Robbiano, A
Strange production
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Differential cross section and photon beam asymmetry for the gamma(pol.) n --> K+ Sigma- reaction at e(gamma) = 1.5-GeV - 2.4-GeV.

Kohri, H. ; Ahn, D.S. ; Ahn, J.K. ; et al.
Phys.Rev.Lett. 97 (2006) 082003, 2006.
Inspire Record 709901 DOI 10.17182/hepdata.41825

Differential cross sections and photon beam asymmetries have been measured for the gamma n -> K+ Sigma- and gamma p -> K+ Sigma0 reactions separately using liquid deuterium and hydrogen targets with incident linearly polarized photon beams of Egamma=1.5-2.4 GeV at 0.6<cosTheta<1. The cross section ratio of sigma(K+Sigma-)/sigma(K+Sigma0), expected to be 2 on the basis of the isospin 1/2 exchange, is found to be close to 1. For the K+Sigma- reaction, large positive asymmetries are observed indicating the dominance of the K*-exchange. A large difference between the asymmetries for the K+Sigma- and K+Sigma0 reactions can not be explained by simple theoretical considerations.

4 data tables
Table 1

Differential cross section for GAMMA P --> K+ SIGMA0.. Errors are statistical only.

Table 2

Photon beam asymmetry for GAMMA N --> K+ SIGMA-.. Errors are statistical only.

Table 3

Photon beam asymmetry for GAMMA P --> K+ SIGMA0.. Errors are statistical only.

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The gamma(pol.) p --> K+ Lambda and gamma(pol.) p --> K+ Sigma0 reactions at forward angles with photon energies from 1.5-GeV to 2.4-GeV.

The LEPS collaboration Sumihama, M. ; Ahn, J.K. ; Akimune, H. ; et al.
Phys.Rev.C 73 (2006) 035214, 2006.
Inspire Record 701097 DOI 10.17182/hepdata.41824

Differential cross sections and photon beam asymmetries for the gamma p rightarrow K+ Lambda and gamma p rightarrow K+ Sigma0 reactions have been measured in the photon energy range from 1.5 GeV to 2.4 GeV and in the angular range from Theta_{cm} = 0 to 60 of the K+ scattering angle in the center of mass system at the SPring-8/LEPS facility. The photon beam asymmetries for both the reactions have been found to be positive and to increase with the photon energy. The measured differential cross sections agree with the data measured by the CLAS collaboration at cosTheta_{cm}<0.9 within the experimental uncertainties, but the discrepancy with the SAPHIR data for the K+Lambda reaction is large at cosTheta_{cm}>0.9. In the K+Lambda reaction, the resonance-like structure found in the CLAS and SAPHIR data at W=1.96 GeV is confirmed. The differential cross sections at forward angles suggest a strong K-exchange contribution in the t-channel for the K+Lambda reaction, but not for the K+Sigma0 reaction.

14 data tables
Table 1

Photon beam asymmetries for the two reactions as a function of CM angle for photon beam energy 1.55 GeV (W=1.947 GeV).

Table 2

Photon beam asymmetries for the two reactions as a function of CM angle for photon beam energy 1.65 GeV (W=1.994 GeV).

Table 3

Photon beam asymmetries for the two reactions as a function of CM angle for photon beam energy 1.75 GeV (W=2.041 GeV).

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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
Table 1

Measured cross section. Statistical errors only.

Table 2

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

Table 3

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

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A measurement of $\Lambda$ polarization in inclusive production by $\Sigma^-$ of 340-GeV/c in C and Cu targets

The WA89 collaboration Adamovich, M.I. ; Alexandrov, Yu.A. ; Baranov, S.P. ; et al.
Eur.Phys.J.C 32 (2004) 221-228, 2004.
Inspire Record 645459 DOI 10.17182/hepdata.43190

We have measured the polarization of $\Lambda$ hyperons produced inclusively by a $\Sigma^-$ beam of 340 GeV/c momentum in nuclear targets. From a sample of 9.5 millions of identified $\Lambda$ decays, polarizations were determined in the range $x_F \gt 0.1$ and $p_t\leq 1.6$ GeV/c . The polarization w.r.t. the production normal is mainly positive for $x_F \geq 0.3$. At fixed values of $x_F$, it increases with $p_t$ to a maximum between $p_t = 0.5$ and $p_t = 1$ GeV/c , and then decreases to zero or even negative values, in sharp contrast to the plateau above $p_t = 1$ GeV/c observed in inclusive $\Lambda$ production by protons.

8 data tables
Table 1

Measured values of the LAMBDA polarization as a function of PT in the XL range 0.1 to 0.2.

Table 2

Measured values of the LAMBDA polarization as a function of PT in the XL range 0.2 to 0.3.

Table 3

Measured values of the LAMBDA polarization as a function of PT in the XL range 0.3 to 0.4.

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Beam polarization asymmetries for the p(gamma,K+)Lambda and p(gamma,K+)Sigma0 reactions at E(gamma) = 1.5-GeV - 2.4-GeV.

The LEPS collaboration Zegers, R.G.T. ; Sumihama, M. ; Ahn, D.S. ; et al.
Phys.Rev.Lett. 91 (2003) 092001, 2003.
Inspire Record 613016 DOI 10.17182/hepdata.31708

Beam polarization asymmetries for the p(gamma,K+)Lambda and p(gamma,K+)sigma0 reactions are measured for the first time for Egamma=1.5-2.4 GeV and 0.6<cos(theta_cm(K+))<1.0 by using linearly polarized photons at the Laser-Electron-Photon facility at SPring-8 (LEPS). The observed asymmetries are positive and gradually increase with rising photon energy. The data are not consistent with theoretical predictions based on tree-level effective Lagrangian approaches. Including the new results in the development of the models is, therefore, crucial for understanding the reaction mechanism and to test the presence of baryon resonances which are predicted in quark models but are sofar undiscovered.

