Date

Measurement of the e+ e- ---> pi+ pi- pi0 and e+ e- ---> omega pi+ pi- reactions in the energy interval 1350-MeV - 2400-MeV

The DM2 collaboration Antonelli, A. ; Baldini, R. ; Biagini, M.E. ; et al.
Z.Phys.C 56 (1992) 15-20, 1992.
Inspire Record 339265 DOI 10.17182/hepdata.14555

The cross sections fore+e−→π+π−π0 ande+e−→ωπ+π− have been measured in the 1.35 ≦\(\sqrt s \) ≦2.4 GeV range from 1900 nb−1 collected by DM2 at DCI. The second process proceeds via a resonant state at ≈- 1660 MeV/c2, ≈- 280 MeV/c2 wide. The first one is larger than a VDM extrapolation from the ω-ϕ peaks and, although does not show any clear structure, is compatible with the presence of the above resonance.

2 data tables match query

No description provided.

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Observation of an isoscalar vector meson at approximately = 1650-MeV/c**2 in the e+ e- ---> K anti-K pi reaction

Bisello, D. ; Busetto, G. ; Castro, A. ; et al.
Z.Phys.C 52 (1991) 227-230, 1991.
Inspire Record 318558 DOI 10.17182/hepdata.14928

The\(e^ +e^ -\to K_s^0 K^ \pm\pi ^ \mp\) andK+K−π0 cross sections have been measured in the energy interval\(1350 \leqq \sqrt s\leqq 2400\) with the DM2 detector at DCI. The\(K_s^0 K^ \pm\pi ^ \mp\) cross section shows the contribution of an isoscalar vector meson at ≈1650 MeV/c2 in agreement with a previous experiment. The low statisticsK+K−π0 measurement is consistent with the above result.

2 data tables match query

The K0S K+- PI-+ cross section.

The K+ K- PI0 cross section.


K0(s) k0(l) production by e+ e- annihilation at phi energy

Cosme, G. ; Jean-Marie, B. ; Jullian, S. ; et al.
Phys.Lett.B 48 (1974) 159-161, 1974.
Inspire Record 95372 DOI 10.17182/hepdata.27993

Data have been taken at the φ energy with the same large solid angle detector which has been used for the measurement of the ϱ and ω production by e + e − annihilations. From the φ → K o L K o S π + φ − excitation curve we have deduced the φ width Γ φ = (3.81 ± 0.37) MeV and the cross-section σ e + e − → K o L K o S = (1.48±0.08±0.12) μ b. (the quoted errors are respectively statistical and systematical.)

2 data tables match query

EXPERIMENTAL CROSS SECTION INCLUDING RADIATIVE EFFECTS.

FITTED CROSS SECTION AT PHI PEAK, RADIATIVELY CORRECTED.


Pi+ pi- pi0 and pi pi gamma production by e+ e- annihilation in the phi energy range with the orsay storage ring

Cosme, G. ; Jean-Marie, B. ; Jullian, S. ; et al.
Phys.Lett.B 48 (1974) 155-158, 1974.
Inspire Record 95375 DOI 10.17182/hepdata.28017

A large solid angle detector has been used to observe π + π − π o events produced at the φ energy by electron-positron collisions in the Orsay storage ring. Fitting our data with a Breit and Wigner curve, with a fixed width Γ = (3.8±0.4) MeV coming from K O S K O L analysis, we deduce σ e + e − → π + π − π O = (0.70±0.13) μ bat 2 E = Mφ . Using our measurements on the other φ decay modes we deduce ( φ → π + π − π o )/( φ → K o S K o L ) = 0.47±0.06 and ( φ → η o γ )/( φ → K o S K o L ) = 0.077±0.022. Assuming ( φ → K + K − )/( φ → K o S K o L ) = 1.60, we derive σ TOT = (4.7±0.4) μ b, Γ e + e − = (1.27±0.11 keV and g 2 o /4 π = 14.3±1.3 (without finite width correction). Furthermore (from the observation of the ππγ coplanar events) we put an upper limit to the mode e + e − → φ π + π − γ , Γ ( φ → π + π − γ ) ⩽ 0.007 Γ ( φ → Total ) with 90% C.L.

2 data tables match query

EXPERIMENTAL CROSS SECTIONS INCLUDING RADIATIVE EFFECTS.

FITTED PARTIAL AND TOTAL CROSS SECTION AT PHI PEAK, RADIATIVELY CORRECTED.


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 match query

EXPERIMENTAL CROSS SECTION INCLUDING RADIATIVE EFFECTS.

FITTED CROSS SECTION AT OMEGA PEAK, RADIATIVELY CORRECTED.


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 match query

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 match query

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


Baryon pair production in e+ e- annihilation at S**(1/2) = 2.4-GeV

The DM2 collaboration Bisello, D. ; Busetto, G. ; Castro, A. ; et al.
Z.Phys.C 48 (1990) 23-28, 1990.
Inspire Record 297706 DOI 10.17182/hepdata.15128

Search for baryon pairs production ine+e− annihilation at\(\sqrt s= 2386 MeV\) is reported. The data relate to a luminosity of 161 nb−1 collected by the DM2 experiment at DCI, the Orsay colliding ring. First measurements of directe+e− annihilation into\(\Lambda \bar \Lambda \) and ofe+e−→\(p\bar p\) at this energy are presented. First observation of a goode+e−→\(n\bar n\) candidate is reported and upper limits are given fore+e−→\(n\bar n, \Lambda \bar \sum ^0+ c.c.\) and\(\Sigma ^0 \bar \Sigma ^0 \).

5 data tables match query

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Measurement of e+ e- ---> e+ e- and e+ e- ---> mu+ mu- at SPEAR

Augustin, J.E. ; Boyarski, A. ; Breidenbach, Martin ; et al.
Phys.Rev.Lett. 34 (1975) 233, 1975.
Inspire Record 91755 DOI 10.17182/hepdata.21210

The reactions e+e−→e+e− and e+e−→μ+μ− have been measured at center-of-mass energies 3.0, 3.8, and 4.8 GeV and production angles of 50°<θ<130° over all azimuthal angles. Agreement with quantum electrodynamics is excellent. New limits for cutoff parameters in quantum-electrodynamic-breakdown models are given.

2 data tables match query

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Total Cross-Section for Hadron Production by electron-Positron Annihilation Between 2.4-GeV and 5.0-GeV Center-Of-Mass Energy

Augustin, J.E. ; Boyarski, A. ; Breidenbach, Martin ; et al.
Phys.Rev.Lett. 34 (1975) 764, 1975.
Inspire Record 100592 DOI 10.17182/hepdata.21227

The total cross section for hadron production by e+e− annihilation has been measured at center-of-mass energies between 2.4 and 5.0 GeV. Aside from the very narrow resonances ψ(3105) and ψ(3695), the cross section varies between 32 and 17 nb over this region with structure in the vicinity of 4.1 GeV.

2 data tables match query

No description provided.

MEAN CHARGED MULTIPLICITY. ERRORS ARE STATISTICAL ONLY.