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The results on measuring polarization in charge exchange reaction π−+p→π0+n at 40 GeV/c are presented for the 4-momentum transfer range from 0 up to 2 (GeV/c)2. At |t|≦0.4 (GeV/c)2 the polarization has a positive sign. In the “crossover” region of π± elastic scattering a possible minimum in the polarization behaviour has been seen for the first time. the polarization is zero within the statistical accuracy near this point. In the “deep” region of the charge-exchange differential cross-section the polarization has a negative sign. The presented data are not in agreement with the modern theoretical models.

1 data table

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Production asymmetry measurement of high x(T) hadrons in p(pol.) p collisions at 40-GeV.

Abramov, V.V. ; Dyshkant, A.S. ; Evdokimov, V.N. ; et al.

Nucl.Phys.B 492 (1997) 3-17, 1997.

Inspire Record 429347 DOI 10.17182/hepdata.40519

Single-spin asymmetries for hadrons have been measured in collisions of transversely-polarized 40 GeV/c proton beam with an unpolarized liquid hydrogen target. The asymmetries were measured for pi+-, K+-, protons and antiprotons, produced in the central region (0.02 < Xf < 0.10 and 0.7 < Pt < 3.4 GeV/c). Asymmetries for pi+-, K+- and antiprotons show within measurement errors the linear dependence on Xt and change a sign near 0.37. For protons negative asymmetry, independent of Xt has been found. The results are compared with those of other experiments and SU(6) model predictions.

3 data tables

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A-dependence of Polarization of $\Lambda^0$ Produced Inclusively in Neutron - Nucleus Interactions

The BIS-2 collaboration Aleev, A.N. ; Arefev, V.A. ; Balandin, V.P. ; et al.

Z.Phys.C 36 (1987) 27, 1987.

Inspire Record 237043 DOI 10.17182/hepdata.39599

TheA-dependence of the polarization ofΛ0,s produced inclusively in neutron-nucleus interactions at a mean neutron momentum of about 40 GeV/c has been measured in an experiment performed using the BIS-2 spectrometer at the Serpukhov accelerator. Carbon, Aluminium and Copper targets were used. TheΛ0,s were produced in the kinematical region of 0.6<pT<1.3 GeV/c and 0.2<xF<0.9. Describing the polarization of theΛ0,s by ℘=a·A a value of (−0.15+0.07/−0.60) was obtained by a fit to our data.

2 data tables

Table 1

POLARIZATION IS DESCRIBED BY A POWER LOW: POL = C*A**B, WHERE C = -1.1, +0.4, -0.3 , A- ATOMIC NUMBER AND B = -0.15, +0.07, -0.6.

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Polarization Parameters in the Reactions $\pi^- p$ (Polarized) $\to \eta n$ and $\pi^- p$ (Polarized) $\to \eta^\prime n$ at 40-{GeV}/$c$

Apokin, V.D. ; Arestov, Yu.I. ; Avvakumov, I.A. ; et al.

Z.Phys.C 35 (1987) 173, 1987.

Inspire Record 222760 DOI 10.17182/hepdata.40802

The polarization parameter in the reactions π−p→ηn and π−p→η′n at 40 GeV/c with −t ranging from 0 to 2.6 (GeV/c)2 and 1.0 (GeV/c)2, respectively, was measured in experiments using a propanediol polarized target. Only gamma particles from the neutral meson decay were detected. The polarization parameter of the first reaction turns out to be negative in a widet interval (0.05<−t<1.6 (GeV/c)2) and probably changes its sign at larger values oft. The average value of the polarization parameter of the second reaction is equal to −17±8)% in the region 0.05<−t<0.5 (GeV/c)2.

3 data tables

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Polarization in the Reaction $\pi^-$ Polarized $p \to \pi^0 n$ at 40-{GeV}/$c$

Avvakumov, I.A. ; Apokin, V.D. ; Bagaturiya, Yu.Sh. ; et al.

Nucl.Phys.B 255 (1985) 253-272, 1985.

Inspire Record 206940 DOI 10.17182/hepdata.33791

The paper presents results on measuring the polarization in the reaction π − p→ π 0 n at 40 GeV/ c in the 4-momentum transfer range 0<| t |⩽2 (GeV/ c ) 2 . The results based on the statistics of about 2.2 million recorded events made it possible to observe a noticeable value and complex structure in the polarization behaviour up to | t |⩽2 (GeV/ c ) 2 .

