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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.

The annihilation process p anti-p ---> 2pi+ 2pi- pi0 at 2.5 gev/c

Clayton, J. ; Mason, P. ; Muirhead, H. ; et al.

Nucl.Phys.B 30 (1971) 605-616, 1971.

Inspire Record 68592 DOI 10.17182/hepdata.33476

Substantial production of the resonances ϱ, f and ω has been observed in this reaction. In contrast with the channel p p → 2π + 2π − , associated production of resonances was found to occur. The behaviour of the associated production of ω-mesons with other resonances is shown to be consistent with some very simple assumptions. Alternative methods of displaying data for p p → ππω are discussed; it is shown that the longitudinal phase plot for this reaction is unlike that obtained for any previously reported reaction. Reasonable agreement for the behaviour of this channel is found with the multiperipheral model of Chan, Łoskiewicz and Allison.

2 data tables

Table 1

STATISTICAL ERRORS ONLY. FOR MULTIPLE PI0 PRODUCTION, RESULTS ARE MODEL DEPENDENT.

Table 2

ANALYSIS OF 5PION FINAL STATE. DISTRIBUTION FITTED WITH FIXED MASS AND WIDTH RESONANCES, THEN ONLY EVENTS ABOVE (FITTED) BACKGROUND TAKEN. CROSS SECTIONS CALCULATED BY PDG (COMPILATION PDG3).

Evidence for decays of the d- and e-mesons into delta pi in anti-p p annihilation at 700 mev/c

Defoix, C. ; Do Nascimento, A. ; O' Neall, J.S. ; et al.

Nucl.Phys.B 44 (1972) 125-141, 1972.

Inspire Record 75085 DOI 10.17182/hepdata.32849

A study is made of η 0 production in p p → 3π + 3π − π 0 (7500 events) at an incident momentum of 720 MeV/ c . The reaction is dominated by production of ω 0 (≈68 o/o). The η o production has been studied by means of two independent methods: the first, a study of correlations between the (4 π ) ± and (5 π ) 0 and the (3 π ) 0 systems, circumvents the problem of ω 0 reflections. The second attempts to isolate the η 0 4π channel by means of rigorous selections using the decay properties of η 0 and ω 0 . The results of the two methods are consistent and confirnm the production of σ +- , D 0 and E 0 with the decays ifD 0 → σ ± π ± → η 0 π + π ( su −), E 0 → σ ± π ∓ → η ( su 0) π + π − , E 0 → η 0 π + π − .

1 data table

Table 1

CORRECTED FOR UNOBSERVED ETA DECAYS AND I=0 ASSUMED FOR ETAPRIME, D(1285) AND E(1420) --> ETA PI0 PI0.

ANTI-PROTON - PROTON ANNIHILATION INTO FIVE AND MORE PIONS AT 2.32-GeV/c

Oren, Y. ; Cooper, W.A. ; Fields, T. ; et al.

Nucl.Phys.B 71 (1974) 189-210, 1974.

Inspire Record 80613 DOI 10.17182/hepdata.32346

High statistics data on p p annihilation into five and more pions at 2.32 GeV/ c are presented. Cross sections for various final states and for the production of meson resonances have been determined. The Dalitz plot asymmetry for some 4 800 ω decay events produced in p p → 2π + 2π − π 0 is found to be consistent with zero. Upper limits for the production of exotic meson resonances are presented.

1 data table

Table 1

No description provided.

The pi+ p interaction at 1.2 gev/c

Berthon, A. ; Mas, J. ; Narjoux, J.L. ; et al.

Nucl.Phys.B 81 (1974) 431-444, 1974.

Inspire Record 93412 DOI 10.17182/hepdata.7945

Experimental results are presented for the available channels in the 1.2 GeV/ c π + p interaction. An isobaric model with incoherent addition of the amplitudes is used to determine the π, Δ and N ∗ abundance rates in the π + π o p final state. The multipole parameters in the density matrix of the Δ ++ are determined as functions of its production angle.

