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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.

2 data tables match query

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.

MEASUREMENT OF THE TOTAL CROSS-SECTION DIFFERENCE DELTA (SIGMA-L) (P P IN THE ENERGY RANGE FROM 0.52-GEV TO 2.8-GEV

Bystricky, J. ; Chaumette, P. ; Deregel, J. ; et al.

Phys.Lett.B 142 (1984) 130-134, 1984.

Inspire Record 206656 DOI 10.17182/hepdata.30540

The total cross section difference Δα L (pp) for proton-proton scattering with beam and target polarized longitudinally parallel and antiparallel, respectively, has been measured using the polarized proton beam from SATURNE II and a frozen spin polarized proton target. The beam polarization was reversed from pulse to pulse, and at each energy Δα L was measured for both signs of target polarization. The data below 800 MeV confirm the previously observed structures. The cross section difference is found to change by 8.0 ± 0.5 mb between 520 MeV and 760 MeV. At the higher energies the results show no indication for similar structures or for a change of the sign of Δα L .

1 data table match query

Table 1

ERRORS INCLUDE UNCERTAINTY IN THE BEAM POLARIZATION.

Proton-Proton Collisions at 4.2 Bev

Blue, M.H. ; Lord, J.J. ; Parks, J.G. ; et al.

Phys.Rev. 125 (1962) 1386-1393, 1962.

Inspire Record 944984 DOI 10.17182/hepdata.26806

Interactions between 4.15-Bev protons and the free hydrogen nuclei in nuclear emulsion are examined. The total elastic cross section from 27 events was determined to be 11.0±2.6 mb. On the basis of 113 interactions the total inelastic cross section was found to be 28.1±3.1 mb. The partial cross sections corresponding to inelastic collisions having two, four, six, and eight secondary particles were found to be respectively 16.3±2.4, 11.5±1.8, 0.2±0.1, and 0.1±0.1 mb. While the total inelastic cross section varies slowly with energy, the partial inelastic cross sections were found to be strongly energy dependent. The observed angular distribution of elastically scattered protons in the center-of-mass system was sharply peaked in the forward and backward directions, in fair agreement with calculations based on a simple optical model applicable for energies between 2 and 10 Bev. Particles produced in inelastic collisions were identified as pions or protons by measurements of energy loss and multiple scattering. For those particles identified, center-of-mass system distributions of energy, angle, and transverse momentum are presented.

1 data table match query

Table 1

'ALL'.

p-p Interactions at 2 Bev. 2. Multiple-Pion Production

Pickup, E. ; Robinson, D.K. ; Salant, E.O. ;

Phys.Rev. 125 (1962) 2091-2101, 1962.

Inspire Record 47226 DOI 10.17182/hepdata.26793

Analyses have been made for 871 four-prong events and 463 two-prong events corresponding to multiple pion production, resulting from p−p interactions at 2 Bev in the BNL 20-in. hydrogen bubble chamber. Cross sections have been obtained for all the observable double and triple pion production processes; the branching ratios predicted by the extended isobar model are shown to be in fair agreement with the data, but there are significant differences. The c.m. momentum distributions are also in fair agreement with the predictions of the model, although there are ambiguities in the interpretation. The pion-nucleon Q values give clear evidence for the importance of the (32, 32) resonant state in multiple pion production, but consideration of this state alone does not provide an explanation of the features of double pion production. Some contribution from another state, possibly the I=12 nucleon isobar, is necessary. In double production, the c.m. angular distributions of the nucleons show backward-forward peaking suggestive of a one-pion exchange process. The angular distributions of the nucleons from triple production are almost isotropic.

1 data table match query

Table 1

No description provided.

Proton-proton interactions at 5.3 BeV

Wright, Robert W. ; Saphir, George ; Powell, Wilson M. ; et al.

Phys.Rev. 100 (1955) 1802, 1955.

Inspire Record 1188071 DOI 10.17182/hepdata.26941

None

1 data table match query

Table 1

No description provided.

p-p Interactions at 2 Bev. 1. Single-Pion Production

Fickinger, W.J. ; Pickup, E. ; Robinson, D.K. ; et al.

Phys.Rev. 125 (1962) 2082-2090, 1962.

Inspire Record 46669 DOI 10.17182/hepdata.26851

3600 two-pronged events, obtained in p−p interactions at 2 Bev in the BNL 20-in. hydrogen bubble chamber, have been analyzed. Cross sections have been measured for elastic scattering, for the two modes of single-pion production, p+p→p+n+π+, p+p→p+p+π0, and for strange-particle production. The branching ratio for the two one-pion production reactions is σ(pnπ+)σ(ppπ0)=4.17±0.25. Momentum distributions and Q values indicate that single-pion production proceeds almost entirely through the (32, 32) resonant state. The data have been considered in terms of the extended isobar model and also a one-pion exchange model for production. The branching ratio and momentum distributions can be explained by including a small effect from the I=12 resonant state in addition to the dominant I=32 resonance. The c.m. angular distribution of the nucleons in single-pion production shows very marked backward-forward peaking indicating a one-pion exchange mechanism. Absolute differential cross sections as a function of laboratory kinetic energy have been calculated from Selleri's equation for the pnπ+ reaction. There is good agreement with the data for low four-momentum transfers [q2<0.15(Bev/c)2], but for higher momentum transfers the theoretical cross sections are larger than the experimental cross sections.

1 data table match query

Table 1

No description provided.

p-p Interactions at 3 Bev

Cester, R. ; Hoang, T.F. ; Kernan, A. ;

Phys.Rev. 103 (1956) 1443-1449, 1956.

Inspire Record 945004 DOI 10.17182/hepdata.26958

Interactions initiated by 3-Bev protons of the Brookhaven Cosmotron were studied by photoemulsion technique. With appropriate criteria, 115 events are attributed to interactions of the incident beam protons with hydrogen nuclei (∼55%) and with bound protons of other nuclei (∼45%). A detailed analysis allowed the subdivision of the 115 events in categories, according to the number of π mesons (N>~0) produced in the collision. The ratio of elastic scattering to the total number of events was estimated to be σelσtotal=0.20−0.07+0.04. The observed cross section for pure elastic scattering is σel=8.9±1.0 mb. The percentages of single, double, triple, and quadruple π-meson production are respectively: 34−20+22; 35.6−23+20; 9.6−4+6; ∼1.0+3.5. Among the 20 most probable cases of single π-meson production—the estimated ratio of π+ to π0 is σπ+σπ0=5.3−1.4+0.3. The experimental results are not in agreement with the Fermi statistical-model theory (in particular the lower limit for the experimental ratio of triple to single production is given by σ3σ1>∼110 in contrast with the predicted ratio σ3σ1=167) but are not inconsistent with the Peaslee excited-state-model theory.

1 data table match query

Table 1

No description provided.