HEPData Search

The analyzing power of π−p→π0n has been measured for pπ=301−625 MeV/c with a transversely polarized target, mainly in the backward hemisphere. The final-state neutron and a γ from the π0 were detected in coincidence with two counter arrays. Our results are compared with predictions of recent πN partial-wave analyses by the groups of Karlsruhe-Helsinki, Carnegie-Mellon University-Lawrence Berkeley Laboratory (CMU-LBL), and Virginia Polytechnic Institute (VPI). At the lower incident energies little difference is seen among the three analyses, and there is excellent agreement with our data. At 547 MeV/c and above, our data strongly favor the VPI phases, and disagree with Karlsruhe-Helsinki and CMU-LBL analyses, which are the source of the πN resonance parameters given in the Particle Data Group table.

7 data tables

Table 1

Axis error includes +- 5/5 contribution (Uncertainty in background normalisation).

Table 2

Axis error includes +- 5/5 contribution (Uncertainty in background normalisation).

Table 3

Axis error includes +- 5/5 contribution (Uncertainty in background normalisation).

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Measurement of the slope of the pi0 electromagnetic form-factor

Farzanpay, F. ; Gumplinger, P. ; Stetz, A. ; et al.

Phys.Lett.B 278 (1992) 413-418, 1992.

Inspire Record 338523 DOI 10.17182/hepdata.29240

We have measured the slope parameter of the π 0 electromagnetic form factor by measuring the partial branching ratio of the Dalitz decay π 0 → γe + e − into high-invariant-mass electron-positron pairs. We obtain a value a =0.026 with a total (statistical and systematic) error of ±0.054, in agreement with vector dominance and quark loop calculations.

1 data table

Table 1

The PI0 form factor is parameterized as F(M(ee)**2) = 1 + SLOPE*(M(ee)/M(pi))**2. Two metod are used (see text for detail).

New evidence for the p-11(1470) resonance in pi- p ---> n pi0 below 600 mev

Hauser, M.G. ; Chen, K.W. ; Crean, P.A. ;

Phys.Lett.B 35 (1971) 252-256, 1971.

Inspire Record 69248 DOI 10.17182/hepdata.28485

The differential cross section for π − p → n π o has been measured in detail from 150 to 600 MeV. The backward cross section has a previously unobserved dramatic dip at 425 MeV. We interpret this dip in terms of interference between the P 33 (1236) and the P 11 (1470) resonances. These data provide strong evidence for the adequacy of the phase shift solutions in this energy range.

116 data tables

Table 1

SCALED TO AGREE WITH SOLUTION AT 225 MEV AND THEN INTERPOLATED.

Table 2

SCALED TO AGREE WITH SOLUTION AT 225 MEV AND THEN INTERPOLATED.

Table 3

SCALED TO AGREE WITH SOLUTION AT 225 MEV AND THEN INTERPOLATED.

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The reactions pi- p ---> n pi0 and pi- p ---> n eta0 in the backward hemisphere

Boright, J.P. ; Bowen, D.R. ; Groom, Donald E. ; et al.

Phys.Lett.B 33 (1970) 615-619, 1970.

Inspire Record 69352 DOI 10.17182/hepdata.28717

Cross sections for π − p→n π o at 5.9, 10.1 and 13.8 GeV/ c incident momentum are presented in the angular region from 180 o to u , the crossed four-momentum transfer squared, of −2(GeV) 2 and the energy dependence is discussed. The cross section for π − p→n η o integrated over the same angular region at 5.9 GeV/ c is also presented.

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

Study of pi- p ---> pi0 n and pi- p ---> eta n reactions in nuclei at 7.82 gev/c

Guisan, O. ; Bonamy, P. ; Le Du, P. ; et al.

Nucl.Phys.B 32 (1971) 681-690, 1971.

Inspire Record 68531 DOI 10.17182/hepdata.33256

π − p → π 0 n and π − p → η n differential cross sections have been measured in nine nuclei ranging from hydrogen to lead at a 7.82 GeV/ c beam momentum and in a range of t going from 0 to −2 (GeV/ c ) 2 . The results can be understood in the framework of the Glauber theory which allows in addition a determination of the π 0 and η total cross sections on nucleons.

18 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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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

Table 1

Table 2