Date

Hadron Production by $e^+ e^-$ Annihilation at Center-of-mass Energies Between 2.6-{GeV} and 7.8-{GeV}. Part 2. Jet Structure and Related Inclusive Distributions

Hanson, G. ; Alam, M.S. ; Boyarski, A. ; et al.
Phys.Rev.D 26 (1982) 991, 1982.
Inspire Record 170499 DOI 10.17182/hepdata.38162

We present results on the jet structure observed in multihadronic events produced by e+e− annihilation in the Mark I magnetic detector at SPEAR. The evidence for jet structure and the jet-axis angular distribution are reported. We give inclusive distributions of the hadrons in Feynman x, rapidity, and transverse momentum relative to the jet axis.

19 data tables

Observed particle PT with respect to jet axis for events with three or more detected charged particles.

No description provided.

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Energy Dependence of Jet Measures in $e^+ e^-$ Annihilation

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Grigull, R. ; et al.
Z.Phys.C 12 (1982) 297, 1982.
Inspire Record 169193 DOI 10.17182/hepdata.16424

The jet character of the hadronic final states produced ine+e− annihilations is studied in terms of jet measures such as thrust, sphericity, jet opening angle and jet masses, in the energy range 7.7 to 31.6 GeV. All distributions and averages have been corrected for detector effects and initial state radiation. The energy dependence of the averages of these jet quantities is used to estimate the contributions due to perturbative QCD and fragmentation effects. Correlations between the jet measures and the multiplicity of charged hadrons are also presented.

12 data tables

DIFFERENTIAL THRUST DISTRIBUTIONS WHERE THRUST IS MAX(SUM(ABS(PLONG))/SUM(ABS(P))).

MEAN THRUST VALUES AS A FUNCTION OF CM ENERGY.

DIFFERENTIAL SPERICITY DISTRIBUTIONS WHERE SPHERICITY IS 3/2*MIN(SUM(PT**2)/SUM(ABS(P))).

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Measurement of Energy Correlations in $e^+ e^- \to$ Hadrons

Schlatter, D. ; Abrams, G.S. ; Amidei, D. ; et al.
Phys.Rev.Lett. 49 (1982) 521, 1982.
Inspire Record 171070 DOI 10.17182/hepdata.20563

Energy correlations have been measured with the MARK II detector at the PEP storage ring (Stanford Linear Accelerator Center) at c.m. energy of 29 GeV and are compared to first-order QCD predictions. Fragmentation processes are significant and limit the precision with which the first-order strong-coupling constant can be determined.

2 data tables

CORRELATION IS THE ENERGY WEIGHTED CROSS SECTION FOR OBSERVING THE ENERGY E1 IN THE SOLID ANGLE DOMEGA1 AND THE ANGLE E2 IN THE SOLID ANGLE DOMEGA2.SUMMED OVER ALL PAIRS OF PARTICLES IN DOMEGA1 AND DOMEGA2 AND ALL EVENTS.

MEASUREMENT OF THE STRONG COUPLING CONSTANT.


Proton - Deuteron Elastic Scattering From 20-{GeV} to 210-{GeV}

Warren, G. ; Gross, D. ; Olsen, S.L. ; et al.
Nucl.Phys.B 207 (1982) 365-373, 1982.
Inspire Record 11268 DOI 10.17182/hepdata.34079

Measurements of the differential cross section for proton-deuteron elastic scattering are reported for incident proton momenta ranging from 20 to 210 GeV and for invariant four-momentum transfers of 0.6 ≤ − t ≤ 3.0 GeV 2 . The results are in disagreement with a very simple Glauber double scattering model calculation.

1 data table

Axis error includes +- 5/5 contribution (ERROR IN RECONSTRUCTION EFFICIENCY AND ACCEPTANCE CALCULATION).


No description provided.

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Production of $\pi^0 \pi^0$ and $\pi^0 \eta$ in Photon - Photon Collisions

Edwards, C. ; Partridge, Richard ; Peck, C. ; et al.
Phys.Lett.B 110 (1982) 82-86, 1982.
Inspire Record 168793 DOI 10.17182/hepdata.30959

We investigate the four-photon final state produced in γγ colissions. In the π 0 π 0 channel we observe f(1270) production with predominantly helicity 2 and measure a partial width Γ γγ 2.9 +0.6 −0.4 ± keV (independent of assumptions on the helicity). We observe A 2 (1310) production in the π 0 η channel and find a partial width Γ γγ = 0.77 ± 0.18 ± 0.27 KeV (assuming helicity 2). We give an upper limit for f ≈ ηη .

