HEPData Search

The production of multipion events by e + e − annihilation has been measured at centre of mass energies 915,990 and 1076 MeV. Both channels e + e − → π + π − π o and e + e − → π + π − π + π − have been analysed. An energy threshold effect analysed. An energy threshold effect around 919 MeV ( m ω + m π o ) has been evidenced for the π + π − π o π o channel and the cross section is consistent with the quasi two-body process e + e − → ωπ o . The cross section for π + π − π + π − is lower by an order of magnitude and increases with the energy.

2 data tables

Table 1

SYSTEMATIC ERROR INCLUDED. RADIATIVE EFFECT (<15 PCT) INCLUDED.

Table 2

MULTIHADRON PRODUCTION CROSS SECTION DEDUCED AS SUM OF FOUR PION CHANNELS.

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

Table 1

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

Date

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Reactions Reset

Observables

CM Energies (GeV)

Authors Reset

MULTI - HADRON PRODUCTION IN E+ E- ANNIHILATION AT 1.45-GEV - 1.61-GEV center-of-mass ENERGY

Multi-Hadron Production from e+ e- Annihilation at 1.6 Center-of-Mass Energy

Multi-Pion Production Below 1.1-GeV by e+ e- Annihilation

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