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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.

Cross-Sections and Polarizations in the Reactions pi- p --> Lambda K0 and pi- p --> Lambda K* (890) Near the Backward Direction, from 3-GeV/c to 6-GeV/c

Ward, C.E.W. ; Ambats, I. ; Lesnik, A. ; et al.

Phys.Rev.D 16 (1977) 2041, 1977.

Inspire Record 4930 DOI 10.17182/hepdata.24506

We have measured the differential cross sections and Λ polarizations in the reactions π−p→ΛK0 and π−p→ΛK*0 (890) near the backward direction, at 3, 4, 5, and 6 GeV/c. Data equal to several times the world's total sample above 2 GeV/c were recorded. Both reactions are characterized by cross sections falling rapidly with beam momentum, and by large positive Λ polarizations for u′ between 0.0 and 0.6 GeV2. Analysis of π−p→ΛK0 yields an effective Regge trajectory consistent with antishrinkage of the backward peak. Separation into amplitudes of definite-parity-naturality exchange shows the reaction to be dominated by unnatural-parity exchange. The energy behavior of this exchange is, however, not consistent with a single linear baryon Regge trajectory or exchange-degenerate pair of trajectories. An apparent normalization discrepancy between data on π−p→ΛK0 of a CERN-ETH group and other high-statistics data including that of this experiment is discussed.

10 data tables

Table 1

No description provided.

Table 2

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Table 3

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Measurements of Polarization and Spin Rotation in Proton Proton Elastic Scattering at 3.83-GeV/c

Deregel, J. ; Bruneton, C. ; Bystricky, J. ; et al.

Nucl.Phys.B 103 (1976) 269-278, 1976.

Inspire Record 113032 DOI 10.17182/hepdata.35989

The polarization P in proton-proton elastic scattering has been measured at 3.83 GeV/ c for 0.35 ⩽ | t | ⩽ 3.0 (GeV/ c ) 2 , i.e. 29° ⩽ θ c.m. ⩽ 93°. The polarization shows a minimum at − ⋍ 1.0 ( GeV /c) 2 followed by a maximum at −⋍1.5 ( GeV /c) 2 . At the same energy the spin rotation parameter R has been measured in the interval 0.18 ⩽ | t | ⩽ 0.57 (GeV/ c ) 2 . Comparison with the results at 6.0 and 15.75 GeV/ c shows a similar t -dependence and the same average value at all three energies.

5 data tables

Table 1

POLARIZED TARGET ASYMMETRY EQUALS RECOIL PROTON POLARIZATION BY TIME REVERSAL INVARIANCE.

Table 2

'A'. 'B'. 'D'.

Table 3

'A'. 'B'. 'C'. 'E'.

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Photoproduction of pi+ Mesons on Polarized Protons

Genzel, H. ; Heide, P. ; Knutel, J. ; et al.

Nucl.Phys.B 92 (1975) 196-206, 1975.

Inspire Record 98235 DOI 10.17182/hepdata.32060

The asymmetry of the cross sections for the photoproduction of π + mesons on polarized protons γ + p↑ → π + + n has been studied in the four-momentum transfer range 0.1 ⩽ | t | ⩽ 1.25 (GeV/ c ) 2 for photon energies of 2.5, 3.4 and 5.0 GeV. The measurements were carried out on a polarized butanol target. Both particles in the final state were detected: the pion by a magnetic spectrometer, the recoil nucleon in a scintillation counter matrix. The asymmetry was found to be negative with values around −0.4.

3 data tables

Table 1

No description provided.

Table 2

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Table 3

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Recoil-proton polarization in neutral-pion photoproduction and in proton Compton scattering

Deutsch, M. ; Golub, L. ; Kijewski, P. ; et al.

Phys.Rev.Lett. 29 (1972) 1752-1755, 1972.

Inspire Record 84562 DOI 10.17182/hepdata.21426

We have measured the polarization of the recoil proton in the reactions γp→π0p and γp→γp for incident photon energies between 3 and 7 GeV, and t values from -0.2 to -0.65 GeV2. The polarization in neutral-pion production varies from 0 to -1 over this range. Contrary to expectation, it does not agree completely with the polarized-target asymmetry.

1 data table

Table 1

No description provided.

Vector Meson Production by Polarized Photons at 2.8-GeV, 4.7-GeV, and 9.3-GeV

Ballam, Joseph ; Chadwick, G.B. ; Eisenberg, Y. ; et al.

Phys.Rev.D 7 (1973) 3150, 1973.

Inspire Record 73602 DOI 10.17182/hepdata.43496

We present results on vector-meson photoproduction via γp→Vp in the LBL-SLAC 82-in. hydrogen bubble chamber exposed to a linearly polarized photon beam at 2.8, 4.7, and 9.3 GeV. We find ρ0 production to have the characteristics of a diffractive process, i.e., a cross section decreasing slowly with energy and a differential cross section with slope of ∼ 6.5 GeV−2. Within errors the ρ0 production amplitudes are entirely due to natural-parity exchange. s-channel helicity is conserved to a high degree in the γ→ρ0 transition. We find evidence for small helicity-flip amplitudes for ππ pairs in the ρ0 region. Photoproduction of ω mesons is separated into its natural- (σN) and unnatural- (σU) parity-exchange contributions. The Eγ and t dependence and the spin density matrix of the unnatural-parity-exchange contribution are consistent with a one-pion-exchange process. The natural-parity-exchange part has characteristics similar to ρ0 production. At 9.3 GeV the ratio of σ(ρ0) to σN(ω) is ∼ 7. The slope of the φ differential cross section is ∼ 4.5 GeV−2, smaller than that of ρ0 and ω production. Natural-parity exchange is the main contributor to φ production. No evidence for higher-mass vector mesons is found in ππ, πππ, or KK¯ final states. The s and t dependences of Compton scattering as calculated from ρ, ω, and φ photoproduction using vector-meson dominance agree with experiment, but the predicted Compton cross section is too small by a factor of 2.

47 data tables

Table 1

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Table 3

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