PBAR P --> PI- PI+
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Proton-antiproton annihilation into pi+ pi- and k+ k- from 700 to 1100 mev/c

Mandelkern, M.A. ; Burns, R.R. ; Condon, P.E. ; et al.
Phys.Rev.D 4 (1971) 2658-2666, 1971.
Inspire Record 74756 DOI 10.17182/hepdata.23118

Total and differential cross sections are presented for proton-antiproton annihilation into π+π− and K+K− at six laboratory momenta between 686 and 1098 MeV/c. The two-pion final state displays moderate energy dependence in its differential cross section, but shows no evidence of any direct-channel resonances. In contrast, the two-kaon final state exhibits some behavior in the total and differential cross section suggestive of a possible direct-channel effect between 800 and 1000 MeV/c.

3 data tables
Table 1

NOTE CUT EXCLUDES LARGE FORWARD CROSS SECTION.

Table 2

LEGENDRE COEFFICIENTS NORMALIZED TO LEGN(L=0) = 0.5.

Table 3

LEGENDRE COEFFICIENTS NORMALIZED TO LEGN(L=0) = 0.5.


Observations on anti-p d annihilations at rest into two pions

Gray, L. ; Papadopoulou, T. ; Simopoulou, E. ; et al.
Phys.Rev.Lett. 30 (1973) 1091-1094, 1973.
Inspire Record 84510 DOI 10.17182/hepdata.21409

The ratio (p¯d→π−π0ps)(p¯d→π−π+n) at rest, with spectator momenta ≲300 MeVc, has been measured and found to be 0.68 ± 0.07. This implies that (75 ± 8)% of the annihilations in deuterium into two pions come from odd N¯N orbital angular momenta, in disagreement with the S-state-dominance hypothesis. It has also been observed that the p¯d→π−π0ps production rate depends on the spectator momentum, which suggests energy-sensitive N¯N phenomena near threshold.

1 data table
Table 1

RELATIVE ANNIHILATION FREQUENCY AT REST.


EXCLUSIVE ANNIHILATION PROCESSES IN 8.8-GEV ANTI-P P INTERACTIONS AND COMPARISONS BETWEEN ANTI-P P NONANNIHILATIONS AND P P INTERACTIONS

Ward, D.R. ; Simmons, A.J. ; Ansorge, R.E. ; et al.
Nucl.Phys.B 172 (1980) 302, 1980.
Inspire Record 158992 DOI 10.17182/hepdata.34487

We give cross sections for annihilation and non-annihilation reactions in p p interactions at 8.8 GeV. The non-annihilation data are compared with pp data from the same experiment. We compare data on resonance production and on the impact parameter structure of the final states in p p annihilation and non-annihilation and pp interactions. We investigate the charge structure of the 2 π + 2 π − π 0 final state, and find it consistent with a simple quark model.

4 data tables
Table 1

NORMALIZED TO A TOTAL AP P CROSS SECTION OF 55.9 MB. ANNIHILATION CROSS SECTIONS.

Table 2

NORMALIZED TO A TOTAL AP P CROSS SECTION OF 55.9 MB. NON-ANNIHILATION CROSS SECTIONS.

Table 3

NORMALIZED TO A TOTAL P P CROSS SECTION OF 40.0 MB.

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Measurement of the anti-Proton-Proton Annihilation Cross-Section Into pi+ pi- Or K+ K- at 300-MeV/c

Bassompierre, G. ; Schneegans, M.A. ; Binder, G. ; et al.
Lett.Nuovo Cim. 20 (1977) 29-33, 1977.
Inspire Record 125074 DOI 10.17182/hepdata.37409

None

1 data table
Table 1

ANNIHILATION INTO CHARGED PION OR KAON PAIRS. THE SEPARATE CROSS SECTIONS FOR PIONS AND KAONS ARE CALCULATED ASSUMING SIG(K+K-)/SIG(PI+PI-) IS 0.33 +- 0.05 FROM INTERPOLATION OF OTHER EXPERIMENTS.


Comparison of new data on anti-p p --> pi- pi+ and other two meson states at 2.3-gev/c

Fields, T. ; Cooper, W.A. ; Rhines, D.S. ; et al.
Phys.Lett.B 40 (1972) 503-506, 1972.
Inspire Record 75681 DOI 10.17182/hepdata.28267

Complete angular distributions for the reactions p p → π − π + and other two meson states at 2.3 GeV/ c are presented. The extraordinary π − π + angular distribution is contrasted with the other final states and the predictions of simple models. A favourable comparison is made with the qualitative features of a dual model involving high mass meson states with a strong degeneracy with respect to I -spin.

2 data tables
Table 1

SOME ANGULAR DISTRIBUTIONS ALSO PRESENTED.

Table 2

K* NEUTRAL TO CHARGED PRODUCTION RATIO.


A formation study of n anti-n interactions between 1.51 and 2.90 gev/c. i. topological and reaction cross-sections

Eastman, P.S. ; Ming, Ma.Z. ; Oh, B.Y. ; et al.
Nucl.Phys.B 51 (1973) 29-56, 1973.
Inspire Record 84299 DOI 10.17182/hepdata.32706

A systematic study of p p and p d topological and reaction cross sections between 1.51 and 2.90 GeV/ c has been completed. The data have been analysed in relation to the three known structures at c.m. N N energies of 2190, 2350 and 2375 MeV. The data suggest that four- and six-pion annihilations of antiprotons on neutrons may be the source of the 2350 MeV effect. Further data below 1.60 GeV/ c are required to verify this tentative conclusion.

3 data tables
Table 1

No description provided.

Table 2

INCLUDING 3 PCT SYSTEMATIC ERROR.

Table 3

No description provided.


A Study of the Reaction anti-p p --> pi- pi+ at 10-GeV/c

Berglund, A. ; Buran, T. ; Carlson, P.J. ; et al.
Nucl.Phys.B 137 (1978) 276-282, 1978.
Inspire Record 135348 DOI 10.17182/hepdata.35092

The reaction p p → π − π + has been studied at 10.1 GeV/ c in the − t interval from 0.15 to 1.5 (GeV/ c ) 2 . A line-reversal comparison with backward elastic scattering π + p → p π + shows good agreement for − t > 0.3 (GeV/ c ) 2 .

2 data tables
Table 1

No description provided.

Table 2

No description provided.


anti-p p Interactions at 2.32-GeV/c

Chen, C.K. ; Fields, T. ; Rhines, D.S. ; et al.
Phys.Rev.D 17 (1978) 42, 1978.
Inspire Record 5667 DOI 10.17182/hepdata.24405

A bubble-chamber experiment based on 304 000 events of p¯p interactions at 2.32 GeV/c is described. The film was automatically scanned and measured by the POLLY II system. Details of the data-analysis methods are given. We report results on cross sections for constrained final states, tests of C invariance, and inclusive pion and ρ0 multiplicity parameters for annihilation final states.

2 data tables
Table 1

Axis error includes +- 4/4 contribution.

Table 2

Axis error includes +- 4/4 contribution.