2 data tables

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Measurement of single spin asymmetry in eta meson production in p(pol.) p and in anti-p(pol.) p interactions in the beam fragmentation region at 200-GeV/c.

The Fermilab E704 collaboration Adams, D.L. ; Bonner, B.E. ; Corcoran, M.D. ; et al.

Nucl.Phys.B 510 (1998) 3-11, 1998.

Inspire Record 449811 DOI 10.17182/hepdata.51687

We present experimental results on measuring a single spin asymmetry in η-meson production in the interaction of transversely polarized protons and antiprotons at p lab = 200 GeV / c with a proton target in the region 0.2 < x F < 0.7 for p ↑ p , 0.3 < x F < 0.7 for p ̄ ↑p and 0.7 < p T < 2.0 GeV / c . A comparison of single spin asymmetries in π- and η-meson production is made.

2 data tables

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The true asymmetry for ETA production in proton-proton collisions.

Table 2

The true asymmetry for ETA production in antiproton-proton collisions.

Beam asymmetry $\Sigma$ measurements on the $\pi^-$ photoproduction off neutrons

The Graal collaboration Mandaglio, G. ; Mammoliti, F. ; Manganaro, M. ; et al.

Phys.Rev.C 82 (2010) 045209, 2010.

Inspire Record 872319 DOI 10.17182/hepdata.63833

The $\Sigma$ beam asymmetry in the photoproduction of negative pions from quasi-free neutrons in a deuterium target was measured at Graal in the energy interval 700 - 1500 MeV and a wide angular range, using polarized and tagged photons. The results are compared with recent partial wave analyses.

11 data tables

Table 1

The measured beam polarization asymmetry for photon energy 753 MeV.

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The measured beam polarization asymmetry for photon energy 820 MeV.

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The measured beam polarization asymmetry for photon energy 884 MeV.

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Measurement of eta photoproduction on the proton from threshold to 1500-MeV

The GRAAL collaboration Bartalini, O. ; Bellini, V. ; Bocquet, J.P. ; et al.

Eur.Phys.J.A 33 (2007) 169-184, 2007.

Inspire Record 755415 DOI 10.17182/hepdata.51526

Beam asymmetry and differential cross section for the reaction gamma+p->eta+p were measured from production threshold to 1500 MeV photon laboratory energy. The two dominant neutral decay modes of the eta meson, eta->2g and eta->3pi0, were analyzed. The full set of measurements is in good agreement with previously published results. Our data were compared with three models. They all fit satisfactorily the results but their respective resonance contributions are quite different. The possible photoexcitation of a narrow state N(1670) was investigated and no evidence was found.

45 data tables

Table 1

Measured beam asymmetry at photon energy 724 MeV as a function of the ETA centre of mass angle.

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Measured beam asymmetry at photon energy 761 MeV as a function of the ETA centre of mass angle.

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Measured beam asymmetry at photon energy 810 MeV as a function of the ETA centre of mass angle.

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Measurement of the polarization parameter P in elastic π+p scattering at 335, 370, and 410 MeV

Asymmetry of the cross section of the reaction $\gamma$P $\rightarrow$ P$\pi^{0}$ in the energy interval 0.9-1.65 GeV at $\theta _{\pi}^{0 cms}$ = 110°

Polarization in Charge Exchange Reaction $\pi^- p \to \pi^0 n$ at 40-{GeV}/$c$ for the Four Momentum Transfer Range $0 < T < 2$-{GeV}/$c^2$

Production asymmetry measurement of high x(T) hadrons in p(pol.) p collisions at 40-GeV.

A-dependence of Polarization of $\Lambda^0$ Produced Inclusively in Neutron - Nucleus Interactions

Polarization Parameters in the Reactions $\pi^- p$ (Polarized) $\to \eta n$ and $\pi^- p$ (Polarized) $\to \eta^\prime n$ at 40-{GeV}/$c$

Polarization in the Reaction $\pi^-$ Polarized $p \to \pi^0 n$ at 40-{GeV}/$c$

Measurement of single spin asymmetry in eta meson production in p(pol.) p and in anti-p(pol.) p interactions in the beam fragmentation region at 200-GeV/c.

Beam asymmetry $\Sigma$ measurements on the $\pi^-$ photoproduction off neutrons

Measurement of eta photoproduction on the proton from threshold to 1500-MeV