3 data tables

Data read from graph. Systematic error on M is of order of 2% or less.

Data read from graph.

No description provided.


Study of the $e^+ e^- \to \pi^+ \pi^- \pi^+ \pi^-$ Reaction in the 1.4-{GeV} to 2.18-{GeV} Energy Range

Cordier, A. ; Bisello, D. ; Bizot, J.C. ; et al.
Phys.Lett.B 109 (1982) 129-132, 1982.
Inspire Record 168552 DOI 10.17182/hepdata.30995

New measurements of thee + e − → π + π − π + π − cross section have been performed by the magnetic detector DM1 at DCI (ORSAY) in the 1.4−2.18 GeV total energy range with statistics of 11000 events. Assuming the4 π ± production is dominated by the ϱ′(1.6) we determine its parameters: M = 1.57 ± 0.02 (stat.) −0.00 +0.06 (syst.) GeV,Γ = 0.51 ± 0.04 (stat.) −0.01 +0.04 (syst.)GeV,Γ ρ ′ee B ϱ′→ ρ 0 π + π − = 2.67 ± 0.19 (stat.) −0.36 +0.27 (syst.)keV.

1 data table

No description provided.


$\pi^0$ Production by $e^+ e^-$ Annihilation at 14-{GeV} and 34-{GeV} Center-of-mass Energy

The TASSO collaboration Brandelik, R. ; Braunschweig, W. ; Gather, K. ; et al.
Phys.Lett.B 108 (1982) 71-76, 1982.
Inspire Record 168232 DOI 10.17182/hepdata.31018

The process e + e − → π 0 + anything has been measured at c.m. energies of 14 and 34 GeV for π 0 energies between 0.5 and 4 GeV. The ratio of π 0 to π ± production for π momenta between 0.5 and 1.5 GeV/ c is measured to be 2 σ ( π 0 )/ [ σ ( π + ) + σ ( π − )] = 1.3 ± 0.4 (1.2 ± 0.4) at 14 (34) GeV. The scaled cross section ( s / μ )d σ /d x when compared with lower energy (4.9–7.4 GeV) π 0 data indicates a substantial scaling violation.

3 data tables

COMPARISON OF PI0 WITH CHARGED PION CROSS SECTIONS (SCALED BI 1/S TO SAME ENERGIES).

No description provided.

No description provided.


A Comparison of $\bar{p} p$ and $p p$ Interactions in the Central Region at $\sqrt{s}=53$-{GeV}

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Phys.Lett.B 108 (1982) 58-62, 1982.
Inspire Record 168036 DOI 10.17182/hepdata.31012

The inclusive production cross sections of pions, kaons, protons, and antiprotons in p p and pp interactions at √ s =53 GeV are compared in the kinematic range | y | < 0.8 and p T < 1.5 GeV/ c . We observe differences in the K + /K − and p /p ratios for the two data samples. Although the bulk of the particles are produced with the same momentum and rapidity distributions in p p and pp collisions, we observe difference in these distributions for produced protons and antiprotons.

3 data tables

No description provided.

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Observation of a Charge Asymmetry in $e^+ e^- \to \mu^+ \mu^-$

The JADE collaboration Bartel, W. ; Cords, D. ; Dittmann, P. ; et al.
Phys.Lett.B 108 (1982) 140-144, 1982.
Inspire Record 168234 DOI 10.17182/hepdata.31023

The angular distribution and the s dependence of the total cross section for the process e + e − → μ + μ − have been measured using the JADE detector at PETRA. After radiative corrections, a forward-backward asymmetry of −(11.8±3.8) % was observed at an average centre of mass energy of 33.5 GeV. For comparison, an asymmetry of −7.8 % is expected on the basis of the standard Glashow-Salam-Weinberg model.

5 data tables

Best fit to total cross section in energy range.

ANGULAR DISTRIBUTION.

Forward-backward asymmetry within the acceptnce region.

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