Date

Study of Electron-Positron Annihilation into pi+pi- at 775 MeV with the Orsay Storage Ring

Augustin, J.E. ; Bizot, J.C. ; Buon, J. ; et al.
Phys.Rev.Lett. 20 (1968) 126-129, 1968.
Inspire Record 54563 DOI 10.17182/hepdata.21756

None

1 data table

No description provided.


Study of the phi meson production with the orsay electron-positron colliding beams

Augustin, J.E. ; Bizot, J.C. ; Buon, J. ; et al.
Phys.Lett.B 28 (1969) 517-520, 1969.
Inspire Record 56680 DOI 10.17182/hepdata.6179

We have measured the e + e − → φ reaction by the K S 0 K L 0 and 3 π decay modes of the φ. We have deduced Γ ( φ → all), Γ ( φ →e + e − ), as well as B ( φ →K S 0 K L 0 ), B ( φ →K + K − ) and B ( φ → π + π − π 0 ).

3 data tables

No description provided.

RESONANCE FIT TO 12 DATA POINTS AROUND PHI FOR EACH CHANNEL GIVES PHI WIDTH OF 4.2 +- 0.9 MEV AND BR(PHI --> PI+ PI0 PI-/PHI --> KL KS) OF 0.667 +- 0.157 (RATHER HIGH).

No description provided.


$\pi^+$ $\pi^-$ production in $e^+$ $e^-$ collisions and $\rho$-$\omega$ interference

Augustin, J.E. ; Benaksas, D. ; Buon, J. ; et al.
(1969) 35, 1969.
Inspire Record 58289 DOI 10.17182/hepdata.37427

None

1 data table

RELATIVE PRODUCTION OF PION PAIRS WITHOUT RADIATIVE CORRECTIONS.


Omega-neutral production by e-plus e-minus annihilation

Augustin, J.E. ; Benaksas, D. ; Buon, J. ; et al.
Phys.Lett.B 28 (1969) 513-516, 1969.
Inspire Record 56682 DOI 10.17182/hepdata.29065

The reaction e + e − → ω o has been measured by detecting the charged pions of the π + π − π o decay mode of the ω o. A partial decay width of ω o in e + e − : Γ e + e − =0.94±0.18 keV is deduced from this result.

1 data table

FITTED, BACKGROUND SUBTRACTED, PEAK OMEGA CROSS SECTION, CORRECTED FOR UNOBSERVED DECAYS, IS 1.82 +- 0.34 MUB. TABULATED ASSUMING CENTRAL ENERGY IS 782.6 MEV. VACUUM POLARIZATION AND RADIATIVE CORRECTIONS APPLIED.


Study of electron-positron annihilation into pi-plus pi-minus on the rho-neutral resonance

Augustin, J.E. ; Bizot, J.C. ; Buon, J. ; et al.
Phys.Lett.B 28 (1969) 508-512, 1969.
Inspire Record 56683 DOI 10.17182/hepdata.29076

The electromagnetic form factor of the pion has been determined in the ϱ o resonance region by measuring the absolute cross section of the reaction e + e − → π + π − with the Orsay storage ring. More than 800 pion pairs have been detected. The excitation curve has been fitted with a Breit-Wigner formula which leads to the following values: σ peak = (1.69 ± 0.21) 10 −30 cm 2 ; m ϱ = (770 ± 4) MeV ; Γ ϱ = (111 ± 6) MeV . The partial width of the ϱ o going into e + e − thus obtained is: Γ ϱ → e + e − =(7.36±0.7) keV .

1 data table

No description provided.


Study of the phi meson by e+ e- annihilation into charged k mesons and tests of vector dominance models

Bizot, J.C. ; Buon, J. ; Chatelus, Y. ; et al.
Phys.Lett.B 32 (1970) 416-420, 1970.
Inspire Record 63115 DOI 10.17182/hepdata.28809

We have measured the e + e − → ø reaction by its K + K − decay mode. Using our previous results on K O K O and the 3π decay mode of the ø mesons, we compute Γ ø → e + e − and then compare the whole Orsay results to theoretical predictions.

2 data tables

FITTED CROSS SECTIONS AT PHI PEAK. ONLY PHI --> K+ K- MEASURED HERE - ANALYSIS USES PREVIOUS EXPERIMENTS FOR OTHER CHANNELS: J.E. AUGUSTIN ET AL., PL 28B, 517 (1969).

