theta_K^{c.m.}), and the photon energy. The cross section is lower and varies less with photon energy and kaon production angle than that of gamma p --> K+ Sigma0. The Sigma+ is polarized predominantly at cos(Theta_K^{c.m.}) \approx 0. The data presented here are more precise than previous ones obtained with SAPHIR and extend the photon energy range to higher values. They are compared to isobar model calculations.

14 data tables

Axis error includes +- 10/10 contribution (Normalization uncertainty already included.).

Axis error includes +- 10/10 contribution (Normalization uncertainty already included.).

Axis error includes +- 10/10 contribution (Normalization uncertainty already included.).

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Reaction K- p --> pi0 pi0 lambda from p(K-) = 514-MeV/c to 750-MeV/c.

Prakhov, S. ; Nefkens, B.M.K. ; Allgower, C.E. ; et al.
Phys.Rev.C 69 (2004) 042202, 2004.
Inspire Record 650074 DOI 10.17182/hepdata.25228

Reaction K−p→π0π0Λ was measured at eight incident K− momenta between 514 and 750MeV∕c using the Crystal Ball multiphoton spectrometer. The reaction dynamics are displayed in total cross sections, Dalitz plots, invariant-mass spectra, production angular distributions, and the Λ polarization. The π0π0Λ production is dominated by the π0Σ0(1385) intermediate state; no trace of other light Σ∗ states is observed, and the role of the f0(600) meson appears to be insignificant. A striking similarity is seen between K−p→π0π0Λ and π−p→π0π0n; this can be understood as a consequence of dynamical flavor symmetry.

5 data tables

Measured cross section. Statistical errors only.

Differential cross section for the di-pion system in the c.m. system for incident momenta 514 to 629 MeV.

Differential cross section for the di-pion system in the c.m. system for incident momenta 659 to 750 MeV.

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Measurement of gamma p --> K+ Lambda and gamma p --> K+ Sigma0 at photon energies up to 2.6 GeV

Glander, K.H. ; Barth, J. ; Braun, W. ; et al.
Eur.Phys.J.A 19 (2004) 251-273, 2004.
Inspire Record 626695 DOI 10.17182/hepdata.51677

The reactions gamma p --> K+ Lambda and gamma p --> K+ Sigma0 were measured in the energy range from threshold up to a photon energy of 2.6 GeV. The data were taken with the SAPHIR detector at the electron stretcher facility, ELSA. Results on cross sections and hyperon polarizations are presented as a function of kaon production angle and photon energy. The total cross section for Lambda production rises steeply with energy close to threshold, whereas the Sigma0 cross section rises slowly to a maximum at about E_gamma = 1.45 GeV. Cross sections together with their angular decompositions into Legendre polynomials suggest contributions from resonance production for both reactions. In general, the induced polarization of Lambda has negative values in the kaon forward direction and positive values in the backward direction. The magnitude varies with energy. The polarization of Sigma0 follows a similar angular and energy dependence as that of Lambda, but with opposite sign.

24 data tables

Differential cross sections for the reaction GAMMA P --> K+ LAMBDA in the energy region 0.9 to 1.0 GeV.

Differential cross sections for the reaction GAMMA P --> K+ LAMBDA in the energy region 1.0 to 1.2 GeV.

Differential cross sections for the reaction GAMMA P --> K+ LAMBDA in the energy region 1.2 to 1.4 GeV.

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Measurement of gamma p --> K+ Lambda and gamma p --> K+ Sigma0 at photon energies up to 2-GeV .

The SAPHIR collaboration Tran, M.Q. ; Barth, J. ; Bennhold, C. ; et al.
Phys.Lett.B 445 (1998) 20-26, 1998.
Inspire Record 483236 DOI 10.17182/hepdata.27074

Associated strangeness production in the reactions γp → K + Λ and γp → K + Σ 0 was measured with the SAPHIR detector at the electron stretcher ring ELSA at Bonn. Data on total and differential cross sections and on hyperon polarizations are presented. The total cross section for Λ production shows a strong threshold enhancement whereas the Σ 0 data have a maximum at about E γ =1.45 GeV. Along with the angular decomposition of the differential cross section into polynomials, this suggests resonance production. However, the angular distributions of both hyperon polarizations vary only slightly with the photon energy. Λ and Σ 0 polarizations show opposite signs and change sign over the angular range.

10 data tables

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

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

Differential cross section for the reaction GAMMA P --> K+ LAMBDA in the GAMMA energy range 0.90 to 1.10 GeV in three energy bins.

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A Study of K- n Interactions in the Center-Of-Mass Energy Range from 1.60-GeV to 1.75-GeV

Hepp, V. ; Braun, O. ; Grimm, H.J. ; et al.
Nucl.Phys.B 115 (1976) 82-113, 1976.
Inspire Record 113914 DOI 10.17182/hepdata.8493

We present results of a K − d experiment performed with the 81 cm Saclay deuterium bubble chamber which was exposed to a K − beam at 4 momenta between 680 and 840 MeV/ c at the CERN PS. Cross sections were measured for inelastic two- and three-body K − n reactions on the basis of 5200 events/mb. Resonance production in the three-body reactions is discussed. In addition, differential cross sections and polarisations are presented for inelastic two-body reactions.

59 data tables

CROSS SECTIONS FOR TWO-BODY REACTIONS.

CROSS SECTIONS FOR THREE-BODY REACTIONS.

CROSS SECTIONS FOR K- P REACTIONS.

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A Study of the Reactions anti-K0 p ---> Lambda pi+ and anti-K0 p ---> Sigma0 pi+ from 1-GeV/c to 12-GeV/c

Yamartino, R. ; Brandenburg, G.W. ; Johnson, William B. ; et al.
Phys.Rev.D 10 (1974) 9, 1974.
Inspire Record 91647 DOI 10.17182/hepdata.24927

Cross sections, differential cross sections, and hyperon polarization results are presented for the reactions K¯0p→Λπ+ and K¯0p→Σ0π+ in the momentum interval 1 to 12 GeV/c. Emphasis is placed on the comparison of Λ and Σ channels, and on the momentum dependences of the data. In particular, the Λ polarization data are consistent with being independent of energy above 2 GeV/c; and the slopes of the forward cross sections are found to increase toward the slope values for the line-reversed reactions πp→K(Λ,Σ) as energy increases.

27 data tables

No description provided.

No description provided.

RESONANCE REGION CROSS SECTIONS.

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Differential cross-section and recoil proton polarization of eta-meson photoproduction at 890 mev

Hongoh, M. ; Kikuchi, K. ; Kobayakawa, H. ; et al.
Lett.Nuovo Cim. 2S2 (1971) 317-320, 1971.
Inspire Record 70913 DOI 10.17182/hepdata.37410

None

2 data tables

No description provided.

No description provided.