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Scattering of π−Mesons in the Momentum Range 875-1579 MeV/c from a Polarized Proton Target

Duke, P.J. ; Jones, D.P. ; Kemp, M.A.R. ; et al.

Phys.Rev. 166 (1968) 1448-1457, 1968.

Inspire Record 1407765 DOI 10.17182/hepdata.70298

Measurements have been made of the asymmetry in the scattering of π− mesons by a polarized proton target. Scattered π mesons and recoil protons were detected in arrays of scintillation counters; data were obtained at 16 scattering angles at each of 8 beam momenta between 875 and 1578 MeV/c. Analysis of these data together with earlier differential-cross-section measurements shows that there must exist at least three resonances in this energy region: (i) mass 1920 MeV/c2, Γ=170 MeV/c2, I=32, F72; (ii) mass 1682 MeV/c2, Γ=100 MeV/c2, I=12, F52; and (iii) mass 1674 MeV/c2, Γ=100 MeV/c2, I=12, D52.

33 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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A Test of quantum electrodynamics in the reaction e+ e- ---> gamma gamma (gamma)

The L3 collaboration Adriani, O. ; Aguilar-Benitez, M. ; Ahlen, S. ; et al.

Phys.Lett.B 288 (1992) 404-411, 1992.

Inspire Record 336900 DOI 10.17182/hepdata.29221

We have measured the total and differential cross sections of the reaction e + e − → γγ ( γ ) at center-of-mass energies around 91 GeV, with an integrated luminosity of 14.2 pb −1 . The results are in good agreement with QED predictions. We set lower limits, at 95% confidence level, on the QED cutoff parameters of Λ + > 139 GeV, Λ − > 108 GeV and on the mass of an excited electron of m e∗ > 127 GeV . We searched for Z 0 rare decays with photonic signitures in the final state. Upper limits, at 95% confidence level, for branching ratio of Z 0 decaying into π 0 γ / γγ , νγ and γγγ are 1.2 × 10 −4 , 1.8 × 10 −4 , 3.3 × 10 −5 respectively.

3 data tables

Table 1

Measured cross section for the 1991 data.

Table 2

Measured cross section for the 1990 data.

Table 3

Measured differential cross sections of combined 1990 and 1991 data.

Experimental Study of the Reactions $e^+ e^- \to e^+ e^-$ and $e^+ e^- \to \gamma \gamma$ at 29-{GeV}

Derrick, M. ; Gan, K.K. ; Kooijman, P. ; et al.

Phys.Rev.D 34 (1986) 3286, 1986.

Inspire Record 18585 DOI 10.17182/hepdata.23442

This paper reports measurements of the differential cross sections for the reactions e+e−→e+e− (Bhabha scattering) and e+e−→γγ (γ-pair production). The reactions are studied at a center-of-mass energy of 29 GeV and in the polar-angular region ‖costheta‖<0.55. A direct cross-section comparison between these two reactions provides a sensitive test of the predictions of quantum electrodynamics (QED) to order α3. When the ratio of γ-pair to Bhabha experimental cross sections, integrated over ‖costheta‖<0.55, is divided by the same ratio predicted from α3 QED theory, the result is 1.007±0.009±0.008. The 95%-confidence limits on the QED-cutoff parameters are Λ+>154 GeV and Λ−>220 GeV for Bhabha scattering, and Λ+>59 GeV and Λ−>59 GeV for γ-pair production.

1 data table

Table 1

No description provided.

Precision Test of {QED} by Direct Comparison of $e^+ e^- \to \gamma \gamma$ and $e^+ e^- \to e^+ e^-$ at 29-{GeV}

Derrick, M. ; Gan, K.K. ; Kooijman, P. ; et al.

Phys.Lett.B 166 (1986) 468-472, 1986.

Inspire Record 17510 DOI 10.17182/hepdata.30311

The ratio of differential cross sections for the reactions e + e − → γγ and e + e − → e + e − is measured at s = 29 GeV in the central polar angle region, |cos θ | < 0.55, and compared to the same ratio calculated by QED to order α 3 . The ratio of these ratios, integrated over this angular region, is 1.007±0.009±0.008, demonstrating excellent agreement between theory and experiment. The 95% confidence limits on the QED cut-off parameters for the γγ final state are Λ + > 59 GeV and Λ - > 59 GeV.

1 data table

Table 1

No description provided.

New Results From Bhabha Scattering at 29-{GeV}

Derrick, M. ; Gan, K.K. ; Kooijman, P. ; et al.

Phys.Lett.B 166 (1986) 463-467, 1986.

Inspire Record 17511 DOI 10.17182/hepdata.6636

Results are reported on a high statistics study of Bhabha scattering at 29 GeV in the polar angle region, |cos θ | < 0.55. The data are consistent with the standard model, and measure vector and axial-vector coupling constants of g v 2 = 0.03 ± 0.09 and g a 2 = 0.46±0.14. Limits on the QED-cutoff parameters are Λ + > 154 GeV and Λ - > 220 GeV. Lower limits on scale parameters of composite models are in the range 0.9–2.8 TeV. The partial width of a hypothetical spin-zero boson decaying to e + e − has an upper limit which varies from 6 to 57 MeV corresponding to a boson mass in the range 45–80 GeV/ c 2 .

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Pion-deuteron scattering near the 3-3 resonance

Gabathuler, K. ; Cox, C.R. ; Domingo, J.J. ; et al.

Nucl.Phys.B 55 (1973) 397-407, 1973.

Inspire Record 84138 DOI 10.17182/hepdata.32565

The elastic scattering of positive pions by deuterium has been studied using a scintillating target to detect the recoil deuteron. In addition to the angular distribution measured for 256 MeV incident energy, the energy variation of the fixed angle cross section ( θ lab =160°) has been determined between 141 MeV and 256 MeV. The former is in qualitative agreement with a simple multiple-scattering calculation, but the energy dependence is poorly reproduced.

6 data tables

Table 1

'SMALL-ANGLE TECHNIQUE' - CALIBRATED AT THETA(RF=LAB) OF 30 DEG.

Table 2

'SMALL-ANGLE TECHNIQUE' - CALIBRATED AT THETA(RF=LAB) OF 30 DEG.

Table 3

'LARGE-ANGLE TECHNIQUE' - CALIBRATED AT EACH ANGLE.

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Coincidence measurements of single pi+ electroproduction

Brown, C.N. ; Canizares, C.R. ; Cooper, W.E. ; et al.

Phys.Rev.Lett. 26 (1971) 987-991, 1971.

Inspire Record 69020 DOI 10.17182/hepdata.21506

We have studied the reaction e−+p→e−+π++n by detecting the final electron and pion in coincidence. Data are presented in the region of virtual photon mass squared from -0.18 to -1.2 GeV2, and virtual photoproduction center-of-mass energy and angle from 1.85 to 2.50 GeV and 0 to 20°, respectively.

12 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.