Date

E+ e- annihilation into two hadrons in the energy interval 1400-2400 mev

Alles-Borelli, V. ; Bernardini, M. ; Bollini, D. ; et al.
Phys.Lett.B 40 (1972) 433-436, 1972.
Inspire Record 75693 DOI 10.17182/hepdata.28268

The proof is given for the existence of the reaction e + e − → h ± h ∓ in the energy range 1400–2400 MeV, and its energy dependence is compared with that of e + e − → e ± e ∓ , in the same experimental conditions of observation. The exponent of the s -dependence of the ratio α = (e + e − → h ± h ∓ )/ (e + e − → e ± e ∓ ) is measured to be n = 2.08 ± 0.45, in the s -range (1.96 − 5.76) GeV 2 , on the basis of 51 e + e − → h ± h ∓ events and 8918 e + e − → e ± e ∓ events observed.

1 data table

CROSS SECTION FOR PRODUCTION OF CHARGED HADRON PAIRS.


Measurement of the x0 cross-sections in pi- p interactions at 1.6 gev/c (x0 ---> neutrals)/(x0 ---> total)

Basile, M. ; Bollini, D. ; Dalpiaz, P. ; et al.
Nuovo Cim.A 3 (1971) 371-384, 1971.
Inspire Record 71622 DOI 10.17182/hepdata.37600

The reactions π−p→ n+(X0→total) and π−p→ n+(X0→neutrals) have been studied at 1.6 GeV/c with the Bologna-CERN neutron missing-mass spectrometer. Both reactions have been detected without the use of visual techniques. The results are: σ(X0→total)=(108±14) μb and σ(X0→neutrals)=(20.0±3.5) μb, giving a branching ratio Γ(X0→neutrals)/Γ(X0→total)=(18.5±2.2)%. The branching ratio for other possible, so far undetected, neutral decay modes of the X0 turns out to be (2.4±1.9)%.

1 data table

No description provided.


Further evidence for the decay mode x(0) ---> gamma gamma and determination of the branching ratio x(0) ---> gamma gamma/ x(0) ---> total

Basile, M. ; Bollini, D. ; Dalpiaz, P. ; et al.
Nucl.Phys.B 33 (1971) 29-41, 1971.
Inspire Record 68511 DOI 10.17182/hepdata.33085

41 ± 8 events of the type X 0 → γγ have been observed in a study of the reaction π − p → n(X 0 → γγ ) at 1.6 GeV/ c incident π -momentum. This provides further evidence to our previous observation of this new X 0 decay mode and allows the determination of the branching ratio Γ(X 0 →γγ) Γ(X 0 → total =(1.7 ± 0.4)%. The theoretical implications of this result are discussed.

1 data table

THIS MEASUREMENT WHEN COMBINED WITH THE ETAPRIME PRODUCTION CROSS SECTION OF M. BASILE ET AL., NC 3A, 371 (1971) YIELDS A BR(ETAPRIME --> 2GAMMA) OF 1.7 +- 0.4 PCT.


Pi- photoproduction from deuterium at laboratory energies 600 to 1250 mev

Scheffler, P.E. ; Walden, P.L. ;
Phys.Rev.Lett. 24 (1970) 952-954, 1970.
Inspire Record 62962 DOI 10.17182/hepdata.32219

The differential cross section for the reaction γ+n→π−+p was measured for laboratory photon energies between 600 and 1250 MeV, using a liquid deuterium target. The internal nucleon momentum distribution of the deuteron was used to calculate the major effect of using deuterium as a neutron target. The data show that the amplitude to excite the F15(1688) resonance is small, in agreement with a recent quark-model prediction.

29 data tables

No description provided.

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Photoproduction of $\pi^0$ from Hydrogen near the Second Pion-Nucleon Resonance

DeStaebler, H.C. ; Erickson, E.F. ; Hearn, Anthony C. ; et al.
Phys.Rev. 140 (1965) B336-B348, 1965.
Inspire Record 48749 DOI 10.17182/hepdata.26402

Angular distributions for π0 photoproduction from hydrogen at energies between 660 and 800 MeV and proton center-of-mass angles from 0° to 140° have been measured and analyzed. Some variation from a pure d32 state is seen in the resonance region. A possible high-momentum-transfer enhancement of the cross section is discussed.

13 data tables

Axis error includes +- 0.0/0.0 contribution (3 TO 10////).

Axis error includes +- 0.0/0.0 contribution (3 TO 10////).

Axis error includes +- 0.0/0.0 contribution (3 TO 10////).

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