7 data tables

Table 1

No description provided.

Table 2

LEGENDRE POLYNOMIAL FIT USED TO CORRECT FOR ELASTIC EVENTS LOST FROM THE FORWARD BIN.

Table 3

No description provided.

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K+ p Interactions Near 3-GeV/c. 2. Baryon Resonance Production

Musgrave, B. ; Peeters, P. ; Schreiner, P. ; et al.

Nucl.Phys.B 87 (1975) 365-398, 1975.

Inspire Record 1720 DOI 10.17182/hepdata.1112

Baryon resonance production in quasi-two-body reactions has been studied for the channels K + p→K°p π + , K + n π + and K + p π ° at beam momenta of 2.53, 2.76 and 3.20 GeV/ c . The production cross sections, four-momentum transfer distributions and density matrix elements are given for the Δ(1236), N ∗ (1400), N ∗ (1500) and N ∗ (1680) states. The reaction K + p→K° Δ ++ (1236) is compared to the line reversed reaction K − n → K °Δ − and the charge-exchange SU(3) sum rule for pseudo-scalar meson plus Δ(1236) is tested.

7 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Study of three quasi-two-body channels from pi + p interactions at 3.9 GeV/c

Haber, B. ; Hodous, M.F. ; Hulsizer, R.I. ; et al.

Phys.Rev.D 11 (1975) 495-509, 1975.

Inspire Record 107224 DOI 10.17182/hepdata.24871

The pπ+π0 and pπ+π+π− final states from π+p interactions at 3.9 GeV/c have been analyzed by the prism-plot technique and the following three quasi-two-body channels have been studied in detail: π+p→ρ+p, π+p→π0Δ++, and π+p→ρ0Δ++. Results are presented on cross sections, differential cross sections, and single and joint spin density matrix elements. These are compared with the Dar-Watts-Weisskopf absorption model and Reggeized pion-exchange model predictions. Relations among joint spin density matrix elements for ρ0Δ++ are compared with quark-model predictions.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Measurement of the Real Part of the Forward Amplitude in anti-p p Elastic Scattering

Jenni, P. ; Baillon, P. ; Bricman, C. ; et al.

Nucl.Phys.B 94 (1975) 1-20, 1975.

Inspire Record 99005 DOI 10.17182/hepdata.31973

The differential cross sections of the elastic p p reaction have been measured at 1.2, 1.4, 1.8 and 2.6 GeV/ c incident p momentum. The measurements have been performed at the CERN PS using a system of multiwire proportional chambers. The angular region covers scattering angles from 0 to ∼200 mrad. Interference effects between the Coulomb and the nuclear amplitudes are used to derive the ratio of the real to imaginary part of the forward nuclear amplitude. These ratios are compared with theoretical predictions.

6 data tables

Table 1

'MS'. 'TBIN'.

Table 2

'MS'. 'TBIN'.

Table 3

'MS'. 'TBIN'.

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Neutron Total Cross-Sections on Nuclei at Fermilab Energies

Ramana Murthy, P.V. ; Ayre, Cyril A. ; Gustafson, H.Richard ; et al.

Nucl.Phys.B 92 (1975) 269-308, 1975.

Inspire Record 2076 DOI 10.17182/hepdata.32056

We have measured total cross sections for neutrons on protons, deuteriom, beryllium, carbon, aluminium, iron, copper, cadmium, tungsten, lead, and uranium for momenta between 30 and 300 GeV/ c . The measurements were carried out in a small-angle neutral beam at Fermilab. Typical accuracy of the data is 0.5 to 1%. The cross sections are consistent with an A 0.77±0.01 dependence over the entire momentum range. The cross sections are compared with theoretical predictions. Agreement is found only if inelastic screening is included. Nuclear radii obtained from our data are in good agreement with previous determinations.

11 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.