EXCITATION OF K+ K- CHANNEL MEASURED AROUND PHI RESONANCE AT 13 ENERGIES.


Hadronic production by e+ e- collisions at the energy 990 mev with the orsay storage ring

Cosme, G. ; Jean-Marie, B. ; Jullian, S. ; et al.
Phys.Lett.B 40 (1972) 685-688, 1972.
Inspire Record 75666 DOI 10.17182/hepdata.28276

Data were taken at the energy 2 E = 990 MeV to search for multibody events, with the same large solid angle detector which has been used for the measurement of the ϱ , ω and φ production by e + e − annilations. Assuming a π + π − π 0 π 0 production by the quasi two-body process e + e − → ϱ → ωπ 0 we give the correspondi ng cross section σ (e + e − → π + π − π 0 π 0 ) = (1.1 ± 0.5) 10 −32 cm 2 . Since no events with 3 and 4 charged pions have been observed σ (e + e − → π + π − π 0 π − ) ⩽ 1.5 × 10 −33 cm 2 .

1 data table

RATIO TO MUON PAIR PRODUCTION CALCULATED FROM CROSS SECTION. INCLUDING SYSTEMATIC ERRORS.


pi+ pi- production by e+ e- annihilation in the rho energy range with the Orsay storage ring

Benaksas, D. ; Cosme, G. ; Jean-Marie, B. ; et al.
Phys.Lett.B 39 (1972) 289-293, 1972.
Inspire Record 73648 DOI 10.17182/hepdata.28321

A large solid angle detector has been used to observe two body events produced by electron-positron collisions in the Orsay storage ring. From the π + π − excitation curve in the ϱ region we have deduced the amplitude and the phase of the ω-ϱ interference, and the ϱ resonance paramaters: M ϱ = (775.4±7.3) MeV, Γ ϱ = (149.6 ± 23.2) MeV, √ B ( ω → π + π − ) = 0.19 ± 0.05, φ = (85.7 ± 15.3) 0 , σ ( e + e − → ϱ ) = (1.00 ± 0.13) μ b at S = M ϱ 2 , B ( ϱ → e + e − = (4.1 ± 0.5) × 10 −5 , Γ ( ϱ → e + e − ) = (6.1 ± 0.7) keV, ( g ϱ 2 /4 π ) = 2.26 ± 0.25, ( g ϱππ 2 /4 π ) = 2.84 ± 0.50.

1 data table

STATISTICAL ERRORS ONLY. CROSS SECTION AT RHO0 PEAK IS 1.00 +- 0.13 MUB FROM FIT.


Hadron Production by electron positron annihilation at 4-GeV center-of-mass energy

Litke, A. ; Hanson, G. ; Hofmann, A. ; et al.
Phys.Rev.Lett. 30 (1973) 1189-1192, 1973.
Inspire Record 85252 DOI 10.17182/hepdata.21416

We have measured the total cross section for electron-positron annihilation into three or more hadrons, with at least two charged particles in the final state. The measurement was made at a center-of-mass energy of 4 GeV with a 2π−sr nonmagnetic detector. With 88 events detected, we obtain a model-independent lower limit on the hadron production cross section of 9.6 ± 1.4 nb; a calculation of detection efficiency based on invariant phase-space production of pions leads to a total cross section of 26 ± 6 nb. This cross section is 4.7 ± 1.1 times the theoretical total cross section for e+e−→μ+μ−. The average charged multiplicity is n¯=4.2±0.6.

1 data table

No description provided.


Omega production by e+ e- annihilation

Benaksas, D. ; Cosme, G. ; Jean-Marie, B. ; et al.
Phys.Lett.B 42 (1972) 507-510, 1972.
Inspire Record 84977 DOI 10.17182/hepdata.28178

A large solid angle detector has been used to observe π + π − π 0 events produced, at the ω energy, by electron-positron collisions in the ORSAY storage ring. From the ω excitation curve we have deduced: σ ( e + e − → ω 3 π ) = (180 ± 0.20) μ b, Γ = (9.1 ± 0.8) MeV and with B( ω → π + π − π 0 ) = 0.898 ± 0.045 we have calculated Γ e + e − = (0.76 ± 0. 08) keV and g 2 ω 4π = 18.4 ± 1.8 .

2 data tables

EXPERIMENTAL CROSS SECTION INCLUDING RADIATIVE EFFECTS.

FITTED CROSS SECTION AT OMEGA PEAK, RADIATIVELY CORRECTED.