PBAR P --> PI- A2(1320)+
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Four-pion final state in anti-p p annihilations at 940 mev/c

Burns, R.R. ; Condon, P.E. ; Donahue, J. ; et al.
Nucl.Phys.B 27 (1971) 109-124, 1971.
Inspire Record 68769 DOI 10.17182/hepdata.33655

Resilts are reported on the four-pion final state from antiproton annihilations in hydrogen in the vicinity of 940 MeV/ c . The cross section for π − π − π + π + is found to be 3.6 mb. Abundant resonance production is observed, with fits indicating that quasi-two-body production constitutes approximately half the four-pion events. The model employed, which includes resonance production and Bose symmetrization, yields excellent fits to mass distributions and angular correlations.

2 data tables
Table 1

ASSUMING TOTAL AP P CROSS SECTION OF 122 MB. ERRORS INCLUDE SYSTEMATIC UNCERTAINTIES.

Table 2

ANALYSIS OF 4PION FINAL STATE. FIXED MASS AND WIDTH BREIT-WIGNER RESONANCES AND BACKGROUND FITTED TO DATA. CROSS SECTIONS CALCULATED BY PDG (COMPILATION PDG3). ERROR GIVEN IS SCATTER FROM VARIOUS FITS.


Properties of the $\bar{p} p$ Annihilations Into Strange Particles at 702-{MeV}/$c$ and 757-{MeV}/$c$

The India-CERN-College de France-Madrid-Pisa collaboration Ganguli, S.N. ; Gurtu, A. ; Malhotra, P.K. ; et al.
Nucl.Phys.B 183 (1981) 295-329, 1981.
Inspire Record 154814 DOI 10.17182/hepdata.49299

p p annihilations, leading to the production of at least one neutral K meson in the final state, have been studied in the incident momentum region of 700–760 MeV/ c . Topological cross sections and cross sections for the various exclusive final states are presented. Detailed analyses of the different final states have been carried out to study the importance of resonance production and of quasi two-body and quasi three-body processes. A detailed study of the K K π system in the four-body final states shows that the F 1 meson is a spurious effect due to systematic biases. In the momentum range investigated, the C = +1 final states are strongly suppressed.

3 data tables
Table 1

SUMMARY OF QUASI-TWO-BODY CROSS SECTIONS.

Table 2

No description provided.

Table 3

No description provided.


Anti-p p Annihilations Into Four and Five Pion Final States in the t (2190) Region

Handler, T. ; Jacques, P. ; Jones, M. ; et al.
Nucl.Phys.B 101 (1975) 35, 1975.
Inspire Record 99552 DOI 10.17182/hepdata.36053

New data from a 600 000 picture exposure of the BNL 31 inch hydrogen bubble chamber to a separated antiproton beam have been analyzed to try to determine if the π + π − π + π − or π + π − π + π − π 0 final states contribute any broad or narrow structure in the T(2190) region. The resonance channel fractions determined by maximum likelihood fits are all consistent with smooth behavior through the T-region and therefore there is no significant evidence that any of these resonance channels contributes to the broad bump in the total cross section. The errors on some of the fractions, however, limit the sensitivity to ∼ 0.5 mb for enhancements in these channels.

2 data tables
Table 1

RESONANCE CHANNEL PERCENTAGES FROM FIT TO PI+ PI- PI+ PI- FINAL STATE.

Table 2

RESONANCE CHANNEL PERCENTAGES FROM FIT TO PI+ PI- PI+ PI- PI0 FINAL STATE.


Anti-p p annihilations into four charged mesons from 1.6 to 2.2 gev/c

Davidson, J. ; Chapman, J.W. ; Green, R.W. ; et al.
Phys.Rev.D 9 (1974) 77-90, 1974.
Inspire Record 93127 DOI 10.17182/hepdata.21951

The following reactions have been analyzed: (1) p¯p→π−π−π+π+; (2) p¯p→π−π+K−K+; (3) p¯p→K−K−K+K+. Cross sections as a function of beam momentum ranging from 1.6 to 2.2 GeVc are presented. The percentage of resonance production in reaction (1) is examined using the maximum-likelihood (ML) method. The channel is dominated by ρππ and ρf production. The percentage of ρf decreases with p¯ momentum, while ρππ appears to increase. ML fits are also made to reaction (2); the reaction is dominated by K*Kπ, ϕππ, and ρKK production. An enhancement is seen in the Q region of the ππK mass spectrum at 1278 MeV, with FWHM (full width at half maximum) of 25 MeV. Six events are consistent with reaction (3). Mass spectra indicate that five events have at least one ϕ meson produced; one of these is a ϕϕ event.

