HEPData Search

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Pi0 PHOTOPRODUCTION FROM HYDROGEN AT BACKWARD ANGLES

Tompkins, D.H. ; Anderson, Robert L. ; Gittelman, Bernard J. ; et al.

Phys.Rev.Lett. 23 (1969) 725-728, 1969.

Inspire Record 54854 DOI 10.17182/hepdata.21587

Cross sections for π0 photoproduction from hydrogen in the backward direction have been measured for photon energies of 6, 8, 12, and 18 GeV. The range of momentum transfer covered in these measurements is −1 (GeVc)2<u<0(GeVc)2, dσdu is found to have a backward peak and decreases with energy as s−3.0±0.2. Photoproduction of η0 and ρ0 mesons has also been observed.

12 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Electron-Positron Elastic Scattering at 5-GeV Center-Of-Mass Energy

Newman, H. ; Averill, R. ; Eshelman, J. ; et al.

Phys.Rev.Lett. 32 (1974) 483, 1974.

Inspire Record 744 DOI 10.17182/hepdata.21306

We have measured the cross section, the distribution of scattering angles, and the distribution of noncoplanarity angles for electron-positron elastic scattering at 5 GeV c. m. energy. An analysis based on 230 events with scattering angles between 50 and 130° yields a ratio of the experimental to theoretical quantum-electrodynamic cross section of 1.03 ± 0.09. The scattering-angle and noncoplanarity-angle distributions are also found to be in excellent agreement with the quantum-electrodynamic predictions.

1 data table

Table 1

No description provided.

Reaction pi- p ---> x0 n, x0 ---> 2 gamma at Momenta 15-GeV/c and 40-GeV/c

The Serpukhov-CERN collaboration Apel, W.D. ; Bertolucci, Ennio ; Donskov, S V ; et al.

Sov.J.Nucl.Phys. 25 (1977) 300, 1977.

Inspire Record 91260 DOI 10.17182/hepdata.19034

None

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Study of the Reactions pi+ p --> pi0 Delta++ (1236), eta Delta++ (1236) and eta-prime Delta++ (1236) at 16-GeV/c

The Aachen-Berlin-Bonn-CERN-Cracow-Heidelberg collaboration Honecker, R. ; Laven, H. ; Becker, L. ; et al.

Nucl.Phys.B 131 (1977) 189-208, 1977.

Inspire Record 122492 DOI 10.17182/hepdata.35195

The reactions π + p giving π 0 Δ ++ (1236), η (549) Δ ++ (1236) and η ′(958) Δ ++ (1236) are studied at 16 GeV/ c . Cross sections, differential cross sections and Δ ++ (1236) spin density matrix elements are presented. The π 0 Δ ++ (1236) differential cross section d σ d t′ indicates a dip towards t ′ = 0 and has a minimum at t ′ ≅ 0.6 GeV 2 . The Δ ++ (1236) spin density matrix elements are consistent with the predictions of the Stodolsky-Sakurai model, except perhaps near the forward direction. For ηΔ ++ (1236), the differential cross section d σ d t′ turns over in the forward direction and presents no further structure. SU(3) sum rules are tested and found to be approximately satisfied. The data agree with factorization of ϱ exchange. The effective A 2 trajectory is calculated and found to be consistent with that reported from the reaction π − p → η n.

7 data tables

Table 1

No description provided.

Table 2

NORMALIZED TO THE TOTAL CROSS SECTION OF 49 MUB.

Table 3

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Neutral Pion Production in $K^+ p$ Interactions at 32-{GeV}

The French-Soviet & CERN-Soviet collaborations Azhinenko, I.V. ; Belokopytov, Yu.A. ; Borovikov, A.A. ; et al.

Nucl.Phys.B 162 (1980) 61-78, 1980.

Inspire Record 131232 DOI 10.17182/hepdata.8076

Inclusive and semi-inclusive distributions of γ's and π 0 's in the reactions K + p → γ + X and K + p → π 0 + X at 32 GeV/ c are presented and discussed. When compared to the inclusive π − production, the π 0 cross section is found to be significantly higher in low | x | and p T regions. The data are compared with other experiments and quark fusion model predictions.

7 data tables

Table 1

No description provided.

Table 2

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Table 3

ESTIMATED FROM GAMMA AND 2GAMMA SPECTRA.

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Inclusive Electron Production in Multiprong Events Produced by $e^+ e^-$ Annihilation

Feller, J.M. ; Litke, A. ; Madaras, R. ; et al.

Phys.Rev.Lett. 40 (1978) 1677, 1978.

Inspire Record 129962 DOI 10.17182/hepdata.38080

We have measured inclusive electron production in multiprong events produced by e+e− annihilation in the center-of-mass energy range 3.9-7.4 GeV. We find the electron momentum spectra are consistent with the electrons coming mainly from decays of charmed particles, with a smaller contribution from decays of the τ lepton. From our data we calculate the average branching ratio for charmed particles to decay into an electron plus additional particles to be (8.2±1.9)%.

1 data table

Table 1

No description provided.

Low Mass Electron Pair Anomaly in 17-{GeV}/c $\pi^- P$ Collisions

Stekas, J. ; Abshire, G. ; Adams, M.R. ; et al.

Phys.Rev.Lett. 47 (1981) 1686-1689, 1981.

Inspire Record 172147 DOI 10.17182/hepdata.20624

Inclusive e+e− production in 17-GeV/c π−p collisions has been measured. An excess of e+e− pairs over those from known sources for 0.1<~mee<~0.6 GeV and x<0.5 was found. No evidence is found for enhancements in specific final states involving electrons and photons or charged particles. The photon multiplicity associated with these pairs is measured.

1 data table

Table 1

No description provided.

Observation of Semileptonic Decays of Charmed Baryons

Vella, E. ; Trilling, G. ; Abrams, G.S. ; et al.

Phys.Rev.Lett. 48 (1982) 1515, 1982.

Inspire Record 176986 DOI 10.17182/hepdata.19674

Direct electrons are observed in baryon events produced in e+e− annihilation at center-of-mass energies above the ΛcΛ¯c threshold. These events are attributed to charmed-baryon pair production and subsequent Λc semileptonic decay. Various semileptonic branching ratios of the Λc are determined, including B(Λc→e+X)=(4.5±1.7)%.

2 data tables

Table 1

ELECTRON-BARYON RATIO ABOVE AND BELOW LAMBDA/C THRESHOLD.

Table 2

No description provided.

Limit on the B ---> u Coupling from Semileptonic B Decay

The CLEO collaboration Chen, A. ; Goldberg, M. ; Horwitz, N. ; et al.

Phys.Rev.Lett. 52 (1984) 1084, 1984.

Inspire Record 199380 DOI 10.17182/hepdata.20474

We have used the momentum spectrum of leptons produced in semileptonic B-meson decays to set a 90%-confidence-level upper limit on Γ(b→ulν)Γ(b→clν) of 4%. We also measure the semileptonic branching fractions of the B meson to be (12.0±0.7±0.5)% for electrons and (10.8±0.6±1.0)% for muons.

2 data tables

Table 1

No description provided.

Table 2

No description provided.