18 data tables
Table 1

Measured beam asymmetries for the reaction GAMMA P --> K+ LAMBDA for beam energy 1.5 to 1.6.

Table 2

Measured beam asymmetries for the reaction GAMMA P --> K+ LAMBDA for beam energy 1.6 to 1.7.

Table 3

Measured beam asymmetries for the reaction GAMMA P --> K+ LAMBDA for beam energy 1.7 to 1.8.

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Lambda0 polarization in 800-GeV/c p p --> p(f) (Lambda0 K+).

The E690 collaboration Felix, J. ; Berisso, M.C. ; Christian, D.C. ; et al.
Phys.Rev.Lett. 88 (2002) 061801, 2002.
Inspire Record 560899 DOI 10.17182/hepdata.42919

We report results from a study of Λ0 polarization in the exclusive reaction pp→pf(Λ0K+) at 800−GeV/c. We observe a dependence of the polarization on the Λ0K+ invariant mass with large (+71%) positive polarization at small mass (1.63−GeV/c2) and large (−43%) negative polarization at large mass (2.75−GeV/c2). This observation confirms the result of the CERN ISR R608 experiment and extends the range over which the effect is observed. The strong dependence of the polarization on the Λ0K+ invariant mass suggests that the origin of the polarization is closely related to the production dynamics of the diffractively produced Λ0K+ system.

2 data tables
Table 1

The measured LAMBDA polarisation as a function of the (LAMBDA K+) invariantmass.

Table 2

The measured LAMBDA polarisation as functions of the LAMBDA transverse momentum and Feynman X.


Measurement of the Antilambda polarization in nu/mu charged current interactions in the NOMAD experiment.

The NOMAD collaboration Astier, P. ; Autiero, D. ; Baldisseri, A. ; et al.
Nucl.Phys.B 605 (2001) 3-14, 2001.
Inspire Record 554759 DOI 10.17182/hepdata.48928

We present a measurement of the polarization of Antilambda hyperons produced in nu_mu charged current interactions. The full data sample from the NOMAD experiment has been analyzed using the same V0 identification procedure and analysis method reported in a previous paper for the case of Lambda hyperons. The Antilambda polarization has been measured for the first time in a neutrino experiment. The polarization vector is found to be compatible with zero.

2 data tables
Table 1

Lambdabar polarization in regions of Feynman X (XL).

Table 2

Lambdabar polarization in regions of the Bjorken scaling variable X.


Measurement of K- p --> eta Lambda near threshold

The Crystal Ball collaboration Starostin, A. ; Nefkens, B.M.K. ; Berger, E. ; et al.
Phys.Rev.C 64 (2001) 055205, 2001.
Inspire Record 569202 DOI 10.17182/hepdata.25269

We present measurements of the differential and total cross sections and the Λ polarization for the reaction K−p→ηΛ from threshold to pK−=770MeV/c, with much better precision than previous measurements. Our cross-section data show a remarkable similarity to the SU(3) flavor-related π−p→ηn cross-section results. The reaction K−p→ηΛ at threshold is dominated by formation of the intermediate Λ(1670)12− state.

5 data tables
Table 1

Total cross section measurement for K- P --> ETA LAMBDA. Errors shown are statistical only.

Table 2

Differential cross sections DSIG/DOMEGA for K- P --> ETA LAMBDA. Errors shown are statistical only.

Table 3

Differential cross sections DSIG/DOMEGA for K- P --> ETA LAMBDA. Errors shown are statistical only.

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Lambda and Antilambda polarization from deep inelastic muon scattering

The E665 collaboration Adams, M.R. ; Aderholz, M. ; Aid, S. ; et al.
Eur.Phys.J.C 17 (2000) 263-267, 2000.
Inspire Record 509690 DOI 10.17182/hepdata.43315

We report results of the first measurements of Lambda and Antilambda polarization produced in deep inelastic polarized muon scattering on the nucleon. The results are consistent with an expected trend towards positive polarization with increasing x_F. The polarizations of Lambda and Antilambda appear to have opposite signs. A large negative polarization for Lambda at low positive x_F is observed and is not explained by existing models.A possible interpretation is presented.

2 data tables
Table 1

The measured and corrected (undiluted) polarizations.

Table 2

The measured and corrected (undiluted) polarizations.


Measurement of gamma p --> K0 Sigma+ at photon energies up to 1.55-GeV.

The SAPHIR collaboration Goers, S ; Barth, J ; Bennhold, C ; et al.
Phys.Lett.B 464 (1999) 331-338, 1999.
Inspire Record 512574 DOI 10.17182/hepdata.27045

The reaction γp → K 0 Σ + has been measured with the SAPHIR detector at the electron stretcher ring ELSA. The total cross section rises up to a peak value of 1.1 μ b at a photon energy of 1.4 GeV. The differential cross sections dσ/dΩ are consistent with being flat throughout the measured energy range. The first measurement of the Σ + polarization in photon induced reactions was obtained.

3 data tables
Table 1

Total cross section for the reaction GAMMA P --> K0 SIGMA+. Errors include statistics and the uncertainty on the acceptance calculation and photon flux.

Table 2

Differential cross section for the reaction GAMMA P --> K0 SIGMA+. Errors are dominated by statistical uncertainties.

Table 3

Measure of SIGMA+ polarization in the reaction GAMMA P --> K0 SIGMA+.