3 data tables
Table 1

NORMALIZED TO KNOWN TOTAL CROSS SECTION.

Table 2

'FIT 9'. ENERGY DEPENDENCE AND EFFECT OF BOSE-EINSTEIN STATISTICS ALSO STUDIED.

Table 3

'FIT F'.


anti-Proton-Proton Annihilations Between 1.5-GeV/c and 2.0-GeV/c: Final States with at Least One K0(L) Meson

Vuillemin, V. ; Gailloud, M. ; Rosselet, P. ; et al.
Nuovo Cim.A 33 (1976) 133, 1976.
Inspire Record 3307 DOI 10.17182/hepdata.37675

Antiproton-proton annihilations into final states containing one or two K10-mesons are studied on the basis of 450 000 pictures from the CERN 2 m HBC. The experiment covers the domain of antiproton incident momentum from 1.50 to 2.04 GeV/c. The resonance production rates are computed for the most abundant channels. The K10K10 threshold effect is explained through the inelastic channel π+π− → K10K10. The decay modes D, E → δ±(975)π∓, δ±(975) → K10K± are pointed out. The strange mesons C and C′ are observed in these annihilations and come mainly from the two-body channels \(p\bar p\) → (C, C′)K and\(p\bar p\) → (C, C′)K*.

9 data tables
Table 1

RESONANCE FRACTIONS FOR AP P --> KS (K+ PI- + K- PI+).

Table 2

RESONANCE FRACTIONS FOR AP P --> KS (K+ PI- + K- PI+) PI0.

Table 3

RESONANCE FRACTIONS FOR AP P --> KS KS PI+ PI-.

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Strange Particle Production in anti-p p Annihilation from 1.22-GeV/c to 1.35-GeV/c

Handler, T. ; Plano, R.J. ; Brucker, E.B. ; et al.
Nucl.Phys.B 110 (1976) 173-188, 1976.
Inspire Record 100479 DOI 10.17182/hepdata.35744

Experimental results on antiproton-proton annihilations at 5 incident momenta in the range 1.22–1.35 GeV/ c into final states with at least one visible K 1 0 meson are presented. Based on a total of 5855 events, cross sections and resonance fractions for all experimentally accessible final states are determined. The total cross section for annihilation into strange particles with at least one visible K 1 0 is 2069 ± 45 ub. Copious resonance production is observed but there is no significant evidence for the formation of a resonance in the s -channel.

7 data tables
Table 1

No description provided.

Table 2

RESONANCE FRACTIONS AND CROSS SECTIONS FOR AP P --> KS (K+ PI- + K- PI+).

Table 3

RESONANCE FRACTIONS AND CROSS SECTIONS FOR AP P --> KS (K+ PI- + K- PI+) PI0.

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Peripheral Behavior of anti-p p --> K*+- K-+ Between 1-GeV/c and 2.5-GeV/c

Baubillier, M. ; De Billy, L. ; Rivoal, M. ; et al.
Nucl.Phys.B 104 (1976) 277-289, 1976.
Inspire Record 113110 DOI 10.17182/hepdata.35964

The reaction p p → K ∗ K does not exhibit any s -channel resonance effect between 1 and 2.5 GeV/ c . On the contrary, the data on p p → K ∗∓ K ± are compatible with an exchange mechanism in the t - and u -channels above 1.5 GeV/ c . Strong similarities are found with p p → K − K + and K ∗− K ∗+ . The polarisation of K ∗± is given. The reaction p p → K ∗0 K 0 vanishes above 1.5 GeV/ c

7 data tables
Table 1

No description provided.

Table 2

LEG(L=0) = SIG/(4*PI).

Table 3

LEG(L=0) = SIG/(4*PI).

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