Seljak, U.
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Preliminary Result of Frascati (ADONE) on the Nature of a New 3.1-GeV Particle Produced in e+ e- Annihilation

Bacci, C. ; Celio, R.Balbini ; Berna-Rodini, M. ; et al.
Phys.Rev.Lett. 33 (1974) 1408, 1974.
Inspire Record 90991 DOI 10.17182/hepdata.21293

We report on the results at ADONE to study the properties of the newly found 3.1-BeV particle.

1 data table
Table 1

No description provided.


Single Pion Production in p n Collisions at 11.6-GeV/c

Hochman, D. ; Eisenberg, Y. ; Karshon, U. ; et al.
Nucl.Phys.B 80 (1974) 45-60, 1974.
Inspire Record 1100 DOI 10.17182/hepdata.32173

The process pn → pp π − is studied in pd collisions at 11.6 GeV/ c . A broad low-mass enhancement of p π − is found in the diffractive reaction pn → p(p π − ) with a cross section slightly smaller than that of a similar analysis at 7.0 GeV/ c . The non-diffractive reaction pn → (p π − )p shows some evidence for resonance production and its cross-section dependence on energy is characteristic of meson exchange. Samples of mass, momentum transfer, and decay angular distributions are compared with the predictions of a double Regge model and a reggeized one-pion exchange model. Using in addition information from the reactions pp → pp π 0 , pp → pn π + at 12.0 GeV/ c , an isospin analysis of the single pion production reaction from nucleon-nucleon scattering, N 1 N 2 → N 3 (N 4 π ) is presented.

1 data table
Table 1

NON-DIFFRACTIVE CHARGE-EXCHANGE CROSS SECTIONS.


Multiplicities, topological cross-sections, and single particle inclusive distributions from p p interactions at 12-GeV/c and 24-GeV/c

The Bonn-Hamburg-Munich collaboration Blobel, V. ; Brandenburg, G.W. ; Fesefeldt, H. ; et al.
Nucl.Phys.B 69 (1974) 454-492, 1974.
Inspire Record 94379 DOI 10.17182/hepdata.32358

Results on multiplicities, topological cross sections, total particle production cross sections, and correlations between charged particle and π 0 production are presented for pp interactions at 12 and 24 GeV/ c incident laboratory momentum. Inclusive production of π ± , K s 0 , p , Λ, Σ ± and Λ is studied; particle spectra are shown in single and double differential form and are compared, in different kinematic regions, with data obtained at other incident momenta and with other beam particles.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Structure in the omega pi pi System at the A2 Mass Region

Karshon, U. ; Mikenberg, G. ; Pitluck, S. ; et al.
Phys.Rev.Lett. 32 (1974) 852, 1974.
Inspire Record 761 DOI 10.17182/hepdata.21283

Evidence is presented for an enhancement in the ωππ mass spectrum at the A2 mass region in π+p interactions at 5 GeV/c. Assuming this effect to be the A2, we calculate the decay rate relative to the ρπ decay mode and obtain the results 0.29 ± 0.08 and 0.10 ± 0.04 for the two final states A20Δ++ and A2+p, respectively. Possible explanations of the discrepancy between these numbers are suggested.

1 data table
Table 1

No description provided.


Production of f0 mesons in 4.5-gev/c pi- p interactions

Holloway, L.E. ; Huld, B. ; Jordan, M. ; et al.
Phys.Rev.D 9 (1974) 1161-1170, 1974.
Inspire Record 92997 DOI 10.17182/hepdata.21996

An optical spark chamber and neutron time-of-flight spectrometer experiment studied the reaction π−p→π+π−n at incident pion momentum of 4.5 GeVc in the mass region of the f0 meson. Analysis of the data shows no evidence for anomalous structure in the f0 mass spectrum. The two-pion differential cross section in the f0 region is consistent with Wolf's one-pion-exchange model for momentum transfers (squared) −t≲0.7 (GeVc))2. The differential cross section is larger than that predicted at high momentum transfer, and may be attributed to natural-parity-exchange contributions as evidenced in the f0 decay distribution.

2 data tables
Table 1

No description provided.

