Date

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

No description provided.

No description provided.


Preliminary Result of Frascati (ADONE) on the Nature of a New 3.1-GeV Particle Produced in e+ e- Annihilation

Bacci, C. ; Celio, R.Balbini ; Berna-Rodini, M. ; et al.
Phys.Rev.Lett. 33 (1974) 1408, 1974.
Inspire Record 90991 DOI 10.17182/hepdata.21293

We report on the results at ADONE to study the properties of the newly found 3.1-BeV particle.

1 data table

No description provided.


Discovery of a Narrow Resonance in $e^+ e^-$ Annihilation

The SLAC-SP-017 collaboration Augustin, J.E. ; Boyarski, A. ; Breidenbach, Martin ; et al.
Phys.Rev.Lett. 33 (1974) 1406-1408, 1974.
Inspire Record 91761 DOI 10.17182/hepdata.21247

We have observed a very sharp peak in the cross section for e+e−→hadrons, e+e−, and possibly μ+μ− at a center-of-mass energy of 3.105±0.003 GeV. The upper limit to the full width at half-maximum is 1.3 MeV.

1 data table

No description provided.


Anti-Nucleon Production in Colliding e+ e- Beams at SPEAR

Berk, D. ; Buchanan, C.D. ; Drickey, Darrell James ; et al.
Lett.Nuovo Cim. 9 (1974) 475-478, 1974.
Inspire Record 3185 DOI 10.17182/hepdata.37333

None

1 data table

ONE EVENT SEEN - PROBABLY AN ANTIPROTON.


Hadron Production by electron-Positron Annihilation at 5-GeV Center-Of-Mass Energy

Tarnopolsky, G. ; Eshelman, J. ; Law, M.E. ; et al.
Phys.Rev.Lett. 32 (1974) 432-435, 1974.
Inspire Record 745 DOI 10.17182/hepdata.21302

We have measured the cross section σ for electron - positron annihilation into three or more hadrons, with at least two charged particles in the final state, at 5 GeV center-of-mass energy. We find a model-independent lower limit of σ>9.1±1.0nb; assuming invariant phase-space production of pions, we calculate the detection efficiency of our detector to be (45 ± 11)%, yielding a cross section σ=21±5nb. The average charged hadron multiplicity is found to be n¯=4.3±0.6.

1 data table

No description provided.


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

No description provided.


Multihadron production in e+ e- collisions up to 3 gev total center-of-mass energy

Ceradini, F. ; Conversi, M. ; D' Angelo, S. ; et al.
Phys.Lett.B 47 (1973) 80-84, 1973.
Inspire Record 95215 DOI 10.17182/hepdata.28037

New results on the multihadron production by electron and positron beams colliding with a total energy of up to 3 GeV are reported. Disregarding possible kaon final states, the ratio σ mh / σ μμ of the total multihadron cross-section to the point-like cross section for process e + e − → μ + μ − has an average value of 1.58 ± 0.25 in the energy interval 2.6–3.0 GeV. The average charged multiplicity over this energy range is 〈 n c 〉 = 2.9 ± 0.3.

1 data table

AT A MEAN ENERGY OF 2.85 GEV, THE AVERAGE MULTIHADRON CROSS SECTION IS 16.4 +- 2.6 NB (R = 1.58 +- 0.25).


Experimental Results on the Production And Decay Modes of the 3101 MeV Resonance at #techn{ADONE}

Baldini-Celio, R. ; Bacci, C. ;
Lett.Nuovo Cim. 11 (1974) 711, 1974.
Inspire Record 98139 DOI 10.17182/hepdata.37446

None

1 data table

HADRONIC WIDTH IS 26 +- 11 KEV, ELECTRON DECAY WIDTH IS 3.4 +- 1.2 KEV AND MUON DECAY WIDTH IS 2.4 +- 1.1 KEV.


The Discovery of a Second Narrow Resonance in e+ e- Annihilation

Abrams, G.S. ; Briggs, D. ; Chinowsky, William ; et al.
Phys.Rev.Lett. 33 (1974) 1453-1455, 1976.
Inspire Record 91611 DOI 10.17182/hepdata.21287

We have observed a second sharp peak in the cross section for e+e−→hadrons at a center-of-mass energy of 3.695±0.004 GeV. The upper limit of the full width at half-maximum is 2.7 MeV.

1 data table

No description provided.


Multihadron production through the photon-photon interaction

Paoluzi, L. ; Ceradini, F. ; Ferrer, M.L. ; et al.
Lett.Nuovo Cim. 10S2 (1974) 435-439, 1974.
Inspire Record 96130 DOI 10.17182/hepdata.37454

None

1 data table

TWO EVENTS SEEN WITH MASSES 800 +- 90 MEV AND 1400 +- 90 MEV. THE FIRST WHEN INTERPRETED AS ETAPRIME PRODUCTION GIVES A WIDTH OF 11, +15, -8 KEV FOR ETAPRIME --> 2GAMMA USING THE EQUIVALENT PHOTON APPROXIMATION.