Fontenla, C.A.
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Pion Pair Production in Photon - Photon Collisions at {SPEAR}

Roussarie, A. ; Burke, D.L. ; Abrams, G.S. ; et al.
Phys.Lett.B 105 (1981) 304-308, 1981.
Inspire Record 166578 DOI 10.17182/hepdata.31056

We report a measurement of the cross section for the process γγ → π + π − at invariant masses 500 MeV/ c 2 < m ππ <2000 MeV/ c 2 . A value for the radiative width of the f(1270) tensor meson Γ f→ γγ = 3.6 ± 0.3 ± 0.5 KeV (helicity λ = 2) has been obtained from a fit to the observed ππ mass spectrum.

1 data table
Table 1

DATA REQUESTED FROM AUTHORS.


RESONANCE PRODUCTION BY TWO PHOTON INTERACTIONS AT SPEAR

Jenni, P. ; Burke, D.L. ; Telnov, Valery I. ; et al.
Phys.Rev.D 27 (1983) 1031, 1983.
Inspire Record 173430 DOI 10.17182/hepdata.23843

Two-photon interactions have been studied with the SLAC-LBL Mark II magnetic detector at SPEAR. The cross section for η′ production by the reaction e+e−→e+e−η′ has been measured at beam energies from 2.0 to 3.7 GeV. The radiative width Γγγ(η′) has been determined to be 5.8±1.1 keV (±20% systematic uncertainty). Upper limits on the radiative widths of the f(1270), A2(1310), and f′(1515) tensor mesons have been determined. A search has been made for production of the E(1420) by γγ collisions, but no signal is observed.

2 data tables
Table 1

No description provided.

Table 2

NO SIGNAL ABOVE BACKGROUND SEEN. UPPER LIMITS AT 95 PCT CL GIVEN.


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
Table 1

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.

Table 2

MEASUREMENT OF THE STRONG COUPLING CONSTANT.


RADIATIVE WIDTH OF THE A2 (1310)

The FERMILAB-MINNESOTA-ROCHESTER collaboration Cihangir, S. ; Berg, D. ; Biel, J. ; et al.
Phys.Lett.B 117 (1982) 119-122, 1982.
Inspire Record 182836 DOI 10.17182/hepdata.30869

Using the Primakoff formalism, we have extracted the radiative decay width of the A + 2 (1310) produced in coherent interactions of 200 GeV/ c π + mesons in nuclear targets. The width obtained is 295 ± 60 keV, a value consistent with quark-model predictions.

4 data tables
Table 1

NUMERICAL DATA IN FIGURE SUPPLIED BY S. CIHANGIR.

Table 2

NUMERICAL DATA IN FIGURE SUPPLIED BY S. CIHANGIR.

Table 3

NUMERICAL DATA IN FIGURE SUPPLIED BY S. CIHANGIR.

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Elastic Scattering Measurement of the Negative Pion Radius

Dally, E.B. ; Hauptman, J.M. ; Kubic, J. ; et al.
Phys.Rev.Lett. 48 (1982) 375-378, 1982.
Inspire Record 177923 DOI 10.17182/hepdata.20609

A new measurement of the elastic scattering of 250-GeV/c negative pions by electrons provides form-factor results from 0.0368

1 data table
Table 1

No description provided.


Observation of Semileptonic Decays of Charmed Baryons

Vella, E. ; Trilling, G. ; Abrams, G.S. ; et al.
Phys.Rev.Lett. 48 (1982) 1515, 1982.
Inspire Record 176986 DOI 10.17182/hepdata.19674

Direct electrons are observed in baryon events produced in e+e− annihilation at center-of-mass energies above the ΛcΛ¯c threshold. These events are attributed to charmed-baryon pair production and subsequent Λc semileptonic decay. Various semileptonic branching ratios of the Λc are determined, including B(Λc→e+X)=(4.5±1.7)%.

2 data tables
Table 1

ELECTRON-BARYON RATIO ABOVE AND BELOW LAMBDA/C THRESHOLD.

Table 2

No description provided.


$D$ Meson Production in $e^+ e^-$ Annihilation at Ecm Between 3.8-{GeV} and 6.7-{GeV}

Coles, M.W. ; Abrams, G.S. ; Blocker, C.A. ; et al.
Phys.Rev.D 26 (1982) 2190, 1982.
Inspire Record 178099 DOI 10.17182/hepdata.23943

The Mark II detector at SPEAR has been used to study D-meson production in e+e− annihilation at center-of-mass energies between 3.8 and 6.7 GeV. The neutral and charged D mesons are identified from their K∓π± and K∓π±π± decay modes. Measurements of RD and of the inclusive differential cross section s dσdz are presented. The quasi-two-body cross sections σDD¯, σD*D¯, and σD*D¯* are derived from an overall fit to the D recoil spectra. No evidence was found for the associated production of charmed mesons and charmed baryons.

4 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

THE DIFFERENTIAL SCALING CROSS SECTION FOR NEUTRAL AND CHARGED D'S. DEFINITION OF Z IS 2*E(P=3)/SQRT(S).

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rivet Analysis
D*+ Production in e+ e- Annihilation at 29-GeV

Yelton, J.M. ; Feldman, G.J. ; Goldhaber, G. ; et al.
Phys.Rev.Lett. 49 (1982) 430, 1982.
Inspire Record 177606 DOI 10.17182/hepdata.20572

The production of the charmed meson state D*+ has been observed in e+e− annihilation at 29 GeV. The fragmentation function for charmed quarks appears to be peaked about z=0.5.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

UPDATED RESULT REPORTED AS PRELIMINARY IN G. TRILLING, PARIS CONFERENCE 1982.


rivet Analysis
Measurement of $s d \sigma$ / Dx for Hadron Production by $e^+ e^-$ Annihilation at $\sqrt{s}=5$.2-{GeV}, 6.5-{GeV} and 29.0-{GeV}

Patrick, J.F. ; Luth, V. ; Siegrist, J. ; et al.
Phys.Rev.Lett. 49 (1982) 1232, 1982.
Inspire Record 178416 DOI 10.17182/hepdata.20599

Measurements are presented of the inclusive charged-particle cross sections s dσdx for e+e− annihilation at center-of-mass energies of 5.2, 6.5, and 29.0 GeV. Significant scale breaking is observed in these cross sections.

1 data table
Table 1

CROSS SECTION S*D(SIG)/DX FOR CHARGED PARTICLES AT SQRT(S) = 5.2, 6.5 AND 29.0 GEV. NUMERICAL VALUES OF DATA TAKEN FROM THESIS OF J.F. PATRICK LBL-14585.


THREE PION PRODUCTION ON NUCLEI AT 200-GEV

Zielinski, M. ; Berg, D. ; Chandlee, C. ; et al.
Z.Phys.C 16 (1983) 197-204, 1983.
Inspire Record 190869 DOI 10.17182/hepdata.16390

We have carried out a systematic study of the coherent dissociation of pions into 3 pions using nuclear targets. The experiment was performed at Fermilab using a high resolution forward spectrometer. Data were taken with carbon, copper and lead targets at an incident momentum of 202.5 GeV/c. Results are presented on momentum transfers, 3-pion masses, and on the nuclearA-dependence of the production cross section.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.