HEPData Search

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

Table 1

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

Table 1

Table 2

Table 3

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

Table 1

Table 2

Measurements of spin rotation parameter A in pion proton elastic scattering at 1.62-GeV/c.

The ITEP-PNPI collaboration Alekseev, I.G. ; Budkovsky, P.E. ; Kanavets, V.P. ; et al.

Phys.Lett.B 485 (2000) 32-36, 2000.

Inspire Record 526552 DOI 10.17182/hepdata.41744

The ITEP-PNPI collaboration presents the results of the measurements of the spin rotation parameter A in the elastic scattering of positive and negative pions on protons at P_beam = 1.62 GeV/c. The setup included a longitudinally-polarized proton target with superconductive magnet, multiwire spark chambers and a carbon polarimeter with thick filter. Results are compared to the predictions of partial wave analyses. The experiment was performed at the ITEP proton synchrotron, Moscow.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Measurement of the spin rotation parameter A+ in the elastic scattering of positive pions on a longitudinally polarized proton target in the second resonance region

The ITEP-PNPI collaboration Alekseev, I.G. ; Bobchenko, B.M. ; Budkovsky, P.E. ; et al.

Phys.Lett.B 351 (1995) 585-590, 1995.

Inspire Record 403317 DOI 10.17182/hepdata.28540

The ITEP-PNPI collaboration presents the first results of the spin rotation parameter A + measurements in the second resonance region. The experiment was performed at the ITEP accelerator at a positive pion beam momentum 1.43 GeV/c for scattering angles θ cm = 127° and 133°. The setup was based on a polarized proton target and a carbon-plate polarimeter. The obtained data is compared with the predictions of the existing partial-wave analyses.

1 data table

Table 1

No description provided.

Observation of significant spin effects in hard collisions at 40-GeV/c

Apokin, V.D. ; Arestov, Yu.I. ; Astafev, O.V. ; et al.

Phys.Lett.B 243 (1990) 461-464, 1990.

Inspire Record 303587 DOI 10.17182/hepdata.29694

A single-spin asymmetry in the inclusive π 0 production at small x F was measured. In the experiment 40 GeV/c π − mesons were incident on transversely polarized protons and deutrons. An asymmetry of (40–50)% has been revealed in the hard scattering region.

1 data table

Table 1

No description provided.