Table 2

DIPION PRODUCTION CROSS SECTION NORMALIZED AT LOW -T TO A WOLF-MODEL F CROSS SECTION OF 400 MUB.


Pi0 electroproduction at the delta(1236) resonance at a four-momentum transfer of q-squared = 0.3(gev/c)-squared

Baetzner, K. ; Beck, U. ; Becks, K.H. ; et al.
Nucl.Phys.B 76 (1974) 1-14, 1974.
Inspire Record 94609 DOI 10.17182/hepdata.32274

The reaction e − + p → e − + p + π 0 has been studied in the region of the Δ (1236) resonance at a four-momentum transfer of the virtual photon of 0.3 (GeV/ c ) 2 . Angles and momenta of the secondary electron and of the outgoing proton were measured in coincidence to obtain the angular dependence of the differential cross section. The angular distribution for s- and p-waves of the pion in the πN cm-system was fitted to the cross section for three W -bins around the maximum of the resonance. The contribution of the resonant multipoles M 1+ , E 1+ and S 1+ to the cross section as well as the contribution of the background amplitudes M 1− , E 0+ and S 0+ are given.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


Photoproduction of phi mesons on protons at 2.0 gev

Besch, H.J. ; Hartmann, G. ; Kose, R. ; et al.
Nucl.Phys.B 70 (1974) 257-271, 1974.
Inspire Record 94756 DOI 10.17182/hepdata.32317

At the Bonn 2.5 GeV synchrotron the differential photoproduction cross section d σ /d t of φ mesons has been measured at a photon energy of 2.0 GeV at fibe different t values between 0.23 < | t | < 0.73 (GeV/ c ) 2 . The φ meson was detected by magnetic momentum analysis of both charged decay K mesons and by a time of flight and angle measurement of the coincident recoil proton. We found an exponential behaviour for the t dependence of the cross section. The measured slope of the exponential decrease was b = (4.01 ± 0.23) (GeV/ c −2 . This result, combined with previous measurements at higher energies, implies that the slope of the pomeron trajectory is compatible with zero. In addition the experiment yielded a value of the φ mass, m φ = (1019.4 ± 0.8) MeV and a value of the φ width, Γ = (4.4 ± 0.4) MeV.

1 data table
Table 1

No description provided.


Electroproduction of eta-mesons at the s(11)(1535) resonance

Beck, U. ; Becks, K.H. ; Burkert, V. ; et al.
Phys.Lett.B 51 (1974) 103-105, 1974.
Inspire Record 95168 DOI 10.17182/hepdata.27938

The reaction e − + p → e − + p + η has been studied in the region of the S 11 (1535)-resonance by detecting the recoil proton in coincidence with the scattered electron. The reaction has been observed at three four-momentum transfers of the virtual photon: q 2 = 0.2, 0.28 and 0.4 (GeV/ c ). First results of the differential cross section measurements are given and compared with quark model calculations.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Topological and Leading Particle Cross-Sections for 147-GeV/c $\pi^- p$ Interactions.

Fong, D.G. ; Heller, M. ; Shapiro, A.M. ; et al.
Phys.Lett.B 53 (1974) 290-296, 1974.
Inspire Record 93415 DOI 10.17182/hepdata.27916

Results are reported based on a study of π − p interactions at 147 GeV/ c in the FERMILAB 30-inch Proportional Wire Hybrid Bubble Chamber System. We have measured the topological cross sections and separated two-prong elastic and inelastic channels. In addition, we have extracted leading particle cross sections using the increased momentum resolution of the downstream proportional wire chambers. We have compared our results with experiments and predictions of a simple fragmentation hyphothesis.

1 data table
Table 1

No description provided.


Photoproduction of neutral pions off hydrogen at photon energies between 0.55 and 2.2 gev at a cm-angle of 120 degrees

Feller, P. ; Herr, H. ; Hilger, E. ; et al.
Phys.Lett.B 49 (1974) 197-200, 1974.
Inspire Record 95299 DOI 10.17182/hepdata.27964

The differential cross section has been measured for the reaction γ +p→ π o + p at the Bonn 2.5 GeV electron synchrotron in the energy range from 0.55 to 2.2 GeV at a c.m.angle of 120 degrees.

1 data table
Table 1

No description provided.